Examkin

All practice questions

858 questions

All types4,736Multiple choice2,413Multiple select567Numeric127Matching858Ordering771
Question 141Question →

A hospital's antimicrobial stewardship committee is reviewing mechanisms of antibiotic resistance among distinct bacterial isolates. Match each clinical isolate and its characteristic resistance profile with the primary molecular mechanism responsible for its resistance.

Click a left item, then click its matching right item

Items

Streptococcus pneumoniae with high-level resistance to ceftriaxone
Pseudomonas aeruginosa with isolated resistance to imipenem
Klebsiella pneumoniae resistant to all beta-lactams including carbapenems via a plasmid
Mycoplasma pneumoniae intrinsically resistant to penicillins and cephalosporins

Matches

Show answer & explanation

Answer

Streptococcus pneumoniae pairs with altered PBPs; Pseudomonas aeruginosa pairs with loss of porins; Klebsiella pneumoniae pairs with hydrolytic inactivation by a beta-lactamase; Mycoplasma pneumoniae pairs with absence of a cell wall target.
Each bacterial isolate utilizes a distinct, well-characterized mechanism to evade antimicrobial action. S. pneumoniae alters its target site (PBPs). P. aeruginosa restricts drug entry by losing the OprD porin. K. pneumoniae enzymatically destroys the drug via a carbapenemase. M. pneumoniae intrinsically lacks the structural target (cell wall) entirely.

Step-by-Step Solution

1
Identify the pathogen and its specific resistance phenotype from the given left items.
The pathogens are S. pneumoniae, P. aeruginosa, K. pneumoniae, and M. pneumoniae.
Pathogen identification is the first step in determining the likely resistance mechanism.
2
Recall the characteristic molecular mechanism of resistance for each pathogen-drug combination.
S. pneumoniae uses altered PBPs; P. aeruginosa loses OprD for imipenem; K. pneumoniae uses KPC (carbapenemase); M. pneumoniae lacks a cell wall.
Linking the phenotype to the genotype/molecular mechanism is required to make the correct matches.
3
Pair each isolate with the corresponding molecular mechanism on the right.
All four pairs are successfully matched.
Completes the matching requirement of the question.

Key Concept

Molecular mechanisms of antimicrobial resistance in clinically significant bacteria
Question 142Question →

Match each of the following patient clinical scenarios, which highlight specific environmental or occupational exposure histories, to the most appropriate diagnostic evaluation pathway.

Click a left item, then click its matching right item

Items

A previously healthy female agricultural worker in New Mexico who develops acute febrile illness and rapid-onset respiratory failure shortly after sweeping an enclosed, mouse-infested shed.
A male recreational cave explorer from the Midwestern United States who presents with a protracted cough, unintentional weight loss, and the development of painful ulcerations on the hard palate.
A female avian rescue volunteer who develops a sudden onset of high fever, intractable headache, myalgias, and a dry cough two weeks after taking in several sick cockatiels.
An older male with a long career in building insulation and brake manufacturing who presents with insidious-onset dyspnea on exertion, bibasilar end-inspiratory crackles, and digital clubbing.

Matches

Show answer & explanation

Answer

The agricultural worker matches with Sin Nombre virus (Hantavirus); the cave explorer matches with Histoplasma capsulatum; the avian volunteer matches with Chlamydia psittaci; and the insulation worker matches with pneumoconiosis.
Each patient's clinical presentation is strongly tied to a classic environmental or occupational exposure. Correct diagnosis requires integrating the geographic location, specific vector or material exposure, and the temporal onset of symptoms.

Step-by-Step Solution

1
Analyze the exposure history and clinical onset for the agricultural worker.
Exposure to a mouse-infested shed in the Southwest US followed by acute respiratory failure points to Hantavirus pulmonary syndrome caused by the Sin Nombre virus.
Identifying the geographic location (New Mexico) and specific vector (rodents/mice) is critical for prioritizing infectious etiologies in acute respiratory distress.
2
Analyze the exposure history and clinical signs for the cave explorer.
Spelunking in the Midwest exposes the patient to bat guano. The chronic respiratory symptoms combined with palatal ulcers are highly specific for disseminated histoplasmosis.
Histoplasmosis is endemic to the Ohio River valley, and mucosal ulcerations are a classic differentiating physical exam finding for disseminated disease.
3
Analyze the exposure history for the avian rescue volunteer.
Recent acquisition of sick cockatiels followed by high fever, severe headache, and dry cough is the classic presentation of psittacosis.
Chlamydia psittaci is an obligate intracellular bacterium transmitted via inhalation of dried avian excrement from infected birds.
4
Analyze the occupational history and exam findings for the older male.
Decades of work with insulation and brakes indicates asbestos exposure. Insidious dyspnea, clubbing, and crackles reflect fibrotic lung disease (asbestosis).
Unlike the acute or subacute infectious etiologies, pneumoconioses develop over decades and present with chronic, progressive structural lung changes.

Key Concept

Correlating specific occupational, recreational, and environmental exposure histories with their classic clinical presentations to guide appropriate diagnostic workup.
Estimated Time:2m 0s
Question 143Question →

Match each patient's clinical presentation and specific risk factors with the most appropriate next step in diagnostic imaging.

Click a left item, then click its matching right item

Items

A 68-year-old man with a non-MRI-compatible cardiac pacemaker who presents with new-onset bilateral lower extremity weakness, hyperreflexia, a sensory level at T10, and urinary retention.
A 32-year-old woman at 14 weeks gestation who presents with fever, leukocytosis, and severe right lower quadrant abdominal pain; an initial graded compression ultrasound is non-diagnostic due to overlying bowel gas.
A 45-year-old man with Marfan syndrome who presents with sudden-onset, severe, tearing chest pain radiating to his back; his medical records document a history of anaphylactic shock following administration of iodinated contrast media.
A 72-year-old man who recently experienced a transient ischemic attack (TIA) and requires evaluation of the extracranial cervical vasculature; he has severe claustrophobia and an estimated glomerular filtration rate (eGFR) of 15 mL/min/1.73 m².

Matches

Show answer & explanation

Answer

1. Spinal cord compression with pacemaker -> CT myelography of the spine; 2. Suspected appendicitis in pregnancy after non-diagnostic US -> MRI of the abdomen and pelvis without contrast; 3. Suspected aortic dissection with contrast allergy -> Transesophageal echocardiography (TEE); 4. Carotid evaluation with low eGFR and claustrophobia -> Duplex ultrasonography of the carotid arteries.
Each correct pairing successfully navigates patient-specific contraindications to standard imaging modalities. CT myelography circumvents the pacemaker contraindication for MRI. MRI abdomen without contrast avoids fetal radiation when ultrasound is inconclusive. TEE rapidly assesses the aorta without triggering an iodine allergy. Duplex ultrasound safely evaluates carotids in a claustrophobic patient with severe renal failure.

Step-by-Step Solution

1
Analyze the first presentation: spinal cord compression syndrome in a patient with a non-MRI-compatible pacemaker.
Identified the need to evaluate the spinal canal while avoiding the standard first-line MRI due to absolute contraindication.
MRI magnetic fields can disrupt pacemakers, necessitating an alternative like CT myelography.
2
Evaluate the second presentation: pregnant patient with suspected appendicitis and a non-diagnostic ultrasound.
Selected MRI without contrast as the next best step to avoid fetal radiation exposure.
CT carries a risk of teratogenicity and childhood malignancy, making non-contrast MRI the preferred second-line modality in pregnancy.
3
Assess the third presentation: Marfan syndrome patient with suspected aortic dissection and severe iodine allergy.
Chose TEE instead of the standard CTA.
CTA requires iodinated contrast, which could trigger a life-threatening anaphylactic reaction, making TEE the safest rapid diagnostic tool.
4
Review the fourth presentation: TIA patient needing carotid evaluation with an eGFR of 15 and severe claustrophobia.
Selected Duplex ultrasonography over CTA or MRA.
CTA risks contrast nephropathy, while MRA is limited by claustrophobia and the risk of gadolinium-induced nephrogenic systemic fibrosis. Ultrasound is safe and effective.

Key Concept

Selecting alternative diagnostic imaging modalities when first-line studies are contraindicated by patient-specific factors such as implants, pregnancy, allergies, or renal impairment.
Estimated Time:1m 30s
Question 144Question →

Match each patient's clinical presentation to the single most appropriate initial or definitive imaging modality.

Click a left item, then click its matching right item

Items

A 32-year-old female at 28 weeks gestation presenting with sudden-onset pleuritic chest pain, tachypnea, a normal lower extremity ultrasound, and a normal chest radiograph.
A 58-year-old male with longstanding diabetes mellitus evaluated in the clinic for a chronic plantar ulcer that probes to the bone; initial plain radiographs show no abnormalities.
A 70-year-old male with a 50-pack-year smoking history undergoing evaluation for recent onset of painless gross hematuria.
A 24-year-old male presenting with progressively worsening headache and confusion two hours after sustaining a direct blow to the temporal region.

Matches

Show answer & explanation

Answer

Patient 1 matches with V/Q scan, Patient 2 matches with MRI of the foot, Patient 3 matches with CT of the abdomen and pelvis, and Patient 4 matches with Non-contrast CT of the head.
Each clinical scenario requires a specific imaging modality optimized for the suspected pathology and patient characteristics. A V/Q scan is optimal for pregnant patients with suspected PE and a normal CXR to reduce breast radiation. MRI is the gold standard for osteomyelitis. Multiphasic CT (CT urography) is the test of choice for high-risk gross hematuria to evaluate for urothelial and renal cancers. Non-contrast head CT provides rapid diagnosis of acute intracranial hemorrhage in trauma.

Step-by-Step Solution

1
Evaluate the pregnant patient with suspected pulmonary embolism.
Select V/Q scan.
When the chest X-ray is normal, V/Q scanning is preferred over CT pulmonary angiography to reduce radiation exposure to maternal breast tissue.
2
Evaluate the diabetic patient with a deep foot ulcer and normal X-rays.
Select MRI of the foot.
MRI provides the highest sensitivity for detecting osteomyelitis and differentiating it from soft tissue infection.
3
Evaluate the elderly smoker with gross hematuria.
Select CT of the abdomen and pelvis with and without contrast.
This multiphasic protocol (CT urography) optimally visualizes both the renal parenchyma and the urothelial tract for masses.
4
Evaluate the young male with acute head trauma.
Select non-contrast CT of the head.
Non-contrast CT is rapid and highly sensitive for detecting acute blood, such as an epidural hematoma.

Key Concept

Selection of appropriate imaging modalities based on suspected clinical diagnosis, patient characteristics, and evidence-based diagnostic guidelines.
Question 145Question →

Evaluate the following complex clinical presentations and match each patient with the most appropriate next imaging or diagnostic study, taking into consideration their specific comorbidities and absolute or relative contraindications.

Click a left item, then click its matching right item

Items

A 67-year-old male presenting with acute, tearing interscapular pain and diaphoresis. His blood pressure is 85/50 mmHg and heart rate is 120/min. His estimated glomerular filtration rate is 18 mL/min/1.73m².
A 54-year-old female with progressive bilateral lower extremity weakness, a distinct sensory level at T10, and urinary retention. She has a history of severe Parkinson disease treated with a non-MRI-compatible deep brain stimulator.
A 28-year-old female at 8 weeks gestation with sudden-onset pleuritic chest pain and dyspnea. Her chest radiograph is normal, and bilateral lower extremity compression ultrasonography reveals no deep vein thrombosis.
A 45-year-old male with recurrent right upper quadrant pain and normal liver biochemistries. A prior abdominal ultrasound was inconclusive due to body habitus. He has a documented history of severe anaphylaxis to iodinated contrast media.

Matches

Show answer & explanation

Answer

The correct pairings are: the hemodynamically unstable patient with suspected aortic dissection requires transesophageal echocardiography; the patient with a deep brain stimulator requires CT myelography; the pregnant patient with a normal chest X-ray requires a V/Q scan; and the patient with an iodine allergy requires magnetic resonance cholangiopancreatography.
Each correct match pairs the patient's specific clinical presentation with an imaging modality that circumvents their unique contraindications, such as hemodynamic instability, implanted metal devices, pregnancy, or severe contrast allergies.

Step-by-Step Solution

1
Evaluate the hemodynamically unstable patient with suspected aortic dissection.
Identify that the patient requires bedside diagnostic imaging.
The patient is too unstable for transport to the CT scanner, and his severe renal impairment makes iodinated contrast highly risky. TEE is the safest and most effective choice.
2
Evaluate the patient with suspected spinal cord compression.
Identify the absolute contraindication to magnetic resonance imaging.
The presence of a non-MRI-compatible deep brain stimulator precludes MRI, necessitating CT myelography as the definitive alternative study to visualize the spinal canal.
3
Determine the optimal pulmonary embolism imaging for the pregnant patient.
Select V/Q scan over CT pulmonary angiography.
In pregnant patients with a normal chest radiograph, a V/Q scan delivers significantly less radiation to the maternal breast tissue while maintaining high diagnostic accuracy for pulmonary embolism.
4
Select imaging for suspected complicated biliary colic with a severe contrast allergy.
Choose magnetic resonance cholangiopancreatography (MRCP).
With an inconclusive initial ultrasound, further cross-sectional imaging is needed. The iodinated contrast allergy precludes CT, making MRCP the best non-invasive modality to evaluate the biliary tree.

Key Concept

Selecting appropriate imaging modalities by integrating clinical stability, diagnostic capabilities, and absolute or relative contraindications (e.g., pregnancy, incompatible implants, contrast allergies).
Question 146Question →

Match the following clinical quality and safety scenarios with the most appropriate quality improvement (QI) tool or methodology.

Click a left item, then click its matching right item

Items

Proactively identifying potential vulnerabilities in a newly designed patient handoff protocol before it goes live.
Retroactively investigating a sentinel event where a retained surgical sponge was discovered after an operation.
Iteratively testing a small, rapid change to a discharge process on a single hospital unit before widespread implementation.
Analyzing the frequency of different causes of medication errors to visually determine which minority of causes produce the majority of errors.

Matches

Show answer & explanation

Answer

Proactive vulnerability identification matches with FMEA; retroactive sentinel event investigation matches with RCA; iterative small tests of change match with PDSA; and prioritizing causes by frequency matches with Pareto chart analysis.
Each quality improvement tool serves a distinct purpose. FMEA is proactive risk management. RCA is retrospective error analysis. PDSA is for iterative testing of interventions. Pareto charts are for data visualization to prioritize improvement efforts based on the 80/20 rule.

Step-by-Step Solution

1
Analyze the first scenario regarding proactively identifying vulnerabilities before a protocol goes live.
This describes Failure Mode and Effects Analysis (FMEA).
FMEA is specifically designed for forward-looking risk assessment to prevent errors before implementation.
2
Analyze the second scenario involving retroactive investigation of a sentinel event.
This describes Root Cause Analysis (RCA).
RCA looks backward after an incident to determine system vulnerabilities that allowed the error to occur.
3
Analyze the third scenario about iteratively testing small changes on a single unit.
This describes the Plan-Do-Study-Act (PDSA) cycle.
PDSA cycles are the standard methodology for rapid, iterative tests of change on a small scale.
4
Analyze the fourth scenario concerning determining which minority of causes produce the majority of errors.
This describes a Pareto chart analysis.
Pareto charts apply the 80/20 principle to help prioritize quality improvement efforts by focusing on the most significant factors.

Key Concept

Quality Improvement Models and Methodologies
Question 147Question →

A nephrologist is reviewing renal biopsy reports for four different adult patients who presented with various nephritic or nephrotic syndromes. To establish the correct diagnosis, match each specific glomerular disease with its most pathognomonic histological, immunofluorescence, or ultrastructural finding on renal biopsy.

Click a left item, then click its matching right item

Items

IgA nephropathy (Berger disease)
Membranous nephropathy
Goodpasture disease (anti-GBM disease)
Post-streptococcal glomerulonephritis

Matches

Show answer & explanation

Answer

IgA nephropathy matches with mesangial IgA deposition; Membranous nephropathy matches with 'spike and dome' appearance; Goodpasture disease matches with linear IgG deposition; Post-streptococcal glomerulonephritis matches with subepithelial 'humps'.
Establishing a definitive diagnosis for primary glomerular diseases relies heavily on identifying distinct biopsy findings. Goodpasture disease is unique for its linear immunofluorescence pattern caused by anti-GBM antibodies. Immune complex diseases produce granular patterns, but their specific location and appearance differentiate them: IgA nephropathy shows mesangial deposits, membranous nephropathy causes a subepithelial 'spike and dome' pattern due to basement membrane remodeling, and post-streptococcal glomerulonephritis presents with large subepithelial 'humps'.

Step-by-Step Solution

1
Differentiate the primary patterns of immunofluorescence presented in the biopsy findings.
Identified one linear immunofluorescence pattern and one granular mesangial immunofluorescence pattern.
Immunofluorescence patterns are critical for distinguishing between direct autoantibody binding (linear) and immune complex deposition (granular).
2
Correlate the linear immunofluorescence pattern with its corresponding etiology.
Matched linear IgG deposition with Goodpasture (anti-GBM) disease.
Anti-GBM antibodies uniformly target the basement membrane, resulting in a smooth, linear pattern.
3
Correlate the mesangial IgA immunofluorescence pattern with its corresponding etiology.
Matched granular mesangial IgA and C3 deposition with IgA nephropathy.
IgA nephropathy is defined by the localized deposition of IgA complexes within the glomerular mesangium.
4
Analyze the remaining ultrastructural findings on electron and light microscopy to match the remaining conditions.
Matched 'spike and dome' with membranous nephropathy and subepithelial 'humps' with post-streptococcal glomerulonephritis.
Subepithelial humps are classic for post-infectious etiologies, whereas the spike and dome pattern indicates basement membrane reaction to subepithelial deposits seen in membranous nephropathy.

Key Concept

Histopathological and Immunofluorescence Diagnosis of Glomerular Diseases
Question 148Question →

Match each classic radiographic imaging finding (sign) with its most likely associated clinical condition.

Click a left item, then click its matching right item

Items

"Thumbprint sign" on a lateral soft-tissue neck radiograph
"Steeple sign" on an anteroposterior (AP) neck radiograph
"Apple-core lesion" on a barium enema study
"Bamboo spine" appearance on an anteroposterior lumbar radiograph

Matches

Show answer & explanation

Answer

Thumbprint sign matches with Epiglottitis; Steeple sign matches with Croup; Apple-core lesion matches with Colorectal adenocarcinoma; and Bamboo spine matches with Ankylosing spondylitis.
Each classic imaging sign directly corresponds to a distinct anatomical alteration caused by its respective underlying pathophysiology. Correctly recognizing these patterns ensures rapid, accurate diagnosis in clinical practice.

Step-by-Step Solution

1
Analyze the pediatric airway imaging signs.
The thumbprint sign denotes supraglottic swelling (epiglottitis), while the steeple sign denotes subglottic swelling (croup).
Differentiation of upper airway distress is rapidly aided by evaluating the specific anatomic location of edema on neck films.
2
Analyze the gastrointestinal and musculoskeletal imaging signs.
An apple-core lesion reflects circumferential luminal narrowing (colon cancer), and a bamboo spine reflects continuous syndesmophyte formation (ankylosing spondylitis).
These represent classic, high-yield radiologic appearances of structural disease progression that guide immediate diagnostic and therapeutic next steps.

Key Concept

Recognizing pathognomonic imaging signs for classic medical conditions
Question 149Question →

Match each distinct pathognomonic neuroimaging finding on computed tomography (CT) or magnetic resonance imaging (MRI) with its corresponding acute neurologic condition.

Click a left item, then click its matching right item

Items

Lentiform (biconvex) hyperdense collection strictly bounded by cranial suture lines on non-contrast head CT
Crescent-shaped hyperdense collection that crosses cranial suture lines but is limited by dural reflections on non-contrast head CT
Hyperdense appearance of the middle cerebral artery (MCA) combined with loss of the insular ribbon on non-contrast head CT
Central hypodensity surrounded by contrast enhancement within the superior sagittal sinus ('empty delta sign') on contrast-enhanced CT or MR venography

Matches

Show answer & explanation

Answer

The correct matches pair specific neuroimaging signs with their diagnostic pathologies: lentiform hyperdensity with epidural hematoma, crescent-shaped hyperdensity with subdural hematoma, hyperdense MCA sign with acute ischemic stroke, and empty delta sign with cerebral venous sinus thrombosis.
Each imaging sign is highly specific for its respective acute neurologic condition based on the anatomical compartments involved, the source of bleeding or thrombus, and the physiological tissue response to ischemia.

Step-by-Step Solution

1
Analyze the first imaging finding: a lentiform hemorrhage bounded by sutures.
Matches with epidural hematoma.
Arterial pressure strips the dura from the skull, but the bleeding cannot pass the tight dural attachments at the cranial sutures, forming a biconvex shape.
2
Analyze the second imaging finding: a crescentic hemorrhage crossing sutures.
Matches with subdural hematoma.
Venous bleeding in the subdural space is not restricted by cranial sutures and spreads widely over the hemisphere, taking on a crescent shape.
3
Analyze the third imaging finding: hyperdense MCA with loss of insular ribbon.
Matches with acute ischemic stroke.
These are classic early CT signs of an acute infarction in the MCA territory before overt parenchymal hypodensity develops.
4
Analyze the fourth imaging finding: empty delta sign on contrast imaging.
Matches with cerebral venous sinus thrombosis.
The filling defect represents the central non-enhancing thrombus, while the surrounding dural venous collaterals enhance brightly.

Key Concept

Interpreting pathognomonic neuroimaging findings for acute neurological emergencies
Question 150Question →

Match each of the following synoptic pathology descriptions and immunohistochemical profiles from lymph node or bone marrow biopsies to the most appropriate definitive hematolymphoid diagnosis.

Click a left item, then click its matching right item

Items

Diffuse architectural effacement by medium-sized lymphoid cells with frequent mitoses and interspersed tingible-body macrophages; positive for CD10 and BCL6, negative for BCL2.
Nodular growth pattern composed of a mixture of centrocytes and centroblasts; positive for CD10, BCL6, and strongly positive for BCL2.
Diffuse infiltrate of small-to-medium lymphoid cells with irregular nuclear contours; positive for CD5 and Cyclin D1, negative for CD23.
Nodular and interstitial infiltrates of small, mature-appearing lymphocytes; positive for CD5 and CD23, negative for Cyclin D1.
Rare, large, binucleated cells with prominent eosinophilic nucleoli surrounded by a dense mixed inflammatory infiltrate; positive for CD15 and CD30, negative for CD45 and CD20.

Matches

Show answer & explanation

Answer

Burkitt lymphoma matches the BCL2-negative starry sky pattern. Follicular lymphoma matches the BCL2-positive nodular pattern. Mantle cell lymphoma matches the CD5+/CD23-/Cyclin D1+ profile. CLL/SLL matches the CD5+/CD23+ profile. Classic Hodgkin lymphoma matches the CD15+/CD30+/CD45- binucleated cells.
Definitive hematolymphoid diagnoses require integrating cellular morphology, growth patterns, and specific immunophenotypes. Burkitt lymphoma presents with a 'starry sky' pattern and is definitively BCL2 negative. Follicular lymphoma classically expresses BCL2 due to its defining t(14;18) translocation. Mantle cell lymphoma is driven by a t(11;14) translocation leading to Cyclin D1 overexpression, demonstrating a CD5+/CD23- profile. CLL/SLL uniquely co-expresses CD5 and CD23. Finally, Classic Hodgkin lymphoma is characterized by Reed-Sternberg cells that express CD15 and CD30 but lack the common leukocyte antigen CD45.

Step-by-Step Solution

1
Analyze the first profile featuring a high mitotic rate and a lack of BCL2 expression.
Identified as Burkitt lymphoma.
Burkitt lymphoma is a rapidly dividing germinal center tumor (CD10+) that uniquely lacks BCL2, which differentiates it from follicular lymphoma.
2
Evaluate the nodular architecture exhibiting CD10, BCL6, and BCL2 positivity.
Identified as Follicular lymphoma.
The strong aberrant BCL2 expression in a nodular follicular pattern is pathognomonic for the t(14;18) translocation seen in Follicular lymphoma.
3
Examine the two CD5-positive profiles to accurately differentiate Mantle cell lymphoma from CLL/SLL.
The CD5+/CD23-/Cyclin D1+ profile maps to Mantle cell lymphoma; the CD5+/CD23+ profile maps to CLL/SLL.
CD23 and Cyclin D1 are the most reliable immunophenotypic markers to distinguish these two common CD5+ B-cell lymphomas.
4
Identify the large cells lacking CD45 and CD20 but expressing CD15 and CD30.
Identified as Classic Hodgkin lymphoma.
Classic Reed-Sternberg cells typically lose standard B-cell markers and pan-leukocyte markers while aberrantly expressing CD15 and CD30 within a reactive inflammatory background.

Key Concept

Accurate interpretation of lymph node and bone marrow pathology relies on synthesizing morphological features with specific immunohistochemical panels to differentiate overlapping hematolymphoid malignancies.
Question 151Question →

A multidisciplinary sarcoma tumor board is reviewing the pathology of several young adult patients presenting with deep soft tissue and bone masses. To establish the definitive diagnosis and guide neoadjuvant therapy, the pathologist correlates the microscopic morphology and immunohistochemical (IHC) profiles with their defining molecular signatures. Match the following complex histopathologic and immunohistochemical biopsy descriptions with their corresponding definitive diagnoses and characteristic chromosomal translocations.

Click a left item, then click its matching right item

Items

A deep thigh mass biopsy reveals a dual population of primitive spindle cells and glandular-like epithelial structures. The tumor cells show strong nuclear expression of TLE1 and focal positivity for cytokeratin.
An intramuscular calf lesion biopsy demonstrates prominent arborizing, delicate capillaries in an abundant basophilic, myxoid stroma, containing scattered cells with multiple cytoplasmic lipid vacuoles.
A deep aponeurotic mass in the foot shows nested aggregates of uniform, pale-staining cells separated by fibrous bands. Immunohistochemistry is strongly positive for S100 protein and HMB-45, but lacks BRAF mutations.
A rapidly enlarging extremity mass biopsy exhibits uniform, primitive round cells arranged in nests separated by thick fibrous bands. The cells in the center of the nests are discohesive. IHC shows strong nuclear myogenin expression.
A diaphyseal biopsy of a permeative bony lesion demonstrates dense sheets of uniform cells with scant cytoplasm, round nuclei, and indistinct nucleoli. Tumor cells show strong, diffuse membranous staining for MIC2 (CD99).

Matches

Show answer & explanation

Answer

The correct matches integrate the distinct morphologic descriptions and IHC markers with their pathognomonic translocations: The TLE1+ biphasic tumor is Synovial Sarcoma; the myxoid tumor with arborizing capillaries is Myxoid Liposarcoma; the deep S100/HMB-45+ mass is Clear Cell Sarcoma; the myogenin+ discohesive round cell tumor is Alveolar Rhabdomyosarcoma; and the CD99+ small round blue cell bone tumor is Ewing Sarcoma.
Each histopathologic description contains pathognomonic keywords directly linked to a specific sarcoma subtype and its defining cytogenetic abnormality. TLE1 and biphasic histology point to synovial sarcoma (t(X;18)). Chicken-wire vasculature with lipoblasts indicates myxoid liposarcoma (t(12;16)). Melanocytic markers in a deep mass without BRAF mutations denote clear cell sarcoma (t(12;22)). Pseudo-alveolar architecture with myogenin designates alveolar rhabdomyosarcoma (t(2;13)). Membranous CD99 in a bony small round cell tumor signifies Ewing sarcoma (t(11;22)).

Step-by-Step Solution

1
Analyze the thigh mass biopsy showing a dual population of cells and TLE1 positivity.
Identified as Synovial Sarcoma.
TLE1 is a highly sensitive and specific immunohistochemical marker for synovial sarcoma, which characteristically shows biphasic differentiation and harbors the t(X;18) translocation.
2
Analyze the calf mass biopsy showing arborizing delicate capillaries and lipoblasts in a myxoid stroma.
Identified as Myxoid Liposarcoma.
The 'chicken-wire' vascular pattern in a mucinous background is the classic histopathologic hallmark of myxoid liposarcoma, which is driven by the t(12;16) translocation.
3
Analyze the deep aponeurotic foot mass showing melanocytic markers (S100+, HMB-45+) without a BRAF mutation.
Identified as Clear Cell Sarcoma of soft tissue.
Clear cell sarcoma is phenotypically identical to melanoma but is genetically distinct, characterized by the t(12;22) EWSR1-ATF1 fusion rather than BRAF V600E mutations.
4
Analyze the extremity mass showing nested round cells with central discohesion and myogenin positivity.
Identified as Alveolar Rhabdomyosarcoma.
Central loss of cohesion creating pseudo-alveolar spaces combined with skeletal muscle differentiation markers defines alveolar rhabdomyosarcoma, carrying the t(2;13) translocation.
5
Analyze the diaphyseal bone lesion showing uniform small round cells with membranous CD99 expression.
Identified as Ewing Sarcoma.
Strong, diffuse membranous staining for CD99 (MIC2) in a monotonous small round blue cell tumor of the bone is highly characteristic of Ewing sarcoma, confirmed by t(11;22).

Key Concept

Integrating histomorphology, specific immunohistochemical staining patterns, and pathognomonic chromosomal translocations is essential for establishing the definitive diagnosis of soft tissue and bone sarcomas.
Question 152Question →

Match each classic clinical vignette with the most appropriate initial imaging modality to order.

Click a left item, then click its matching right item

Items

A 2424-year-old pregnant woman (1414 weeks gestation) presents with acute right lower quadrant abdominal pain, fever, and leukocytosis.
A 6565-year-old hemodynamically stable man presents with sudden, severe 'tearing' chest pain radiating to his interscapular region.
A 5050-year-old woman presents with postprandial right upper quadrant abdominal pain, fever, and inspiratory arrest on deep palpation.
A 7070-year-old man presents to the emergency department 4545 minutes after the sudden onset of left-sided hemiparesis and dysarthria.

Matches

Show answer & explanation

Answer

The correct matches align each clinical presentation with its standard-of-care initial imaging: pelvic ultrasound for the pregnant patient with right lower quadrant pain, CT angiography for suspected aortic dissection, right upper quadrant ultrasound for suspected acute cholecystitis, and non-contrast CT of the head for suspected acute stroke.
Each clinical presentation is a classic scenario requiring a specific initial imaging modality based on standard evidence-based guidelines. Ultrasound is appropriately utilized for pregnant patients to avoid radiation and for evaluating the biliary tree. CT angiography is the standard for stable aortic dissection, and a rapid non-contrast head CT is essential to rule out hemorrhage in acute stroke.

Step-by-Step Solution

1
Analyze the 2424-year-old pregnant patient's presentation.
Acute appendicitis is suspected, and imaging must avoid ionizing radiation.
To ensure fetal safety while effectively establishing a diagnosis.
2
Evaluate the hemodynamically stable patient with tearing chest pain.
Aortic dissection is highly suspected, requiring rapid visualization of the aorta.
To confirm the diagnosis and determine the extent of the dissection before surgical or medical intervention.
3
Assess the patient with right upper quadrant pain and a positive Murphy sign.
Acute cholecystitis is the primary differential, requiring visualization of the gallbladder and biliary tree.
Ultrasound is the most sensitive, specific, and non-invasive initial test for gallbladder pathology.
4
Review the presentation of the patient with sudden-onset hemiparesis.
An acute ischemic or hemorrhagic stroke is occurring.
A non-contrast CT is required immediately to rule out intracranial hemorrhage before considering thrombolytic therapy.

Key Concept

Selecting the most appropriate initial imaging study based on suspected diagnosis, patient stability, and patient-specific safety factors (e.g., pregnancy).
Question 153Question →

Match each clinical presentation of acute or subacute pulmonary disease with the most likely predominant pattern seen on high-resolution computed tomography (HRCT) of the chest.

Click a left item, then click its matching right item

Items

A 62-year-old man with a 6-month history of progressive exertional dyspnea, dry cough, and fine bilateral basal inspiratory crackles (velcro-like) on examination.
A 45-year-old pigeon breeder presenting with subacute progressive dyspnea, cough, and weight loss over the past 4 months.
A 55-year-old woman with a persistent cough and dyspnea for 6 weeks, who failed to improve after multiple courses of antibiotics for presumed community-acquired pneumonia.
A 35-year-old previously healthy man with progressive dyspnea on exertion and production of abundant, milky, proteinaceous sputum.

Matches

Show answer & explanation

Answer

The 62-year-old man matches with subpleural honeycombing (UIP pattern). The pigeon breeder matches with centrilobular nodules and air trapping (HP). The woman failing antibiotics matches with peripheral consolidation and the reverse halo sign (COP). The young man with milky sputum matches with the crazy-paving pattern (PAP).
Each clinical presentation describes a distinct interstitial or alveolar lung disease that has a hallmark HRCT pattern. Idiopathic Pulmonary Fibrosis corresponds to the UIP pattern (honeycombing and traction bronchiectasis). Hypersensitivity pneumonitis presents with centrilobular nodules and air trapping. Cryptogenic Organizing Pneumonia presents with peripheral consolidations or the reverse halo sign. Pulmonary Alveolar Proteinosis classically shows a crazy-paving pattern.

Step-by-Step Solution

1
Analyze the first clinical vignette to identify the underlying syndrome.
The 62-year-old man with velcro-like crackles and exertional dyspnea has Idiopathic Pulmonary Fibrosis (IPF).
Age, chronic symptoms, and specific physical exam findings are highly suggestive of IPF.
2
Correlate IPF with its pathognomonic imaging pattern.
Matched with the Usual Interstitial Pneumonia (UIP) pattern, which involves honeycombing and traction bronchiectasis.
UIP is the radiologic hallmark required to diagnose IPF without a surgical lung biopsy.
3
Analyze the second vignette and find its imaging correlate.
The pigeon breeder has Hypersensitivity Pneumonitis, matching with centrilobular nodules and mosaic attenuation.
Antigen exposure leads to an inflammatory response in bronchioles and alveoli, visible as nodules and air trapping on expiratory HRCT imaging.
4
Analyze the third vignette and correlate with imaging.
The woman failing antibiotics has Cryptogenic Organizing Pneumonia (COP), matching with peripheral consolidations and the reverse halo sign.
COP frequently mimics infectious pneumonia clinically but does not respond to antibiotics, showing organizing intraluminal plugs radiographically.
5
Analyze the fourth vignette and match its imaging pattern.
The young man with milky sputum has Pulmonary Alveolar Proteinosis (PAP), matching with the crazy-paving pattern.
Accumulation of surfactant in alveoli creates ground-glass opacities with thickened septa, typical of PAP.

Key Concept

Recognizing the characteristic High-Resolution Computed Tomography (HRCT) patterns of specific interstitial and alveolar lung diseases is essential for accurate, non-invasive diagnosis and subsequent management.
Question 154Question →

Match each patient's clinical presentation with the most appropriate next step in diagnostic imaging.

Click a left item, then click its matching right item

Items

A 28-year-old man presenting with a newly discovered painless, firm testicular nodule.
A 42-year-old woman presenting with fever, severe right upper quadrant abdominal pain, and a positive Murphy sign.
A 65-year-old man presenting with acute shortness of breath, tachycardia, and a high clinical probability of pulmonary embolism.
A 35-year-old non-pregnant woman presenting with fever, severe right lower quadrant abdominal pain, and leukocytosis.

Matches

Show answer & explanation

Answer

The correct matches pair suspected testicular cancer with scrotal ultrasound, acute cholecystitis with right upper quadrant abdominal ultrasound, pulmonary embolism with computed tomography pulmonary angiography, and acute appendicitis with computed tomography of the abdomen and pelvis.
Each matched pair represents the standard-of-care initial diagnostic imaging test for the suspected condition, optimizing diagnostic accuracy while minimizing unnecessary risks such as radiation or contrast exposure when not indicated.

Step-by-Step Solution

1
Analyze the first clinical scenario of a painless testicular mass in a young man.
Identify the need to differentiate solid from cystic lesions.
Scrotal ultrasound is the standard initial step before any invasive urologic intervention.
2
Analyze the second scenario involving right upper quadrant pain and fever.
Identify acute cholecystitis as the most likely diagnosis.
Right upper quadrant ultrasound is highly sensitive, lacks radiation, and is the gold standard initial test for biliary tract disease.
3
Analyze the third scenario indicating a high probability of pulmonary embolism.
Select CT pulmonary angiography.
CTPA provides definitive visualization of pulmonary vasculature to confirm or rule out the embolus.
4
Analyze the fourth scenario of right lower quadrant pain and fever in a non-pregnant adult.
Select CT of the abdomen and pelvis with contrast.
CT is the most accurate imaging modality for diagnosing acute appendicitis in this demographic.

Key Concept

Selecting the guideline-indicated initial diagnostic imaging modality based on specific clinical presentations.
Question 155Question →

A physician is reviewing several skin biopsy reports from different patients evaluated in an outpatient dermatology clinic. To finalize the clinical assessments, identify the correct condition for each microscopic finding. Match each classic histopathological description to its most accurate definitive diagnosis.

Click a left item, then click its matching right item

Items

Basal cell carcinoma
Squamous cell carcinoma
Melanoma
Psoriasis
Bullous pemphigoid

Matches

Show answer & explanation

Answer

Basal cell carcinoma matches with peripheral palisading and clefting. Squamous cell carcinoma matches with intercellular bridges and keratin pearls. Melanoma matches with asymmetric proliferation and pagetoid spread. Psoriasis matches with elongated rete ridges and neutrophils in the stratum corneum. Bullous pemphigoid matches with subepidermal blisters and an eosinophil-rich infiltrate.
Definitive diagnosis in dermatology heavily relies on correlating clinical morphology with microscopic biopsy findings. Basal cell carcinoma uniquely features basaloid nests with peripheral palisading. Squamous cell carcinoma shows invasive atypical keratinocytes with keratin pearl formation. Melanoma is identified by asymmetric, atypical melanocytic proliferation with upward epidermal (pagetoid) spread. Psoriasis displays uniform epidermal hyperplasia (elongated rete ridges) and collections of neutrophils. Bullous pemphigoid is characterized by full-thickness epidermal separation (subepidermal blister) packed with eosinophils.

Step-by-Step Solution

1
Analyze the first biopsy description for key cellular architectural patterns.
Identify 'peripheral palisading' and 'clefting' as the pathognomonic features of basal cell carcinoma.
These specific architectural features distinguish basal cell carcinoma from other skin neoplasms.
2
Evaluate the descriptions highlighting keratinocytes versus melanocytes.
Keratin pearls indicate squamous cell carcinoma, while pagetoid spread of pigment-producing cells indicates melanoma.
Cell lineage specific markers (keratinization vs. melanin/pagetoid spread) differentiate the major types of skin malignancies.
3
Differentiate between the inflammatory skin condition descriptions.
Elongated rete ridges match the chronic inflammatory plaque state of psoriasis, whereas a subepidermal cleavage plane matches the autoimmune blistering mechanism of bullous pemphigoid.
Understanding the mechanism of disease (epidermal hyperproliferation vs. basement membrane antibody attack) directly correlates with the histologic findings.

Key Concept

Histopathological hallmarks of common dermatologic diseases and cutaneous malignancies.
Question 156Question →

Match each interstitial and diffuse parenchymal lung disease with its most characteristic high-resolution computed tomography (HRCT) imaging pattern.

Click a left item, then click its matching right item

Items

Idiopathic pulmonary fibrosis
Idiopathic nonspecific interstitial pneumonia
Cryptogenic organizing pneumonia
Fibrotic hypersensitivity pneumonitis
Pulmonary alveolar proteinosis

Matches

Show answer & explanation

Answer

Idiopathic pulmonary fibrosis matches with basal/subpleural honeycombing and reticular opacities. Idiopathic nonspecific interstitial pneumonia matches with basilar ground-glass opacities and subpleural sparing. Cryptogenic organizing pneumonia matches with patchy peripheral consolidation and the reverse halo sign. Fibrotic hypersensitivity pneumonitis matches with upper/mid-lung fibrosis, centrilobular micronodules, and mosaic attenuation. Pulmonary alveolar proteinosis matches with the crazy-paving pattern.
The correct pairings rely on recognizing the standardized radiologic criteria for interstitial lung diseases. Idiopathic pulmonary fibrosis requires a Usual Interstitial Pneumonia (UIP) pattern, identified by honeycombing and subpleural/basal predominance. NSIP lacks honeycombing, features uniform ground-glass opacities, and often spares the immediate subpleura. Fibrotic hypersensitivity pneumonitis is distinguished by its 'three-density pattern' (headcheese sign) and upper-lung predominance. COP presents with consolidative changes, often migrating, with the reverse halo sign. PAP is the classic cause of the extensive crazy-paving pattern without fibrosis.

Step-by-Step Solution

1
Analyze the imaging description for characteristic spatial distribution (e.g., upper vs. lower lobe, subpleural vs. peribronchovascular).
Lower lobe predominance aligns with idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP), while upper lobe points toward fibrotic hypersensitivity pneumonitis (FHP).
Spatial distribution serves as a primary discriminator in HRCT interpretation for diffuse parenchymal lung diseases.
2
Identify pathognomonic radiological signs within each description to confirm the diagnosis.
Honeycombing confirms IPF; subpleural sparing confirms NSIP; a reverse halo sign confirms cryptogenic organizing pneumonia (COP); mosaic attenuation with centrilobular nodules confirms FHP; crazy-paving confirms pulmonary alveolar proteinosis (PAP).
Specific radiological signs accurately link the descriptive text to the underlying histopathological patterns, averting the need for surgical biopsy in typical cases.

Key Concept

High-Resolution Computed Tomography (HRCT) patterns are highly specific for differentiating various diffuse parenchymal and interstitial lung diseases based on spatial distribution and pathognomonic parenchymal signs.
Estimated Time:2m 0s
Question 157Question →

A central neuropathology laboratory is reviewing surgical biopsy specimens from four different patients who presented with progressive neurologic deficits and primary intracranial masses on magnetic resonance imaging (MRI). Match each distinct histopathologic, immunohistochemical, and molecular profile with the most likely definitive pathologic diagnosis.

Click a left item, then click its matching right item

Items

Highly cellular proliferation of small, round, hyperchromatic cells forming Homer Wright rosettes; cytogenetic analysis reveals the presence of isochromosome 17q.
Whorls of spindled cells accompanied by abundant calcified psammoma bodies; immunohistochemistry demonstrates strong, diffuse positivity for somatostatin receptor 2A (SSTR2a) and epithelial membrane antigen (EMA).
GFAP-positive neoplasm demonstrating prominent perivascular pseudorosettes and true rosettes; tumor cells exhibit characteristic dot-like cytoplasmic EMA positivity.
Infiltrating astrocytic proliferation featuring pseudopalisading necrosis and microvascular proliferation; molecular testing confirms an IDH-wildtype profile and EGFR amplification.

Matches

Show answer & explanation

Answer

1 matches with Medulloblastoma; 2 matches with Meningioma; 3 matches with Ependymoma; 4 matches with Glioblastoma.
Each tumor profile contains pathognomonic features that secure the diagnosis according to WHO CNS tumor classification criteria. Medulloblastomas feature small round blue cells with Homer Wright rosettes and frequently isochromosome 17q. Meningiomas present with meningothelial whorls, psammoma bodies, and SSTR2a positivity. Ependymomas demonstrate perivascular pseudorosettes with unique dot-like EMA positivity. Glioblastomas are defined by pseudopalisading necrosis, microvascular proliferation, and an IDH-wildtype profile.

Step-by-Step Solution

1
Analyze the first biopsy profile noting the small round blue cells, Homer Wright rosettes, and isochromosome 17q.
Identify the profile as Medulloblastoma.
These are the classic morphologic and genetic hallmarks of this pediatric embryonal tumor.
2
Evaluate the second profile featuring meningothelial whorls, psammoma bodies, and SSTR2a positivity.
Identify the profile as Meningioma.
SSTR2a and EMA positivity paired with whorled architecture definitively diagnoses a meningioma.
3
Assess the third profile showing GFAP-positivity, perivascular pseudorosettes, and dot-like EMA positivity.
Identify the profile as Ependymoma.
While both ependymomas and some other gliomas express GFAP, the true rosettes and dot-like EMA positivity are highly specific for ependymoma.
4
Review the fourth profile characterized by pseudopalisading necrosis, microvascular proliferation, and IDH-wildtype status.
Identify the profile as Glioblastoma.
The combination of necrosis, microvascular proliferation, and IDH-wildtype status confirms a high-grade astrocytoma (glioblastoma).

Key Concept

Definitive diagnosis of central nervous system tumors requires integrating microscopic architectural patterns (e.g., specific rosette types, whorls, necrosis) with targeted immunohistochemical markers (e.g., EMA, GFAP, SSTR2a) and molecular/cytogenetic profiles (e.g., IDH status, isochromosome 17q).
Estimated Time:1m 30s
Question 158Question →

Evaluate the following acute clinical presentations. For each patient scenario, identify the single most appropriate diagnostic imaging study to order.

Click a left item, then click its matching right item

Items

A 24-year-old female with sudden-onset right lower quadrant pain, vaginal spotting, and a positive urine pregnancy test.
A 45-year-old male with severe, colicky left flank pain radiating to the groin and microscopic hematuria.
A 68-year-old male with atrial fibrillation who developed sudden, severe periumbilical pain that is out of proportion to the benign abdominal exam findings.
A 32-year-old female at 28 weeks gestation with suspected acute appendicitis following an inconclusive initial right lower quadrant sonogram.

Matches

Show answer & explanation

Answer

The correct matches are: The pregnant patient with spotting requires a pelvic ultrasound. The patient with suspected nephrolithiasis requires a non-contrast CT. The patient with suspected mesenteric ischemia requires CT angiography. The pregnant patient with suspected appendicitis and an equivocal ultrasound requires an MRI without contrast.
Each imaging modality is chosen to maximize diagnostic yield while minimizing patient risk. Pelvic ultrasound is safe and sensitive for early pregnancy complications. Non-contrast CT best identifies renal stones. CT angiography visualizes vascular occlusions in suspected ischemia. MRI avoids radiation in pregnancy when an initial ultrasound is nondiagnostic.

Step-by-Step Solution

1
Analyze the first scenario (young female, positive pregnancy test, abdominal pain).
Identify high risk for ectopic pregnancy.
Requires radiation-free imaging to immediately identify intrauterine versus extrauterine gestation.
2
Analyze the second scenario (colicky flank pain, hematuria).
Identify classic presentation of nephrolithiasis.
Requires high-sensitivity imaging to detect calcified stones without obscuration by intravenous contrast.
3
Analyze the third scenario (atrial fibrillation, pain out of proportion to exam).
Identify high suspicion for acute mesenteric ischemia.
Requires visualization of the mesenteric vasculature using arterial phase contrast.
4
Analyze the fourth scenario (pregnant, suspected appendicitis, equivocal ultrasound).
Identify need for definitive cross-sectional imaging without ionizing radiation.
MRI is safe in pregnancy and provides excellent soft-tissue contrast to visualize the appendix when ultrasound fails.

Key Concept

Selecting the most appropriate imaging modality requires integrating the suspected pathology with patient-specific factors, such as pregnancy status, radiation risk, and the need for vascular visualization.
Estimated Time:1m 30s
Question 159Question →

Match each classic radiographic finding with the most likely rheumatologic or joint disorder it represents.

Click a left item, then click its matching right item

Items

"Punched-out" periarticular erosions with overhanging cortical edges and relative preservation of joint space
Asymmetric joint space narrowing, subchondral bone sclerosis, and marginal osteophyte formation
Symmetric joint space narrowing, periarticular osteopenia, and marginal bone erosions
Linear or punctate radiodense deposits within the articular cartilage and menisci (chondrocalcinosis)

Matches

Show answer & explanation

Answer

Properly pair the imaging findings to their distinct pathologies: punched-out erosions with Gout; asymmetric wear and osteophytes with Osteoarthritis; symmetric wear and osteopenia with Rheumatoid arthritis; and chondrocalcinosis with Calcium pyrophosphate deposition disease.
The correct pairings align the pathognomonic radiographic descriptions with their established diseases: osteoarthritis features mechanical asymmetric narrowing and osteophytes; rheumatoid arthritis features symmetric inflammatory narrowing and osteopenia; gout features distinct erosions with overhanging edges; and CPPD features diagnostic chondrocalcinosis.

Step-by-Step Solution

1
Analyze the pattern of joint space involvement and bone density.
Identify whether the narrowing is symmetric (suggesting an inflammatory process) or asymmetric (suggesting a mechanical process), and note any osteopenia.
This primary distinction differentiates mechanical osteoarthritis from systemic inflammatory conditions like rheumatoid arthritis.
2
Identify specific pathognomonic imaging markers for distinct crystal arthropathies.
Note the presence of 'punched-out' erosions with overhanging edges or distinct cartilage calcification.
These findings directly point to gout or calcium pyrophosphate deposition disease, respectively, rather than general wear or systemic inflammation.
3
Match the identified radiographic constellations to the correct clinical diagnoses.
The final pairings are successfully completed based on these classic imaging criteria.
Accurate interpretation of these specific imaging findings is essential for differentiating joint disorders and initiating the correct long-term management.

Key Concept

Radiographic differentiation of common arthropathies based on joint space narrowing patterns, erosive features, and bone density changes.
Question 160Question →

Match each acute clinical presentation with the most appropriate and urgent next diagnostic step.

Click a left item, then click its matching right item

Items

A 62-year-old man with a history of hypertension presenting with sudden-onset "tearing" chest pain radiating to the back and asymmetric arm blood pressures.
A 24-year-old woman presenting with severe right lower quadrant abdominal pain, nausea, and a positive urine pregnancy test.
A 55-year-old man with known cirrhosis presenting with new-onset fever, diffuse abdominal pain, worsening ascites, and mild encephalopathy.
A 68-year-old woman presenting to the emergency department with acute right-sided hemiparesis and global aphasia that began 45 minutes ago.
A 35-year-old intravenous drug user with fever, a new holosystolic cardiac murmur, and suspected infective endocarditis who has not yet received any antimicrobial treatment.

Matches

Show answer & explanation

Answer

1 matches with CTA of the chest; 2 matches with Transvaginal ultrasonography; 3 matches with Diagnostic paracentesis; 4 matches with Non-contrast CT of the head; 5 matches with Multiple sets of peripheral blood cultures.
Each clinical presentation is matched with its most critical initial diagnostic step based on standardized medical guidelines, focusing on rapid stabilization, avoidance of harm, and accurate diagnosis.

Step-by-Step Solution

1
Evaluate the 62-year-old man for acute aortic dissection based on his tearing chest pain and asymmetric blood pressures.
Computed tomography angiography (CTA) of the chest is selected.
CTA provides rapid, definitive imaging to identify the intimal flap and classify the dissection.
2
Assess the 24-year-old pregnant woman with right lower quadrant pain.
Transvaginal ultrasonography is selected.
It is the safest imaging modality to visualize an ectopic pregnancy while avoiding radiation exposure to the fetus.
3
Analyze the 55-year-old man with cirrhosis, fever, and worsening ascites for spontaneous bacterial peritonitis (SBP).
Diagnostic paracentesis is selected.
Ascitic fluid analysis is necessary to confirm SBP (absolute neutrophil count > 250/mm³) before initiating antibiotics.
4
Review the presentation of the 68-year-old woman with acute stroke symptoms onset 45 minutes ago.
Non-contrast CT of the head is selected.
A non-contrast CT rapidly rules out intracranial hemorrhage, which is required before any thrombolytic therapy can be considered.
5
Examine the case of the 35-year-old intravenous drug user with signs of infective endocarditis.
Multiple sets of peripheral blood cultures are selected.
Cultures must be drawn prior to starting empiric antibiotics to ensure accurate pathogen identification and susceptibility testing.

Key Concept

Appropriate test sequencing in acute clinical scenarios requires prioritizing tests that rapidly identify life-threatening conditions (e.g., non-contrast CT for stroke, CTA for aortic dissection) or tests that must precede therapeutic interventions (e.g., blood cultures before antibiotics).
Estimated Time:2m 0s
PreviousPage 8 / 43Next