Chronic Lymphocytic Leukemia / Small Lymphocytic Lymphoma
This 60 y/o male presented with generalized lymphadenopathy. A 2.0 cm left supraclavicular lymph node was biopsied. Flow cytometry showed positivity for CD19, CD20, CD5, and CD23 with lambda light chain restriction. CD10 was negative. Photomicrograph shows effacement of the nodal architecture by a diffuse population of monotonous-appearing small lymphocytes.