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. J. Clin. Lab. Anal. 13:112–115, 1999. © 1999 Wiley-Liss, Inc.