This is a small lymphocytic lymphoma (SLL) with typical flow cytometric pattern of positive markers for CD20 and CD5. The latter is a T cell marker that is normally expressed on few B cells. CD19 and CD20 are typicaly B cell markers. Karyotypic abnormalities include deletions of 11q, 13q, and 17p. SLL is often accompanied by findings of chronic lymphocytic leukemia (CLL) in the peripheral blood. SLL/CLL is an indolent, but systemic disease often involving multiple lymph nodes as well as bone marrow, spleen, and liver. Affected persons are typically over the age of 50.
Without additional information, this histologic appearance and flow cytometric pattern could also represent a mantle cell lymphoma. The CD23 marker is usually present with SLL but absent with mantle cell lymphoma. Most mantle cell lymphomas express cyclin D1, and the characteristic karyotypic abnormality is t(11;14). Mantle cell lymphoma is seen after the age of 40 and tends to be diffuse, but has a survival less than half that of SLL.