[Double B-cell malignancies with simultaneous onset]

We encountered a case of a 59-year-old female who simultaneously contracted a non-Hodgkin lymphoma (NHL) and a plasma cell neoplasm. The patient consulted her physician about her abdominal tumor and anemia in March 1999. She was diagnosed as having NHL (follicular center lymphoma, grade I, stage IIA) after an open tumor biopsy, and treated by cycles of CHOP chemotherapy which resulted in complete remission. However, the patient's abdominal tumor appeared again in March 2000 and she was hospitalized at the Ehime University Hospital. A tumor biopsy was performed laparoscopically at that time. Follicular lymphoma (with positive LCA, L-26, and bcl-2 immuno-staining) with the development of retroperitoneal fibrosis was diagnosed again. When a bone marrow puncture was performed because of a condition of monoclonal gammopathy which had continued for two years, a smoldering myeloma was additionally diagnosed. This diagnosis was made after the presence of IgG-lambda M protein when the marrow showed an increase in the number of plasma cells. In a Southern blot analysis which studied the abdominal tumor and the bone marrow cells, each B-cell tumor had a different IgH gene rearrangement pattern. Therefore, this case was diagnosed as an example of the simultaneous existence of two different B-cell tumors. Double cancers in hematological malignancies are very rare and this was thought to be an interesting case.