Simultaneous expression of CD2 on a B-cell, small lymphocytic neoplasm.

An unusual neoplasm, best classified as a B-cell chronic lymphocytic leukemia on the basis of cytofluorographic, immunohistologic, and gene rearrangement analysis also co-expressed the T-cell associated marker CD2 (sheep erythrocyte receptor), but without other cell markers restricted to T cells. This case was associated with a more aggressive course than typically seen with B-CLL or malignant lymphoma, small lymphocytic type, implying along with previous reports that CD2 expression may serve as a marker of small lymphocytic tumor cell behavior and the ultimate clinical course. Thus, surface phenotypic analysis of these particular hematopoietic neoplasms may serve not only for identification of the malignancy, but could also render prognostic information.