A 68-year-old man is brought to the emergency department by his daughter due to a 3-day hi… — USMLE Step 2 CK

A $68$ -year-old man is brought to the emergency department by his daughter due to a $3$ -day history of progressively worsening headache, blurred vision, and confusion. He also reports having two episodes of severe epistaxis earlier in the week. Over the past several months, he has experienced fatigue and a $4.5\text{ kg}$ ( $10\text{ lb}$ ) weight loss. His temperature is $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure is $145/85\text{ mm Hg}$ , heart rate is $92/\text{min}$ , and respiratory rate is $16/\text{min}$ . Physical examination reveals bilateral cervical lymphadenopathy. Funduscopic examination shows dilated, tortuous retinal veins with scattered retinal hemorrhages. Neurologic examination shows an oriented but lethargic patient with no focal motor or sensory deficits. Laboratory studies show the following:

Laboratory Test	Result
Hemoglobin	$8.4\text{ g/dL}$
Mean corpuscular volume	$88\text{ fL}$
Leukocytes	$6,200/\text{mm}^3$
Platelets	$145,000/\text{mm}^3$
Calcium	$9.2\text{ mg/dL}$
Creatinine	$1.1\text{ mg/dL}$
Total protein	$10.5\text{ g/dL}$
Albumin	$3.8\text{ g/dL}$

Serum protein electrophoresis demonstrates a prominent monoclonal spike in the gamma-globulin region. Quantitative immunoglobulins reveal a markedly elevated IgM level. Which of the following is the most appropriate next step in management?

Plasma exchangeCevap
B
Packed red blood cell transfusion
C
Intravenous normal saline and furosemide
D
Hemodialysis
E
Intravenous ceftriaxone and vancomycin

Cevap

Plasma exchange

This patient's presentation of an elevated total protein with a large gamma gap, combined with an IgM monoclonal spike and lymphadenopathy, strongly suggests Waldenström macroglobulinemia (WM). The acute onset of headache, blurred vision, confusion, and epistaxis, along with the classic funduscopic finding of dilated, tortuous retinal veins (often described as 'sausage-link' veins), is pathognomonic for hyperviscosity syndrome. Because IgM is a massive pentameric immunoglobulin, extremely high concentrations significantly increase serum viscosity, which leads to sludging of blood in the microcirculation of the brain, eyes, and mucosal surfaces. The most appropriate and urgent next step in management is plasma exchange (plasmapheresis). This procedure rapidly clears the large IgM molecules from the circulation, immediately reversing the hyperviscosity and resolving the acute symptoms. Once the acute crisis is managed, definitive treatment with systemic chemotherapy or targeted therapies can be initiated.

Adım Adım Çözüm

Analyze the clinical and laboratory findings to establish a diagnosis.

The patient has lymphadenopathy, an IgM monoclonal spike, and a large gamma gap (Total protein 10.5 g/dL minus Albumin 3.8 g/dL). This is diagnostic of Waldenström macroglobulinemia.

Differentiating Waldenström macroglobulinemia from Multiple Myeloma is crucial, as the latter typically presents with IgG/IgA spikes, hypercalcemia, and renal failure.

Identify the cause of the patient's acute symptoms.

The combination of headache, confusion, blurred vision, epistaxis, and tortuous retinal veins represents hyperviscosity syndrome.

IgM exists as a large pentamer; at high concentrations, it severely increases blood viscosity, leading to impaired microvascular transit and sludging in the central nervous system and retinal vessels.

Determine the most appropriate immediate intervention.

Select plasma exchange (plasmapheresis) as the next step in management.

Plasma exchange is the definitive acute treatment for hyperviscosity syndrome, as it mechanically removes the excess IgM from the circulation, rapidly resolving the life-threatening symptoms before chemotherapy is initiated.

Anahtar Kavram

The initial management of symptomatic hyperviscosity syndrome in Waldenström macroglobulinemia requires urgent plasma exchange to rapidly reduce serum IgM levels and prevent irreversible neurologic or ischemic complications.

Soru

Cevap

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Anahtar Kavram

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