Hand mirror cell lymphoid leukemia in adults. A distinct clinicopathologic syndrome. Case report and literature review.

Hand mirror cell (HMC) lymphoid leukemia is an unusual variant of acute lymphocytic leukemia (ALL) in which the bone marrow lymphoblasts manifest distinctive hand mirror morphologic features. Reported here is a 66-year-old woman with HMC lymphoid leukemia whose clinical course was characterized by 12 months of initial disease stability while she was receiving no chemotherapy; a prompt response to cyclophosphamide, vincristine, and prednisone therapy once instituted; and a hyperleukocytic episode (leukocyte count 607,000/mm3), which resulted in her death after 22 months of disease. This patient and 13 other reported adults (15 years and older) with HMC lymphoid leukemia (greater than 40% bone marrow HMC) are reviewed. HMC lymphoid leukemia appears to differ from typical adult ALL in that it has a female predominance, a relatively indolent early clinical course that lasts 1 year or longer, and it manifests the possibility of survival for 1 or 2 years despite the failure to achieve a complete remission with chemotherapy. Phenotypically, the HMC leukemic cells from all adults evaluated were null cells, Ia-positive, TdT-positive, and stained positively with acid phosphates, which suggests that HMC lymphoid leukemia is a variant of non-T, non-B-ALL. HMC lymphoid leukemia in adults appears to be a distinctive clinicopathologic entity.