[Waldenström macroglobulinemia with diffuse large B-cell lymphoma that developed from a different B-cell clone]

A 62-year-old man was given a diagnosis of Waldenström macroglobulinemia (WM) in January 1995. He was treated with melphalan and corticosteroid until January 1996, when he experienced high fever and weight loss. The patient visited a nearby hospital, received a diagnosis of liver abscess, and was referred to our hospital on February 23, 1996. Computed axial tomographic scans demonstrated multiple isodensity masses in the liver, left adrenal region, and right kidney hilum. Needle biopsy specimens of a liver mass revealed infiltration of diffuse large B-cell lymphoma (REAL classification), suggesting that non-Hodgkin's lymphoma supervened WM. Despite multiple cycles of chemotherapy, the lymphoma responded poorly. The patient died of pneumonia and sepsis on May 10, 1996 and an autopsy disclosed broad involvement of liver and spleen with lymphoma. Southern blot analysis of DNA samples obtained from the patient's bone marrow at the time of the initial diagnosis of WM, and later from the needle biopsy specimen of liver mass, displayed different patterns of immunoglobulin heavy chain gene rearrangement. We therefore concluded that in this patient the lymphoma was not a progression of WM, but rather, an independent B-cell malignancy.