A 55-year-old man presents with fatigue, recurrent skin infections, and massive splenomegaly without lymphadenopathy. CBC shows pancytopenia. Bone marrow aspiration yields a dry tap; trephine biopsy shows interstitial infiltrates of cells with abundant cytoplasm and hair-like projections. Tartrate-resistant acid phosphatase staining is positive. Best first-line therapy?

• A Imatinib
• B Splenectomy alone
• C R-CHOP chemotherapy
• D Cladribine ✓

Explanation

Hairy cell leukemia is a clonal D-cell proliferation presenting in middle-aged men with pancytopenia, monocytopenia, massive splenomegaly, dry tap on marrow aspiration, and TRAP-positive cells with hairy cytoplasmic projections. The purine analog cladribine (or pentostatin) induces durable complete remissions in the majority of patients and is first-line. Splenectomy was historical palliation before purine analogs and does not address marrow disease.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.