[Mantle cell lymphoma mimicking chronic lymphocytic leukemia].

A 62-year-old male was admitted to our hospital complaining of dyspnea in March, 2002. He had remarkable bone marrow invasion with a significant number of leukemic cells, anemia and thrombocytopenia. In addition he had generalized lymphadenopathy including a bulky mass in the left cervix. Surface marker analysis of abnormal cells showed CD 5+, 10-, 19+, 20+, 23+, and kappa+, and immunohistochemistry revealed cyclin D1-positive cells. Chromosome analysis showed del(11q). The patient was diagnosed as having mantle cell lymphoma, stage IVB, and received combination chemotherapy. He could not obtain complete remission and died after 29 months. We found it very difficult in this case to make a differential diagnosis between mantle cell lymphoma and chronic lymphocytic leukemia. We report on this case and summarize the problem of the differential diagnosis.