Blastic mantle cell leukemia: a previously undescribed form.

The leukemic phase of mantle cell lymphoma (mantle cell leukemia) is defined as an absolute lymphocyte count of greater than 4,000/microliter and characterized by the presence of relatively small, slightly irregular lymphocytes in the peripheral blood. Although a variant of mantle cell lymphoma with blastic morphsology exists and has been previously well described, a blastic morphologic variant of mantle cell leukemia has not been described. We report such a case in a 74-year-old male who presented with splenic rupture and an elevated white blood cell (WBC) count. The diagnosis was based on flow cytometric immunophenotyping and the cytomorphology of the peripheral blood.