A 55-year-old man has scaly erythematous skin patches progressing to plaques over 4 years, now with circulating atypical lymphocytes showing deeply convoluted, cerebriform nuclei. Flow cytometry shows CD3+, CD4+, CD7-negative, CD26-negative cells. What is the diagnosis?
- A Adult T-cell leukemia/lymphoma
- B Mycosis fungoides with Sezary syndrome ✓
- C Angioimmunoblastic T-cell lymphoma
- D T-cell prolymphocytic leukemia
Correct answer: B. Mycosis fungoides with Sezary syndrome
Explanation
Mycosis fungoides is a cutaneous T-cell lymphoma of skin-homing CD4-positive cells; leukemic dissemination with cerebriform Sezary cells, erythroderma, and lymphadenopathy defines the Sezary syndrome variant. Loss of pan-T markers CD7 and CD26 supports malignancy. Adult T-cell leukemia/lymphoma is HTLV-1 associated with flower-like multilobated nuclei and hypercalcemia, while angioimmunoblastic lymphoma presents with generalized lymphadenopathy and systemic symptoms, not indolent cutaneous plaques.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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