Large cell variants of CD5(+), CD23(-) B-cell lymphoma/leukemia - Morphologic findings and bone marrow involvement

Context.-Mantle cell lymphoma (MCL), and its leukemic phase, constitute a w ell-studied hematologic malignancy with known overall survival, prognostic indicators, morphologic findings at diagnosis and in bone marrow, and known incidence of the bcl-1 immunoglobulin gene rearrangement. Large cell varia nts of B-cell lymphoma/leukemia with a mantle cell immunophenotype (CD5(+), CD23(-)), including but not limited to blastic MCL, prolymphocytoid MCL, b lastic mantle cell leukemia, and prolymphocytic mantle cell leukemia, are n ot as well characterized. Although blastic MCL is known to be associated wi th a shorter overall survival than conventional MCL, the large cell variant s of B-cell lymphoma/leukemia with a mantle cell immunophenotype have not b een described as fully as conventional MCL. Objective.-The purpose of the present study was to describe the large cell variants of B-cell lymphoma/leukemia with a mantle cell immunophenotype. Design.-Nineteen cases of large cell variants of CD5(+), CD23 B-cell lympho ma/leukemia are reviewed and described in regard to morphology, bone marrow morphological findings, Cyclin D1 immunostaining, and bcl-1 analysis. Clin ical data were not available owing to the varied clinical sources of the sp ecimens. Setting.-Tertiary-care academic institution. Results.-Lymph node involvement in blastic CD5(+), CD23(-) B-cell lymphoma was diffuse (100%) with a nodular component (33%) or focal mantle zone patt ern (10%). Bone marrow involvement in blastic CD5(+), CD23(-) B-cell lympho ma was seen in only 27% of cases and was composed predominantly of small, s lightly irregular lymphocytes. Cyclin D1 was demonstrated in 60% of the 15 cases analyzed and more sensitive in B5-fixed tissue. Bcl-1 (performed in 5 cases) was not detected in the 4 cases of blastic CD5(+), CD23- B-cell lym phoma analyzed and was detected in the case of the prolymphocytoid MCL. Cyc lin D1 was demonstrated in all 4 bcl-1 negative cases and was negative in t he bcl-1 positive prolymphocytoid MCL. Conclusion.-Careful analysis of clinical data, morphology, immunophenotype, Cyclin D1 expression, and molecular analysis are required to differentiate the unusual large cell variants of MCL from other processes.