WBR0785

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian)]]
Exam Type	USMLE Step 1
Main Category	Pathophysiology
Sub Category	Oncology
Prompt	[[Prompt::A 69-year-old man is being worked up for recent onset renal insufficiency. As part of his work-up, his nephrologist orders a blood smear with a photomicrograph presented below. Which of the following conditions can explain the patient’s findings? ]]
Answer A	Hairy cell leukemia
Answer A Explanation	Hairy cell leukemia is not associated with rouleaux formation on peripheral smear. Typical findings include lymphocytes with irregular hair-like borders.
Answer B	Chronic lymphocytic leukemia
Answer B Explanation	CLL is not associated with rouleaux formation on peripheral smear.
Answer C	Hemolytic uremic syndrome
Answer C Explanation	HUS is not associated with rouleaux formation on peripheral smear. Schistocytes are classically found in patients with HUS.
Answer D	Disseminated intravascular coagulopathy
Answer D Explanation	DIC is not associated with rouleaux formation on peripheral smear. Schistocytes can also be found in DIC.
Answer E	Multiple myeloma
Answer E Explanation	MM is usually associated with rouleaux formation on peripheral smear due to the associated hypergammaglobulinemia.
Right Answer	E
Explanation	[[Explanation::Multiple myeloma is a malignant plasma cell proliferation clinically characterized by anemia, bone pain, and renal insufficiency. Diagnosis is usually supported by multiple tests including serum and urine assays for monoclonal protein M spike, light chain assays, serum beta-2-microglobulin, bone marrow biopsy, and skeletal imaging. A classical finding of multiple myeloma on peripheral smear is rouleaux formation of red blood cells due to the aggregation with serum paraproteins. Other diseases with elevated serum proteins can exhibit rouleaux formation although MM is a classical example tested on board examinations. Educational Objective: The increase in serum paraproteins in multiple myeloma leads to RBC rouleaux formation on peripheral smear. References: San miguel JF, Gutiérrez NC, Mateo G, Orfao A. Conventional diagnostics in multiple myeloma. Eur J Cancer. 2006;42(11):1510-9.]]
Approved	Yes
Keyword	Multiple myeloma, Rouleaux, MM, Hypergammaglobulinemia
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