CD5+ diffuse large b-cell lymphoma mimicking metastatic carcinoma to bone marrow

An 89-year old man with a history of prostatic adenocarcinoma presents with fatigue, mild splenomegaly and lymphadenopathy, and pancytopenia. The bone marrow biopsy was received for consultation from an outside institution. The aspirate smears contain scant, largely acellular particles and scattered grape-like clusters of large atypical cells (A, upper panel). The atypical cells have irregular centrally to eccentrically placed nuclei, relatively fine chromatin, distinct nucleoli and variable amounts of pale blue cytoplasm (A, lower panel). Flow cytometric analysis of the marrow aspirate shows no increased blasts and no atypical myeloid or lymphoid populations.