Chronic lymphocytic leukemia (CLL) peripheral smear and bone marrow aspirate

Peripheral blood smear (A) and bone marrow aspirate (B) from a patient with chronic lymphocytic leukemia. The peripheral blood smear demonstrates a lymphocytosis. The leukemic cells are small, mature-appearing lymphocytes with a dense nucleus, partially aggregated (clumped) chromatin, and without discernible nucleoli (arrows). There is a narrow border of clear to slightly basophilic cytoplasm. The field includes some segmented neutrophils (arrowhead) and a nucleated red blood cell (dashed arrow). The bone marrow aspirate demonstrates an increased percentage of mature-appearing lymphocytes.