Mantle cell leukemia, prolymphocytoid type: a rarely described form

Leukemic manifestations of mantle cell lymphoma are seen in a minority of cases, usually associated with extensive tumor. Usually the neoplastic cells in the peripheral blood resemble mantle cells with a mature chromatin pattern and irregular nuclear contours, or less frequently with a more "blastic" chromatin pattern. A prolymphocytic leukemia with t(11;14)(q13;q32) has previously been reported; however, a complete flow cytometric immunophenotypic profile was lacking. Mantle cell leukemia, prolymphocytoid type with complete flow cytometric data has not previously been described and is the purpose of this report. We report such a case in a 90 year-old female who presented with an elevated white blood cell count. The diagnosis was based on flow cytometric immunophenotyping and the cytomorphology of the peripheral blood combined with cyclin D1 immunohistochemical staining of the bone marrow. We describe our findings and her clinical course in order to heighten awareness of this previously rarely described entity.