A 72-year-old man presents with fatigue, weight loss, splenomegaly, and a WBC of 48×10⁹/L. Smear shows predominantly mature small lymphocytes. Flow cytometry shows CD5+, CD19+, CD23+, CD20 dim, FMC7 negative, sIg dim. What is the diagnosis and first-line treatment for symptomatic disease?
- A Mantle cell lymphoma; RCHOP
- B Marginal zone lymphoma; rituximab monotherapy
- C Chronic lymphocytic leukaemia; venetoclax plus obinutuzumab ✓
- D Hairy cell leukaemia; cladribine
Correct answer: C. Chronic lymphocytic leukaemia; venetoclax plus obinutuzumab
Explanation
The immunophenotype CD5+, CD19+, CD23+, CD20 dim, FMC7−, sIg dim with a Matutes score of 4–5 is diagnostic of CLL. For symptomatic elderly patients, the CLL14 trial established venetoclax plus obinutuzumab as a fixed-duration, chemotherapy-free regimen superior to chlorambucil-obinutuzumab in progression-free survival, now a standard first-line option. Mantle cell lymphoma is CD5+ but CD23−, cyclin D1+. Hairy cell leukaemia presents with pancytopenia and hairy cells on smear.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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