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Soru 1Soru →

During a routine ambulatory visit, a 58-year-old male is evaluated for ongoing management of type 2 diabetes mellitus and hypertension. Eight weeks prior, his primary care provider initiated high-intensity cardiovascular risk reduction therapy with rosuvastatin. The patient states he feels well and specifically denies experiencing new-onset muscle pain, weakness, dark urine, or abdominal discomfort. His current medication regimen includes metformin, lisinopril, and rosuvastatin. His blood pressure is 128/78 mmHg128/78 \text{ mmHg}, and his heart rate is 72/min72\text{/min}. Physical examination reveals no scleral icterus, right upper quadrant tenderness, or muscle weakness.

Laboratory studies obtained today show the following:

TestResultReference Range
Aspartate aminotransferase (AST)75 U/L75 \text{ U/L}10−40 U/L10-40 \text{ U/L}
Alanine aminotransferase (ALT)90 U/L90 \text{ U/L}10−40 U/L10-40 \text{ U/L}
Creatine kinase (CK)110 U/L110 \text{ U/L}55−170 U/L55-170 \text{ U/L}
Total bilirubin0.8 mg/dL0.8 \text{ mg/dL}0.1−1.2 mg/dL0.1-1.2 \text{ mg/dL}

Baseline liver function tests prior to starting rosuvastatin were within normal limits.

Which of the following is the most appropriate next step in the management of this patient's medication regimen?

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Cevap: Maintain current rosuvastatin therapy and provide reassurance

Cevap

Maintain current rosuvastatin therapy and provide reassurance.
The correct action involves continuing the statin without modification. Statin therapy frequently causes asymptomatic, dose-dependent elevations in hepatic transaminases. Current management guidelines explicitly state that if aminotransferase levels are elevated but remain less than 3 times the upper limit of normal (ULN) and the patient is asymptomatic, the statin should be continued without dose reduction. In this scenario, the patient's AST and ALT are roughly twice the ULN, he lacks symptoms of hepatotoxicity or myopathy, and his bilirubin is normal. Therefore, reassurance and continuation of evidence-based therapy is the standard of care.

Adım Adım Çözüm

1
Evaluate the patient's clinical presentation and laboratory results.
The patient is completely asymptomatic with mild transaminase elevations (AST 75 U/L75 \text{ U/L}, ALT 90 U/L90 \text{ U/L}, both strictly <3x the upper limit of normal) and a normal creatine kinase (CK) level.
To determine the severity of potential statin-induced hepatotoxicity or myopathy before altering the treatment plan.
2
Apply clinical guidelines for statin monitoring and treatment evaluation.
Current guidelines indicate that asymptomatic elevations of transaminases <3x ULN do not require statin discontinuation, dose adjustment, or extensive diagnostic workup.
Mild hepatic enzyme elevation is a known, dose-dependent, and usually benign effect of statin therapy that often resolves or stabilizes on its own.
3
Formulate the optimal management plan.
Continue the current dose of rosuvastatin and reassure the patient.
The established cardiovascular mortality benefits of high-intensity statin therapy in a diabetic patient far outweigh the negligible risks associated with mild, asymptomatic transaminitis.

Anahtar Kavram

Management of statin-associated hepatic enzyme elevations
Tahmini Süre:1m 15s
Soru 2Soru →

A 52-year-old woman is evaluated in the emergency department for left lower quadrant abdominal pain and fever that began 24 hours ago. The pain is constant and severe. Her past medical history is significant for obesity and chronic constipation. Her temperature is 38.3°C (100.9°F), blood pressure is 128/82 mm Hg, pulse is 98/min, and respirations are 16/min. Physical examination reveals focal tenderness to palpation in the left lower quadrant with voluntary guarding, but no rebound tenderness or rigidity. Laboratory studies show a leukocyte count of 16,500/mm³. A computed tomography (CT) scan of the abdomen and pelvis with intravenous and oral contrast demonstrates focal wall thickening of the sigmoid colon, prominent pericolic fat stranding, and an adjacent 4.5-cm well-circumscribed, rim-enhancing fluid collection. No free intraperitoneal air is observed. Based on these imaging findings, which of the following is the most appropriate next step in management?

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Cevap: Percutaneous image-guided catheter drainage

Cevap

The most appropriate next step is percutaneous image-guided catheter drainage.
The correct answer is percutaneous image-guided catheter drainage. The patient's clinical presentation and CT imaging (sigmoid colon wall thickening, fat stranding) are characteristic of acute diverticulitis. Furthermore, the CT reveals a 4.5-cm rim-enhancing fluid collection, which represents a diverticular abscess (categorized as complicated diverticulitis). The standard management for a diverticular abscess greater than 3 to 4 cm in diameter is percutaneous image-guided drainage (usually via CT or ultrasound) combined with intravenous antibiotics and bowel rest. Abscesses smaller than 3 cm can typically be managed conservatively with intravenous antibiotics alone.

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1
Evaluate the patient's clinical presentation and vital signs.
The patient has signs of systemic infection (fever, leukocytosis) and localized left lower quadrant peritonitis (focal tenderness, guarding), suggesting acute colonic inflammation.
To establish the initial clinical suspicion and determine the severity of the presentation.
2
Analyze the findings on the computed tomography (CT) scan.
The CT scan shows sigmoid colon wall thickening and pericolic fat stranding, confirming diverticulitis. Crucially, it also reveals a 4.5-cm rim-enhancing fluid collection.
To differentiate uncomplicated diverticulitis from complicated diverticulitis, which dictates the treatment pathway.
3
Determine the appropriate management based on the specific imaging findings.
The 4.5-cm fluid collection indicates a large diverticular abscess. The standard of care for an abscess greater than 3 cm is percutaneous image-guided drainage in addition to antibiotics.
Antibiotics alone have a high failure rate for large abscesses, while emergent surgery is an overly aggressive first step for a contained abscess without generalized peritonitis.

Anahtar Kavram

Complicated diverticulitis with an abscess greater than 3 to 4 cm should be managed initially with percutaneous image-guided drainage, intravenous antibiotics, and bowel rest.
Soru 3Soru →

A 32-year-old woman, G2P1, at 18 weeks gestation is brought to the emergency department by emergency medical services. Her husband reports that she suddenly lost the ability to speak and developed severe weakness on her right side approximately 45 minutes ago. Upon arrival, her blood pressure is 145/88 mmHg, heart rate is 92/min, and respiratory rate is 16/min. Neurological examination reveals a dense right-sided hemiplegia, right lower facial droop, and global aphasia. Her National Institutes of Health Stroke Scale (NIHSS) score is 18. The patient is otherwise healthy, and her pregnancy has been uncomplicated. Suspecting an acute ischemic stroke with a possible large vessel occlusion (LVO), the clinical team prepares for immediate neuroimaging to determine her candidacy for reperfusion therapy.

Which of the following is the most appropriate initial sequence of imaging studies for this patient?

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Cevap: Non-contrast computed tomography (CT) of the head and CT angiography (CTA) of the head and neck

Cevap

Non-contrast computed tomography (CT) of the head and CT angiography (CTA) of the head and neck
The correct sequence for evaluating a hyperacute stroke to determine candidacy for mechanical thrombectomy is a non-contrast CT of the head (to quickly rule out intracranial hemorrhage) followed immediately by a CT angiography (CTA) of the head and neck (to identify a large vessel occlusion). Pregnancy is a common source of cognitive bias leading to inappropriate delays in imaging due to fear of radiation. However, the fetal radiation dose from a maternal head and neck CT/CTA is extremely low (less than 0.01 mGy) and far below the threshold for fetal harm (typically >50 mGy). Iodinated contrast does cross the placenta, but it is not teratogenic and its use is justified in life-threatening emergencies. The maternal benefit of rapid diagnosis and reperfusion far outweighs any theoretical fetal risk.

Adım Adım Çözüm

1
Identify the clinical syndrome and its acuity.
The patient presents with acute right hemiplegia and global aphasia starting 45 minutes ago, placing her in the hyperacute window for stroke interventions.
This establishes that time is the most critical factor, dictating that the fastest possible imaging modalities must be chosen.
2
Assess the patient's specific physiological state.
The patient is pregnant at 18 weeks gestation.
Pregnancy introduces concerns regarding fetal radiation exposure and contrast safety, which often leads to cognitive bias and inappropriate test selection.
3
Evaluate the safety profile of the required imaging.
Fetal radiation exposure from maternal head and neck CT/CTA is negligible (<0.01 mGy). Iodinated contrast crosses the placenta but is considered safe in life-threatening emergencies.
This confirms that the standard of care for acute stroke is not contraindicated by pregnancy.
4
Select the optimal imaging sequence.
Non-contrast CT of the head to rule out hemorrhage, followed immediately by CTA of the head and neck to evaluate for LVO.
This sequence provides the necessary information for mechanical thrombectomy planning with the least delay, maximizing the chance of preserving maternal neurological function.

Anahtar Kavram

In pregnant patients presenting with acute ischemic stroke, the standard rapid neuroimaging protocol (non-contrast CT followed by CTA) should not be delayed or altered, as fetal radiation risk from head and neck imaging is negligible and the maternal benefit is life-saving.
Soru 4Soru →

A 58-year-old woman is evaluated in the emergency department for sudden-onset severe dyspnea, lightheadedness, and right-sided pleuritic chest pain that began 2 hours ago. Two months ago, she underwent an uncomplicated total abdominal hysterectomy for uterine fibroids. On arrival, her temperature is 37.1°C (98.8°F), blood pressure is 108/68 mmHg, pulse is 112/min, and respirations are 24/min. Pulse oximetry shows 88% on room air. A computed tomography (CT) pulmonary angiogram reveals a large, occlusive filling defect in the main pulmonary artery extending into the right and left lobar branches. Additional review of the axial CT slices demonstrates a right ventricular to left ventricular (RV/LV) diameter ratio of 1.4, with leftward bowing of the interventricular septum, and reflux of contrast into the inferior vena cava. Immediately upon returning from the radiology suite, she becomes confused and diaphoretic; her blood pressure drops to 78/50 mmHg, and her pulse increases to 132/min. What is the most appropriate next step in patient management?

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Cevap: Administration of systemic alteplase

Cevap

Administration of systemic alteplase is the appropriate next step to rapidly relieve right ventricular outflow obstruction in this patient with massive pulmonary embolism.
This patient is presenting with a massive pulmonary embolism (PE), defined by the presence of a PE accompanied by hemodynamic instability (systolic blood pressure < 90 mmHg or a drop of > 40 mmHg). The CT imaging explicitly demonstrates pathognomonic signs of severe right ventricular strain, including an RV/LV ratio greater than 1, bowing of the interventricular septum into the left ventricle, and reflux of contrast into the inferior vena cava. When a patient with these imaging findings develops obstructive shock, immediate systemic thrombolysis (e.g., alteplase) is the standard of care. Thrombolytics accelerate clot lysis, rapidly reducing pulmonary vascular resistance and restoring right ventricular forward flow, which is life-saving in massive PE.

Adım Adım Çözüm

1
Analyze the patient's initial presentation and CT imaging findings.
The CT shows a large pulmonary artery filling defect with a right ventricular to left ventricular (RV/LV) ratio > 1, leftward septal bowing, and IVC contrast reflux.
These specific imaging markers indicate severe right ventricular strain and cor pulmonale.
2
Evaluate the change in the patient's clinical status.
The patient develops profound hypotension (78/50 mmHg), confusion, and diaphoresis.
The combination of confirmed PE with acute right heart strain and new-onset hemodynamic instability establishes the diagnosis of massive (high-risk) pulmonary embolism with obstructive shock.
3
Determine the optimal immediate management for massive pulmonary embolism.
Systemic thrombolytic therapy (e.g., alteplase) is indicated.
In the absence of absolute contraindications, thrombolytics rapidly lyse the clot, reducing pulmonary vascular resistance, restoring right ventricular output, and correcting the obstructive shock.

Anahtar Kavram

Massive pulmonary embolism is characterized by hemodynamic instability and radiographic evidence of right ventricular strain (e.g., RV/LV ratio > 1, septal bowing on CT). Immediate treatment with systemic thrombolysis is indicated to prevent cardiovascular collapse.
Soru 5Soru →

An 88-year-old boy is brought to the emergency department by his parents due to abdominal pain for the past 2424 hours. The pain initially began around his umbilicus but has now migrated to the right lower quadrant. He has had one episode of non-bilious vomiting and reports a complete loss of appetite. His temperature is 38.1∘C38.1^\circ\text{C} (100.6∘F100.6^\circ\text{F}), pulse is 105/min105/\text{min}, and blood pressure is 100/65 mmHg100/65\text{ mmHg}. Physical examination reveals a patient who lies very still on the stretcher. Abdominal examination demonstrates significant tenderness to palpation in the right lower quadrant, particularly one-third of the distance from the anterior superior iliac spine to the umbilicus. Rebound tenderness is present. Laboratory studies show a leukocyte count of 14,500/mm314,500/\text{mm}^3 with a neutrophilic predominance. Which of the following is the most appropriate initial step in diagnostic imaging?

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Cevap: Graded compression ultrasonography of the right lower quadrant

Cevap

Graded compression ultrasonography of the right lower quadrant
The correct answer is graded compression ultrasonography of the right lower quadrant. This patient presents with a classic history and physical examination for acute appendicitis (migrating pain, fever, anorexia, McBurney's point tenderness, and leukocytosis). In the pediatric population, the diagnostic approach prioritizes minimizing exposure to ionizing radiation. The ALARA (As Low As Reasonably Achievable) principle is heavily emphasized because children have rapidly dividing tissues and a longer life expectancy, making them significantly more vulnerable to radiation-induced malignancies. Therefore, graded compression ultrasonography is the universally recommended first-line imaging study. It is highly sensitive, specific, cost-effective, and completely avoids radiation exposure.

Adım Adım Çözüm

1
Analyze the patient's clinical presentation.
The patient has migrating periumbilical to right lower quadrant pain, fever, anorexia, right lower quadrant focal tenderness (McBurney's point), rebound tenderness, and leukocytosis.
These findings represent the classic toxidrome of acute appendicitis.
2
Determine the optimal diagnostic imaging pathway for a pediatric patient with this suspected diagnosis.
While computed tomography (CT) is commonly used in adults, ultrasonography is the preferred first-line imaging modality in children.
The ALARA (As Low As Reasonably Achievable) principle dictates that ionizing radiation should be minimized in children due to their increased lifetime risk of radiation-induced malignancies.
3
Select the option that matches the standard of care.
Graded compression ultrasonography of the right lower quadrant is identified.
It is highly sensitive and specific in skilled hands, non-invasive, and radiation-free.

Anahtar Kavram

In pediatric patients with suspected acute appendicitis, graded compression ultrasonography is the initial imaging modality of choice to avoid the long-term malignancy risks associated with the ionizing radiation of computed tomography.

Alternatif Yöntem

Clinical scoring systems, such as the Pediatric Appendicitis Score (PAS) or Alvarado score, can be calculated prior to imaging. If the clinical score is extremely high and surgical suspicion is certain, some pediatric surgeons may proceed directly to the operating room without imaging, though initial ultrasound remains the standard broad recommendation.
Tahmini Süre:1m 0s
Soru 6Soru →

A 48-year-old man is evaluated for refractory hypertension. Despite adherence to an optimal regimen of amlodipine, lisinopril, and chlorthalidone, his blood pressure remains consistently elevated, typically around 165/100 mm Hg. He reports occasional muscle cramps and generalized weakness. Laboratory studies reveal a serum potassium level of 2.9 mEq/L. Subsequent screening demonstrates a plasma aldosterone concentration (PAC) of 26 ng/dL and a plasma renin activity (PRA) of 0.4 ng/mL/hr. He then undergoes an intravenous saline infusion test, which shows a post-infusion serum aldosterone level of 16 ng/dL (normal suppression < 5 ng/dL). A high-resolution contrast-enhanced computed tomography (CT) scan of the abdomen reveals a 1.4-cm hypodense, lipid-rich nodule in the right adrenal gland, with a normal-appearing left adrenal gland. The patient has no significant comorbidities and expresses a strong preference for a definitive surgical cure if possible. Which of the following is the most appropriate next step in the diagnostic workup?

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Cevap: Bilateral adrenal venous sampling

Cevap

The correct answer is bilateral adrenal venous sampling. In patients over the age of 35 with biochemically confirmed primary hyperaldosteronism, anatomic imaging is insufficient to definitively lateralize the source of aldosterone excess, necessitating functional evaluation before any surgical intervention.
The correct next step is bilateral adrenal venous sampling (AVS). The patient has a biochemically confirmed diagnosis of primary hyperaldosteronism. The next phase of the diagnostic workup is subtype evaluation to distinguish between a unilateral aldosterone-producing adenoma (which is treated surgically) and bilateral idiopathic adrenal hyperplasia (which is treated medically). While the CT scan demonstrates a unilateral nodule, non-functioning adrenal incidentalomas are found in up to 10% of patients over the age of 40. Consequently, anatomic imaging alone has a high error rate for lateralization in this age demographic. To prevent inappropriate adrenalectomy, clinical guidelines mandate that all surgical candidates over the age of 35 undergo AVS, the gold standard functional test, to prove that aldosterone hypersecretion is lateralized to the gland with the nodule.

Adım Adım Çözüm

1
Interpret the initial screening and confirmatory laboratory results.
The elevated PAC/PRA ratio (>20) and lack of aldosterone suppression during the saline infusion test (>5 ng/dL) definitively establish the diagnosis of primary hyperaldosteronism.
Before pursuing subtype evaluation or localization, the biochemical diagnosis of primary hyperaldosteronism must be unequivocally confirmed.
2
Analyze the anatomic imaging findings in the context of the patient's demographics.
The CT shows a unilateral right adrenal nodule. However, the patient is 48 years old.
Anatomic imaging (CT) is the first step in subtype evaluation to visualize the glands and rule out large carcinomas.
3
Apply the age-based clinical guidelines for adrenal lateralization.
Because the patient is older than 35, the presence of a unilateral nodule does not reliably indicate a unilateral aldosterone-producing adenoma due to the high population prevalence of non-functioning adrenal incidentalomas.
Guidelines state that AVS can only be bypassed in young patients (<35 years) with marked primary hyperaldosteronism and a unilateral adenoma, as incidentalomas are rare in that age group.
4
Determine the necessary diagnostic procedure to allow for the patient's desired surgical cure.
Bilateral adrenal venous sampling (AVS) must be performed.
AVS is the gold standard functional test to differentiate unilateral aldosterone hypersecretion (curable by surgery) from bilateral idiopathic hyperplasia (treated medically).

Anahtar Kavram

In patients >35 years old with confirmed primary hyperaldosteronism, bilateral adrenal venous sampling is required to functionally differentiate a unilateral aldosterone-producing adenoma from bilateral adrenal hyperplasia, even if a unilateral nodule is present on CT.
Soru 7Soru →

A 68-year-old man comes to the clinic for evaluation of a 2-month history of episodic retrosternal chest pressure. The discomfort occurs reliably when he jogs or climbs more than two flights of stairs and resolves within 5 minutes of rest. He has a history of type 2 diabetes mellitus, hypertension, and mild knee osteoarthritis. His medications include metformin, amlodipine, and lisinopril. He is physically active and states that his joint pain does not limit his ability to exercise. Vital signs are within normal limits. Cardiopulmonary examination is unremarkable. A resting 12-lead electrocardiogram demonstrates normal sinus rhythm with a QRS duration of 140 milliseconds, broad notched R waves in leads I, aVL, V5, and V6, and deep S waves with ST-segment elevation in leads V1 and V2. Which of the following is the most appropriate next step in the diagnostic workup of this patient?

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Cevap: Pharmacologic vasodilator myocardial perfusion imaging

Cevap

Pharmacologic vasodilator myocardial perfusion imaging
The correct answer is pharmacologic vasodilator myocardial perfusion imaging. The patient presents with symptoms typical of stable angina and requires diagnostic stress testing to evaluate for coronary artery disease. The baseline electrocardiogram reveals a left bundle branch block (LBBB), characterized by a widened QRS complex, broad lateral R waves, and deep precordial S waves. In the presence of LBBB, standard exercise electrocardiography cannot be interpreted for ischemia due to baseline ST-segment and T-wave abnormalities. Furthermore, an elevated heart rate (via physical exercise or dobutamine) in a patient with LBBB frequently produces an artifactual, false-positive reversible septal perfusion defect on myocardial perfusion imaging, and causes paradoxical septal motion that confounds stress echocardiography. Therefore, even if the patient is physically capable of exercising, the optimal noninvasive test for a patient with LBBB is a pharmacologic stress test using a vasodilator (e.g., adenosine, dipyridamole, regadenoson) coupled with myocardial perfusion imaging. Vasodilators induce coronary hyperemia without significantly increasing the heart rate, thereby circumventing the tachycardic-induced septal artifacts associated with LBBB.

Adım Adım Çözüm

1
Analyze the patient's clinical presentation.
The patient has stable exertional chest pain relieved by rest, which is highly suspicious for stable ischemic heart disease (angina pectoris).
Establishing the pre-test probability of coronary artery disease is the fundamental first step in deciding on the need for diagnostic testing.
2
Evaluate the patient's baseline electrocardiogram (ECG).
The ECG findings (QRS > 120 ms, broad R in lateral leads, deep S in right precordial leads) are diagnostic of a left bundle branch block (LBBB).
The baseline ECG determines whether standard exercise stress testing can be interpreted accurately.
3
Determine the optimal stress testing modality based on the patient's exercise capacity and ECG findings.
Although the patient can physically exercise, the presence of a baseline LBBB invalidates standard exercise ECG and severely confounds both exercise echocardiography and exercise myocardial perfusion imaging. Therefore, a pharmacologic vasodilator stress test is required.
In patients with LBBB, increased heart rates during exercise cause delayed septal activation and impaired diastolic filling, leading to false-positive septal perfusion defects on imaging. Vasodilators avoid this tachycardic response.

Anahtar Kavram

In patients with suspected stable ischemic heart disease who have a baseline left bundle branch block (LBBB), pharmacologic vasodilator myocardial perfusion imaging is the most appropriate initial diagnostic test, regardless of the patient's physical ability to exercise.
Soru 8Soru →

A 28-year-old woman presents to the ambulatory care clinic for evaluation of vague, intermittent right upper quadrant abdominal discomfort that has been present for the past three months. She has no significant past medical history other than a 10-year history of taking combined oral contraceptive pills. Vital signs are within normal limits, and physical examination reveals a soft, non-tender abdomen with no palpable hepatomegaly. Laboratory studies, including liver function tests, basic metabolic panel, alpha-fetoprotein, and CA 19-9, are all within normal limits. Given her persistent symptoms, a multiphasic contrast-enhanced magnetic resonance imaging (MRI) of the liver is performed. The MRI reveals a solitary, 6-cm, well-demarcated lesion in the right hepatic lobe. During the arterial phase, the lesion demonstrates robust, homogeneous hyperenhancement. On the portal venous and delayed phases, the lesion becomes isointense to the surrounding normal liver parenchyma. A central stellate structure is identified within the lesion; this structure is hyperintense on T2-weighted sequences and demonstrates progressive contrast enhancement on the delayed phase. Based on the precise interpretation of these imaging findings, which of the following is the most appropriate next step in management?

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Cevap: Reassurance and routine clinical observation

Cevap

Reassurance and routine clinical observation
The correct answer is reassurance and routine clinical observation. The patient's multiphasic MRI demonstrates classical features of focal nodular hyperplasia (FNH). FNH is characterized by robust, homogeneous arterial phase hyperenhancement and becomes isointense on portal venous and delayed phases. The hallmark distinguishing feature is the presence of a central stellate scar, which is typically hyperintense on T2-weighted imaging (due to vascularity, edema, and myxoid stroma) and demonstrates progressive, delayed contrast enhancement (due to the slow accumulation of contrast within the dense fibrous tissue of the scar). Although the patient has a long history of oral contraceptive use—a strong clinical distractor that frequently baits a diagnosis of hepatic adenoma—the precise imaging characteristics exclude an adenoma, which typically lacks a delayed-enhancing central scar. FNH is a benign hyperplastic response to a localized vascular anomaly with no malignant potential and an extremely low risk of complications such as hemorrhage. Therefore, for an incidentally found or mildly symptomatic FNH with definitive imaging features, the standard of care is conservative management without the need for medication cessation, invasive biopsy, or surgical resection.

Adım Adım Çözüm

1
Analyze the clinical history and identify the diagnostic dilemma.
The patient is a young woman with a 10-year history of oral contraceptive use presenting with a large hepatic lesion. This strongly elevates clinical suspicion for a hepatic adenoma.
Recognizing risk factors is critical, but they must be carefully correlated with objective diagnostic data to avoid cognitive anchoring.
2
Interpret the specific multiphasic MRI findings provided in the stem.
The lesion shows homogeneous arterial hyperenhancement and becomes isointense on later phases. Crucially, it features a central stellate scar that is hyperintense on T2-weighted imaging and exhibits progressive, delayed contrast enhancement.
Multiphasic MRI is the gold standard for characterizing hepatic lesions. The enhancement pattern of the central scar is the defining discriminator between competing diagnoses.
3
Synthesize the imaging interpretation to establish a definitive diagnosis.
The combination of arterial hyperenhancement, isointensity on delayed phases, and a T2-hyperintense, delayed-enhancing central scar is pathognomonic for focal nodular hyperplasia (FNH).
Hepatic adenomas typically lack a central scar and show washout or isointensity on delayed phases without late central enhancement. Fibrolamellar hepatocellular carcinoma has a scar, but it is T2 hypointense and does not enhance on delayed imaging.
4
Determine the standard of care for the diagnosed condition.
Because FNH is a benign, non-neoplastic hyperplastic response to a localized vascular anomaly with virtually zero risk of malignant transformation or rupture, the standard management is reassurance and observation.
Applying the correct management protocol prevents unnecessary surgical interventions or unwarranted discontinuation of the patient's preferred contraceptive method.

Anahtar Kavram

Focal nodular hyperplasia (FNH) is characterized on MRI by a T2-hyperintense central scar that exhibits delayed contrast enhancement, distinguishing it from hepatic adenomas and fibrolamellar hepatocellular carcinomas; it is managed conservatively.
Tahmini Süre:1m 30s
Soru 9Soru →

Coworkers rush a 4545-year-old butcher into the trauma bay following an occupational accident. While cutting meat, he accidentally struck his right forearm with a large cleaver. On arrival, the patient is lethargic, extremely pale, and diaphoretic. Bright red blood is actively spurting from a deep laceration on the volar aspect of his forearm, soaking rapidly through the towel wrapped around his arm.

Vital signs are:
Temperature: 36.6∘C36.6^\circ\text{C} (97.9∘F97.9^\circ\text{F})
Blood pressure: 82/5082/50 mm Hg
Heart rate: 132132/min
Respiratory rate: 2020/min
Oxygen saturation: 97%97\% on room air

Which of the following is the single most urgent initial step in the stabilization of this patient?

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Cevap: Placement of a mechanical tourniquet proximal to the laceration

Cevap

Placement of a mechanical tourniquet proximal to the laceration
The correct answer emphasizes that in the setting of catastrophic, exsanguinating extremity hemorrhage, the most critical initial step in trauma resuscitation is stopping the bleeding. This adheres to the <C>ABCDE protocol, where <C> stands for catastrophic hemorrhage control. A mechanical tourniquet is the most rapid and reliable method to achieve temporary hemorrhage control for a massive arterial limb bleed, allowing the provider to then safely address the airway and initiate volume resuscitation.

Adım Adım Çözüm

1
Assess the patient's immediate life-threatening conditions.
The patient has a catastrophic, exsanguinating arterial hemorrhage from the right forearm and is presenting in hemorrhagic shock.
The primary trauma survey requires identifying and treating the most immediate threat to life.
2
Apply the modern trauma resuscitation protocol (<C>ABCDE).
Catastrophic hemorrhage (<C>) takes precedence over Airway, Breathing, and Circulation.
Massive bleeding must be stopped before or simultaneously with airway and volume management to prevent rapid exsanguination.
3
Select the best immediate intervention for a spurting extremity bleed.
A mechanical tourniquet is applied proximal to the wound.
Direct pressure is often insufficient for severe arterial bleeding, and a tourniquet provides rapid, definitive temporary hemorrhage control.

Anahtar Kavram

In the initial stabilization of trauma patients, catastrophic and exsanguinating hemorrhage must be controlled immediately (using a tourniquet for extremities) prior to or concurrently with airway and volume resuscitation.
Soru 10Soru →

A 34-year-old man presents to the emergency department with a 2-day history of sharp, constant right lower quadrant abdominal pain. He reports no nausea, vomiting, or changes in bowel habits. His temperature is 37.2°C (99.0°F), blood pressure is 128/78 mmHg, and pulse is 82/min. Physical examination reveals localized tenderness to palpation in the right lower quadrant without rebound or guarding. Laboratory studies show a leukocyte count of 11,500/mm³. A contrast-enhanced computed tomography (CT) scan of the abdomen and pelvis is performed. The scan reveals a 2.5-cm, oval-shaped, fat-density lesion located anterior to the ascending colon, featuring a hyperdense rim and a central high-attenuation dot. There is mild surrounding inflammatory fat stranding. The colonic wall demonstrates normal thickness, and the appendix measures 5 mm in diameter with no surrounding fluid. Based on these imaging findings, which of the following is the most likely diagnosis?

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Cevap: Epiploic appendagitis

Cevap

Epiploic appendagitis is the most likely diagnosis, characterized on CT by a fat-density lesion with a hyperdense rim and central dot.
The diagnosis is epiploic appendagitis, a benign, self-limiting condition caused by torsion or venous thrombosis of an epiploic appendage. It classically presents with focal abdominal pain mimicking appendicitis or diverticulitis. The pathognomonic CT finding is a 1- to 4-cm oval, fat-density lesion adjacent to the colon wall with surrounding inflammatory stranding. The hyperdense ring corresponds to the inflamed visceral peritoneum covering the appendage, and the 'central dot sign' represents the central thrombosed draining vein.

Adım Adım Çözüm

1
Analyze the patient's clinical presentation.
The patient has localized right lower quadrant pain and mild leukocytosis without significant systemic symptoms (e.g., normal temperature, no nausea/vomiting).
This presentation narrows the differential diagnosis to right-sided abdominal pathologies such as acute appendicitis, diverticulitis, epiploic appendagitis, and omental infarction.
2
Interpret the specific findings on the contrast-enhanced CT scan.
The CT shows a 2.5-cm, oval-shaped, fat-density lesion with a hyperdense rim and central high-attenuation dot adjacent to a normal-appearing colon. The appendix is explicitly normal.
Accurate interpretation of the imaging is required to establish the correct diagnosis and avoid unnecessary surgery or antibiotics.
3
Correlate the pathognomonic imaging sign with the correct condition.
The 'central dot sign' within a fat-density oval lesion represents a thrombosed venous appendage, which is the hallmark of epiploic appendagitis.
Identifying this specific radiographic sign reliably differentiates epiploic appendagitis from other surgical and medical causes of right lower quadrant pain.

Anahtar Kavram

Epiploic appendagitis is characterized on computed tomography by an oval, fat-density lesion adjacent to the colon, frequently displaying a hyperdense rim and a central high-attenuation dot (the central dot sign).
Soru 11Soru →

An 76-year-old woman arrives at the emergency department accompanied by her daughter. The patient reports the abrupt onset of excruciating, generalized abdominal pain that started approximately 22 hours ago. The pain is severe, constant, and associated with one episode of non-bilious emesis and an urgent need to defecate. Her medical history includes long-standing hypertension, type 2 diabetes mellitus, chronic kidney disease stage 4, and paroxysmal atrial fibrillation. She states she has not taken her prescribed apixaban for the past three weeks due to an insurance coverage issue.

Vital signs show a temperature of 37.1∘C37.1^\circ\text{C} (98.8∘F98.8^\circ\text{F}), blood pressure of 158/92 mmHg158/92 \text{ mmHg}, a heart rate of 115/min115/\text{min} with an irregularly irregular rhythm, and a respiratory rate of 22/min22/\text{min}. On physical examination, the patient appears in significant distress, writhing on the stretcher. Her abdomen is soft and non-distended. There is mild, diffuse tenderness to palpation, but no guarding, rigidity, or rebound tenderness is elicited. Bowel sounds are diminished.

Initial laboratory evaluation reveals:
TestResult
Leukocyte count16,500/mm316,500/\text{mm}^3
Hemoglobin11.4 g/dL11.4 \text{ g/dL}
Platelet count215,000/mm3215,000/\text{mm}^3
Blood urea nitrogen52 mg/dL52 \text{ mg/dL}
Serum creatinine3.4 mg/dL3.4 \text{ mg/dL} (baseline 2.5 mg/dL2.5 \text{ mg/dL})
Lactate4.9 mmol/L4.9 \text{ mmol/L}

Which of the following is the most appropriate next step in diagnostic imaging for this patient?

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Cevap: Computed tomography angiography of the abdomen and pelvis

Cevap

Computed tomography angiography of the abdomen and pelvis
The correct answer is computed tomography angiography (CTA) of the abdomen and pelvis. This patient's presentation of abrupt, severe abdominal pain that is out of proportion to physical examination findings, combined with atrial fibrillation off anticoagulation and an elevated lactate level, is highly suspicious for acute mesenteric ischemia (likely embolic). CTA is the rapid, non-invasive imaging modality of choice to establish this diagnosis, allowing for direct visualization of the mesenteric vasculature. A critical teaching point in this scenario is managing the patient's acute kidney injury on chronic kidney disease. While intravenous iodinated contrast carries a risk of contrast-associated acute kidney injury, acute mesenteric ischemia is a life-threatening, time-sensitive emergency with a very high mortality rate. The American College of Radiology guidelines dictate that intravenous contrast must never be withheld in life-threatening situations where the diagnosis depends on it.

Adım Adım Çözüm

1
Identify the primary clinical syndrome based on history and physical exam.
The patient has severe abdominal pain out of proportion to physical exam findings, an irregular rhythm (atrial fibrillation) while off anticoagulation, and an elevated lactate level.
These findings are classic for acute mesenteric ischemia, likely due to an arterial embolus from the heart.
2
Determine the optimal diagnostic imaging for the suspected condition.
Computed tomography angiography (CTA) is the gold standard for diagnosing acute mesenteric ischemia.
CTA provides rapid, high-resolution imaging of the mesenteric vasculature to identify occlusions.
3
Evaluate potential contraindications to the preferred imaging study.
The patient has an acute kidney injury superimposed on chronic kidney disease stage 4, which normally warrants caution with intravenous contrast.
Intravenous contrast can cause contrast-associated acute kidney injury.
4
Weigh the risks and benefits of contrast administration in this specific clinical context.
The risk of contrast-associated acute kidney injury is superseded by the high mortality rate of untreated acute mesenteric ischemia.
In life-threatening emergencies where a definitive diagnosis dictates immediate surgical or endovascular intervention, life-saving imaging with contrast must not be delayed or withheld.

Anahtar Kavram

In patients with suspected acute mesenteric ischemia, computed tomography angiography (CTA) is the initial imaging modality of choice. Intravenous contrast should not be withheld due to renal impairment in life-threatening emergencies.
Soru 12Soru →

A 28-year-old woman, G1P0 at 16 weeks gestation, presents to the emergency department with a 12-hour history of progressively worsening right lower quadrant abdominal pain, nausea, and vomiting. Her temperature is 38.0°C (100.4°F), blood pressure is 112/72 mmHg, and heart rate is 105/min. Physical examination reveals focal tenderness in the right lower quadrant with guarding, but no rebound tenderness. Laboratory studies show a leukocyte count of 14,500/mm³. Which of the following is the most appropriate initial imaging study to establish the diagnosis?

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Cevap: Ultrasound of the right lower quadrant

Cevap

Ultrasound of the right lower quadrant
The correct answer is ultrasound of the right lower quadrant because it avoids ionizing radiation, making it the safest and most appropriate initial diagnostic step for a pregnant patient with suspected appendicitis.

Adım Adım Çözüm

1
Identify the patient's clinical presentation.
The patient is a pregnant woman at 16 weeks gestation presenting with classic signs and symptoms of acute appendicitis (fever, leukocytosis, right lower quadrant pain, nausea).
Recognizing the likely diagnosis directs the choice of diagnostic imaging.
2
Consider imaging contraindications related to the patient's demographics.
The patient is pregnant, which makes modalities utilizing ionizing radiation (like CT scans and X-rays) relatively or absolutely contraindicated for initial workup to protect the fetus.
Minimizing fetal radiation exposure is a primary concern in the diagnostic workup of pregnant patients.
3
Select the most appropriate initial imaging modality.
Graded compression ultrasound is selected as the initial test because it is safe (no ionizing radiation), widely available, and often diagnostic.
Ultrasound is the standard-of-care first step in pregnant women with suspected appendicitis, followed by MRI if the ultrasound is indeterminate.

Anahtar Kavram

In pregnant patients with suspected acute appendicitis, graded compression ultrasound of the right lower quadrant is the most appropriate initial imaging modality due to its safety profile and lack of ionizing radiation.
Tahmini Süre:50s
Soru 13Soru →

A 55-year-old woman is evaluated in the breast clinic after a routine screening mammogram demonstrated a new cluster of fine, linear, and branching microcalcifications in the upper outer quadrant of her right breast. She has no palpable breast masses, skin dimpling, or nipple discharge. A stereotactic core needle biopsy of the calcifications is performed.

Histopathologic examination of the biopsy specimens reveals enlarged terminal duct lobular units completely expanded by a monomorphic population of atypical epithelial cells forming rigid, punched-out secondary lumens. The central portions of these involved spaces contain abundant eosinophilic amorphous debris with karyorrhectic nuclei. Associated microcalcifications are present within this central debris.

Immunohistochemical staining is performed and demonstrates a continuous, intact rim of p63 and smooth muscle myosin heavy chain (SMMHC) positive cells surrounding the involved spaces. The neoplastic cells exhibit strong, diffuse membranous staining for E-cadherin.

Based on the biopsy findings, which of the following is the most accurate diagnostic interpretation?

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Cevap: Ductal carcinoma in situ

Cevap

Ductal carcinoma in situ
The biopsy reveals expanded ducts filled with monomorphic atypical cells and central necrotic debris with microcalcifications. These architectural and cytologic features are classic for high-grade ductal carcinoma in situ (DCIS). Furthermore, the continuous rim of p63 and SMMHC positive cells confirms an intact myoepithelial layer, definitively ruling out invasive disease. Finally, the positive E-cadherin staining confirms a ductal rather than lobular origin.

Adım Adım Çözüm

1
Analyze the clinical and architectural presentation
A subclinical breast lesion identified by microcalcifications on screening mammography, showing expanded ducts with monomorphic atypical cells and central necrosis (comedonecrosis).
This establishes a high-grade, neoplastic process within the breast ducts.
2
Interpret the myoepithelial immunohistochemical markers (p63, SMMHC)
The continuous, intact rim of p63 and SMMHC positive cells confirms the presence of an intact myoepithelial cell layer.
An intact myoepithelial layer proves that the atypical cells have not breached the basement membrane, confirming the lesion is in situ and ruling out invasive carcinoma.
3
Interpret the epithelial immunohistochemical marker (E-cadherin)
Strong, diffuse membranous staining for E-cadherin is observed.
E-cadherin is a cell adhesion molecule retained in ductal carcinomas but classically lost in lobular carcinomas (due to CDH1 mutations), distinguishing this as a ductal proliferation.
4
Synthesize the diagnostic features
An E-cadherin-positive, in situ ductal proliferation with prominent comedonecrosis is established.
These combined findings are definitively diagnostic of high-grade ductal carcinoma in situ (DCIS).

Anahtar Kavram

The diagnosis of ductal carcinoma in situ (DCIS) relies on identifying malignant ductal cells (E-cadherin positive) confined within the ductal basement membrane (intact myoepithelial layer confirmed by p63/SMMHC) accompanied by classic architectural features such as comedonecrosis.
Soru 14Soru →

A 48-year-old woman comes to the clinic for a routine wellness examination. Her medical history is significant for severe persistent asthma, for which she uses a fluticasone-salmeterol inhaler, and an unprovoked deep vein thrombosis diagnosed six months ago, for which she currently takes rivaroxaban.

During the encounter, she mentions several self-initiated changes to her health routine. She states, 'I have been feeling sad lately, so I started taking an over-the-counter St. John's wort supplement. I also occasionally take my husband's propranolol when I feel anxious about my breathing. Furthermore, I read online that I should get a bone density scan to check for osteoporosis, so I want to schedule that today.'

When the physician gently expresses concern regarding her unprescribed medication use, the patient crosses her arms and says, 'I am an adult, and as a doctor, you cannot just declare me legally incompetent to make my own health choices!'

Which of the following is the most appropriate counseling response by the physician?

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Cevap: I understand you want to manage your symptoms proactively, but St. John's wort can make your blood thinner less effective and increase your risk of another clot.

Cevap

The correct response validates the patient's goal of managing her symptoms while immediately educating her on the critical drug interaction between St. John's wort and her blood thinner.
The most appropriate counseling response utilizes a patient-centered approach by validating the patient's desire to manage her symptoms, while immediately providing critical health education regarding a severe drug interaction. St. John's wort is a strong inducer of both cytochrome P450 3A4 (CYP3A4) and P-glycoprotein. Rivaroxaban is a substrate for both of these pathways. Concurrent use of St. John's wort significantly increases the clearance of rivaroxaban, leading to subtherapeutic anticoagulant levels and placing the patient at high risk for recurrent deep vein thrombosis or pulmonary embolism. Addressing this life-threatening interaction empathetically is the best initial step in counseling.

Adım Adım Çözüm

1
Analyze the patient's medication list and recent self-initiated changes for potential interactions or contraindications.
Identified two major pharmacologic issues: St. John's wort interacts with rivaroxaban, and propranolol is absolutely contraindicated in severe asthma.
Ensuring patient medication safety is the highest clinical priority before addressing other concerns.
2
Evaluate the patient's requests regarding preventive screening and ethical declarations.
A DEXA scan is not universally indicated at age 48, and the patient's statement about legal competence highlights a misunderstanding between clinical capacity and legal competence.
Patient counseling must be guided by accurate, evidence-based guidelines and precise ethical principles.
3
Select the communication response that prioritizes the most critical safety issue while maintaining appropriate physician-patient boundaries and empathy.
The statement validating her intentions but correcting the dangerous use of St. John's wort is chosen as the most appropriate health education response.
Effective health education requires providing accurate, life-saving medical information without confrontation or factual errors.

Anahtar Kavram

Patient Counseling and Health Education: Addressing dangerous drug interactions and misconceptions while validating patient concerns
Tahmini Süre:1m 30s
Soru 15Soru →

A 62-year-old woman is evaluated in the clinic for follow-up of abnormal laboratory findings. Two weeks ago, she underwent routine blood work for a wellness exam, which showed an elevated serum calcium level. She is completely asymptomatic and specifically denies fatigue, bone pain, abdominal pain, nausea, or a history of nephrolithiasis. She has no significant past medical history and takes no medications. She has no known family history of endocrine disorders.

Vital signs are within normal limits. Physical examination reveals a well-appearing woman with a normal thyroid gland on palpation and no palpable neck masses.

Repeat laboratory studies obtained today are as follows:

TestResultReference Range
Calcium, total11.4 mg/dL8.4-10.2 mg/dL
Albumin4.0 g/dL3.5-5.0 g/dL
Phosphorus2.3 mg/dL2.5-4.5 mg/dL
Creatinine0.9 mg/dL0.6-1.2 mg/dL
Intact parathyroid hormone94 pg/mL10-65 pg/mL
25-hydroxyvitamin D32 ng/mL20-50 ng/mL

A dual-energy x-ray absorptiometry (DEXA) scan demonstrates a T-score of -2.6 at the distal third of the radius and -1.8 at the lumbar spine. Because the patient meets the criteria for surgical intervention due to osteoporosis, her physician is considering a referral for parathyroidectomy.

Which of the following is the most appropriate next step in the diagnostic workup prior to surgical planning?

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Cevap: Measurement of 24-hour urinary calcium and creatinine excretion

Cevap

Measurement of 24-hour urinary calcium and creatinine excretion
The patient has hypercalcemia with an inappropriately elevated PTH, indicating PTH-dependent hypercalcemia. The primary differential diagnosis for this presentation includes primary hyperparathyroidism and familial hypocalciuric hypercalcemia (FHH). Before planning surgical intervention for primary hyperparathyroidism (which is indicated here due to her osteoporosis and degree of hypercalcemia), FHH must be excluded because parathyroidectomy does not correct the hypercalcemia in FHH and is strictly contraindicated. The most appropriate next step in the diagnostic sequence is to measure 24-hour urinary calcium excretion. In primary hyperparathyroidism, urinary calcium is typically normal or high, whereas in FHH it is low (<100 mg/day).

Adım Adım Çözüm

1
Interpret the initial laboratory findings to establish the mechanism of hypercalcemia.
The patient has hypercalcemia (11.4 mg/dL) with an inappropriately elevated intact PTH (94 pg/mL).
Elevated PTH in the setting of hypercalcemia indicates a PTH-dependent process, narrowing the differential diagnosis primarily to primary hyperparathyroidism and familial hypocalciuric hypercalcemia (FHH).
2
Evaluate the clinical indication for surgical intervention.
The patient is asymptomatic but has a DEXA scan showing osteoporosis (T-score of -2.6 at the radius) and a serum calcium > 1 mg/dL above normal.
These findings are established indications for surgical parathyroidectomy in patients with primary hyperparathyroidism, making surgical planning the next clinical goal.
3
Identify the critical diagnostic step required before referring for surgery or localization.
Measurement of 24-hour urinary calcium and creatinine excretion is required to differentiate primary hyperparathyroidism from FHH.
FHH is a benign genetic condition that mimics primary hyperparathyroidism but is treated conservatively. Parathyroidectomy is contraindicated in FHH. Localization studies should never precede this biochemical confirmation.

Anahtar Kavram

In patients with PTH-dependent hypercalcemia, 24-hour urinary calcium excretion must be measured to exclude familial hypocalciuric hypercalcemia (FHH) before obtaining localization imaging or referring for parathyroidectomy.
Tahmini Süre:1m 30s
Soru 16Soru →

A 72-year-old man who is recovering from a right total hip arthroplasty performed 3 days ago develops progressive abdominal distension, mild diffuse abdominal pain, and nausea. He has not had a bowel movement since surgery, though he reports passing flatus. His medications include oxycodone, enoxaparin, and scheduled acetaminophen. Vital signs are temperature 37.1°C (98.8°F), blood pressure 130/80 mmHg, heart rate 88/min, and respiratory rate 16/min. Physical examination shows a massively distended, tympanic abdomen with hypoactive bowel sounds. There is no guarding, rigidity, or rebound tenderness. Laboratory results are unremarkable. A supine plain abdominal radiograph demonstrates diffuse dilation of the cecum, ascending colon, and transverse colon, with a maximum cecal diameter of 9 cm. There is a continuous column of gas extending down to the rectum with no discrete transition point. No free intraperitoneal air is visualized. Based on the interpretation of these imaging findings, which of the following is the most appropriate next step in management?

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Cevap: Discontinuation of oxycodone, bowel rest, and intravenous fluids

Cevap

The correct approach is the discontinuation of oxycodone, initiation of bowel rest, and administration of intravenous fluids.
This patient presents with postoperative adynamic ileus of the large bowel, known as acute colonic pseudo-obstruction (Ogilvie syndrome). The diagnosis is supported by the abdominal radiograph demonstrating diffuse colonic dilation with a continuous column of gas extending into the rectum, without a discrete transition point. The presence of rectal gas differentiates this condition from a mechanical large bowel obstruction, which would typically show a cut-off sign and an absence of distal gas. Because the maximum cecal diameter is 9 cm (less than the 10-12 cm threshold for high perforation risk) and there are no clinical or radiographic signs of ischemia or perforation, the initial management is strictly conservative. This includes bowel rest, intravenous fluid hydration, correction of any electrolyte abnormalities, and the discontinuation of medications that decrease bowel motility, such as the opioid analgesic oxycodone.

Adım Adım Çözüm

1
Evaluate the clinical presentation.
The patient has postoperative abdominal distension and hypoactive bowel sounds while taking opioids, raising suspicion for an adynamic bowel state.
Identifying the clinical context helps narrow the differential diagnosis between functional ileus and mechanical obstruction.
2
Analyze the radiographic imaging findings.
The plain radiograph shows a 9 cm dilated cecum with a continuous column of gas reaching the rectum and no transition point.
The presence of distal colonic gas without a cut-off point confirms acute colonic pseudo-obstruction (Ogilvie syndrome) and effectively rules out a mechanical large bowel obstruction.
3
Determine the appropriate management strategy based on the imaging.
Conservative management is selected.
Because the cecal diameter is less than 12 cm (low immediate risk of perforation) and there is no free air, the standard initial treatment is supportive care and removal of exacerbating factors like opioids.

Anahtar Kavram

Acute colonic pseudo-obstruction (Ogilvie syndrome) is identified on plain radiography by diffuse colonic dilation with a continuous column of gas extending into the rectum. Initial management is conservative (bowel rest, IV fluids, discontinuing opioids) if the cecal diameter is less than 12 cm and no signs of perforation are present.
Tahmini Süre:1m 30s
Soru 17Soru →

A 6262-year-old man with a 44-year history of untreated, asymptomatic, low-grade follicular lymphoma presents with rapid enlargement of a right cervical lymph node, new-onset fevers, and a 10%10\% body weight loss over the past 66 weeks. An excisional biopsy of the rapidly enlarging node is performed.

Histopathologic and molecular evaluation reveals the following:
- Complete architectural effacement by a diffuse infiltrate of large lymphoid cells.
- The atypical cells display vesicular chromatin, prominent nucleoli, and moderate basophilic cytoplasm.
- No residual nodular or follicular architecture is identified.
- Immunohistochemistry: The large cells are strongly positive for CD20CD20, CD10CD10, BCL−2BCL-2, and BCL−6BCL-6.
- The Ki-67 proliferation index is estimated at 85%85\%.
- Fluorescence in situ hybridization (FISH) confirms the persistence of a t(14;18)(q32;q21)t(14;18)(q32;q21) translocation and identifies a newly acquired MYCMYC gene rearrangement at 8q248q24.

Which of the following is the most accurate diagnostic interpretation of this lymph node biopsy?

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Cevap: Histologic transformation to a high-grade B-cell lymphoma with MYC and BCL2 rearrangements

Cevap

The correct diagnosis is histologic transformation to a high-grade B-cell lymphoma with MYC and BCL2 rearrangements (commonly referred to as 'double-hit' lymphoma).
This patient's biopsy demonstrates a diffuse proliferation of large B-cells that harbor both a BCL2 rearrangement (evidenced by the t(14;18) translocation typical of his original follicular lymphoma) and a newly acquired MYC rearrangement. According to the WHO classification of lymphoid neoplasms, a diffuse large B-cell lymphoma or high-grade B-cell lymphoma that concurrently harbors rearrangements of MYC and BCL2 (and/or BCL6) is classified as a 'High-grade B-cell lymphoma, with MYC and BCL2 and/or BCL6 rearrangements', colloquially known as a 'double-hit' lymphoma. This pathologic interpretation is critical because double-hit lymphomas are highly aggressive and generally respond poorly to standard R-CHOP chemotherapy, requiring more intensive treatment regimens. The complete loss of follicular architecture and the acquisition of large cell morphology with a high Ki-67 index histologically confirm the transformation from his previously indolent disease.

Adım Adım Çözüm

1
Analyze the clinical history and morphologic changes.
The patient has a history of indolent follicular lymphoma but now presents with rapidly growing lymphadenopathy, systemic B-symptoms, and a biopsy showing complete architectural effacement by large lymphoid cells.
To recognize that the clinical and morphologic picture strongly indicates histologic transformation to an aggressive large cell lymphoma.
2
Interpret the immunohistochemistry (IHC) profile.
The large cells are positive for CD20, CD10, BCL-2, and BCL-6.
To establish that the transformed cells maintain a germinal center B-cell phenotype, consistent with an origin from the pre-existing follicular lymphoma.
3
Synthesize the molecular and cytogenetic data with the morphology.
FISH demonstrates both a t(14;18) (BCL2) rearrangement and a newly acquired MYC rearrangement in a diffuse large B-cell proliferation.
To apply the specific WHO classification criteria, which require this exact combination of genetic hits to diagnose a high-grade B-cell lymphoma with MYC and BCL2 rearrangements.

Anahtar Kavram

Diagnosis of high-grade B-cell lymphoma with MYC and BCL2 rearrangements ('double-hit' lymphoma) through the synthesis of morphology, immunophenotype, and FISH cytogenetics.
Soru 18Soru →

A 59-year-old male presents to the outpatient clinic reporting a three-week history of episodic right upper quadrant abdominal pain. The pain typically occurs following large meals, lasts for approximately an hour, and then resolves completely. He is currently asymptomatic. His vital signs are temperature 37.1°C (98.8°F), blood pressure 128/82 mmHg, heart rate 76/min, and respiratory rate 14/min. Physical examination reveals a soft, non-distended abdomen with mild deep palpation tenderness in the right upper quadrant, but no Murphy sign or peritoneal signs are present.

Laboratory studies are obtained and shown below:

Laboratory TestResultReference Range
Leukocyte count7,800/mm³4,500 - 11,000/mm³
Total bilirubin1.2 mg/dL0.1 - 1.2 mg/dL
Direct bilirubin0.4 mg/dL0.0 - 0.3 mg/dL
Aspartate aminotransferase (AST)95 U/L8 - 40 U/L
Alanine aminotransferase (ALT)110 U/L7 - 56 U/L
Alkaline phosphatase245 U/L44 - 147 U/L

An abdominal ultrasound demonstrates multiple echogenic foci with posterior acoustic shadowing in the gallbladder. The gallbladder wall is not thickened. The common bile duct measures 9 mm in diameter, but no obstructing calculus is directly visualized.

Which of the following is the most appropriate next step in the diagnostic evaluation of this patient?

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Cevap: Magnetic resonance cholangiopancreatography

Cevap

Magnetic resonance cholangiopancreatography
This patient presents with biliary colic, elevated liver enzymes, and a dilated common bile duct on ultrasound. However, his total bilirubin is normal and there are no signs of ascending cholangitis. This clinical picture places him at intermediate risk for choledocholithiasis. According to current clinical guidelines, intermediate-risk patients should undergo further non-invasive evaluation to confirm the presence of a common bile duct stone before proceeding to invasive procedures. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS) are the most sensitive and specific non-invasive tests for this purpose. Proceeding with MRCP allows for definitive diagnosis without exposing the patient to the risks of an invasive procedure if no stone is present.

Adım Adım Çözüm

1
Stratify the patient's risk for choledocholithiasis based on clinical, laboratory, and sonographic findings.
The patient has a dilated common bile duct (9 mm) and elevated liver enzymes, but a normal bilirubin level and no signs of acute ascending cholangitis.
Risk stratification is essential to determine whether the patient proceeds to therapeutic intervention, further non-invasive imaging, or routine surgery.
2
Categorize the specific risk level using societal guidelines (e.g., ASGE criteria).
The patient falls into the intermediate-risk category.
Intermediate risk is defined by factors such as age over 55, a dilated common bile duct on ultrasound, or abnormal liver biochemistries without overt jaundice.
3
Select the appropriate diagnostic or therapeutic pathway for the intermediate-risk category.
Non-invasive confirmatory imaging with Magnetic resonance cholangiopancreatography (MRCP) or Endoscopic ultrasound (EUS) is indicated.
This approach avoids the significant procedural risks of an invasive therapeutic procedure unless a stone is definitively confirmed.

Anahtar Kavram

Patients at intermediate risk for choledocholithiasis (abnormal liver biochemistries, dilated common bile duct, age >55) should undergo non-invasive evaluation with MRCP or EUS prior to invasive therapeutic procedures.
Soru 19Soru →

A 72-year-old man is brought to the emergency department by emergency medical services after collapsing at home. His wife reports that he complained of a sudden, tearing pain in his abdomen and lower back shortly before losing consciousness. His past medical history is significant for hypertension, hyperlipidemia, and a 50-pack-year smoking history. Upon arrival, he is lethargic, pale, and diaphoretic. Vital signs are temperature 36.8∘C36.8^\circ\text{C} (98.2∘F98.2^\circ\text{F}), heart rate 132/min, blood pressure 68/40 mmHg, and respiratory rate 24/min. Physical examination reveals a large, pulsatile midline abdominal mass and cold, mottled lower extremities. Two large-bore peripheral intravenous catheters have been successfully inserted. Which of the following is the most appropriate next step in management?

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Cevap: Activate the massive transfusion protocol and arrange immediate transfer to the operating room

Cevap

Activate the massive transfusion protocol and arrange immediate transfer to the operating room
The correct approach for a hemodynamically unstable patient with a clinically obvious ruptured abdominal aortic aneurysm (AAA) is immediate exploratory laparotomy (or endovascular repair, depending on the center's capabilities) and aggressive resuscitation with uncrossmatched blood or a massive transfusion protocol. The classic triad of a ruptured AAA is abdominal or back pain, a pulsatile abdominal mass, and hypotension, which this patient demonstrates clearly. Any delay for diagnostic testing in this scenario significantly increases the risk of death.

Adım Adım Çözüm

1
Identify the primary diagnosis and clinical state
The patient has a classic presentation of a ruptured abdominal aortic aneurysm (AAA) complicated by severe hemorrhagic shock.
Sudden tearing abdominal or back pain, a pulsatile abdominal mass, and profound hypotension (68/40 mmHg) in an older male smoker strongly indicate a ruptured AAA.
2
Determine the priority of care in an unstable surgical emergency
Immediate hemorrhage control and volume replacement with blood products are required.
In hemorrhagic shock due to a ruptured AAA, any delay in surgical repair (e.g., stopping for imaging) drastically increases mortality. The patient must go straight to the operating room.

Anahtar Kavram

Hemodynamically unstable patients with a highly suspected ruptured abdominal aortic aneurysm require immediate surgical intervention and blood product resuscitation, bypassing further diagnostic imaging.
Tahmini Süre:1m 0s
Soru 20Soru →

A 58-year-old woman presents to the ambulatory clinic complaining of a swollen and painful right calf that started two days ago. She is currently receiving chemotherapy for active ovarian cancer and reports spending most of the past week in bed due to profound fatigue. Vital signs include a temperature of 37.1°C (98.8°F), blood pressure of 128/82 mmHg, heart rate of 88/min, and respiratory rate of 14/min. Physical examination reveals pitting edema extending to the right knee, mild erythema, and localized tenderness along the popliteal vein. The right calf circumference is measured to be 4.5 cm larger than the left calf. Which of the following is the most appropriate next step in evaluating this patient's condition?

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Cevap: Compression ultrasonography of the right lower extremity

Cevap

Compression ultrasonography of the right lower extremity
The correct answer is compression ultrasonography of the right lower extremity. This patient presents with multiple high-risk features for deep vein thrombosis (DVT), including active cancer, recent bedridden status, localized tenderness, and significant unilateral calf swelling. These clinical features result in a high Wells score, indicating a high pretest probability for DVT. According to evidence-based diagnostic sequencing guidelines, the most appropriate initial diagnostic step for a patient with a high pretest probability is a non-invasive venous compression ultrasonography.

Adım Adım Çözüm

1
Assess the patient's pretest probability for deep vein thrombosis (DVT).
The patient has active cancer, recent immobilization, significant unilateral calf swelling (> 3 cm difference), and localized venous tenderness, yielding a high Wells score (≥ 3).
Determining the clinical pretest probability dictates the sequence of the diagnostic workup.
2
Select the appropriate initial diagnostic test based on the established high pretest probability.
Compression ultrasonography is indicated as the first step.
In high-probability patients, the initial test of choice is a non-invasive compression ultrasound. A D-dimer is not sequenced first because a negative result cannot reliably rule out DVT in high-risk patients.

Anahtar Kavram

In patients with a high pretest probability for deep vein thrombosis (DVT) based on the Wells criteria, the correct next diagnostic step is compression ultrasonography, bypassing the D-dimer assay.
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