A 68-year-old man with incidentally detected mild lymphocytosis and splenomegaly undergoes peripheral smear review. The abnormal cells are small mature lymphocytes with short polar villi concentrated at one pole of the cell. Flow cytometry shows CD20+, surface Ig+, CD5-negative, CD10-negative, CD23-negative, annexin A1-negative. What is the diagnosis?

• A Splenic marginal zone lymphoma ✓
• B Chronic lymphocytic leukemia
• C Hairy cell leukemia
• D Follicular lymphoma

Explanation

Villous lymphocytes with polar (not circumferential) projections, splenomegaly, and a CD5-negative, CD10-negative, CD23-negative mature B phenotype define splenic marginal zone lymphoma. CLL would be CD5+ and CD23+ with smooth cells. Hairy cell leukemia has circumferential hair-like projections and is TRAP positive and annexin A1 positive. Follicular lymphoma expresses CD10 and shows t(14;18).

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.