[A case of solitary myeloma (BJ-lambda) showing marked morphological changes].

The case report here was documented clinically, cytologically and histologically over a period of 5 years. A 49-year-old man was admitted to our hospital in September, 1975 because of a painful lump over the sternum and a diagnosis of solitary well-differentiated plasmocytoma (BJ-lambda) was made. The tumor promptly subsided following chemotherapy. In July, 1980 as it had in June, 1979, the sternal tumor relapsed; morphologically it was a poorly differentiated plasmocytoma. It promptly subsided following the start of chemotherapy and/or radiation therapy. In February, 1981, an abdominal tumor and ascites developed, morphologically it was plasma cell sarcoma composed of giant and bizarre tumor cells of plasma cell origin as demonstrated by immunoelectron microscopy. In April, 1981, the patient died of cachexia. At autopsy, multiple tumor formations consisting of giant and bizarre myeloma cells were found in the abdominal cavity, liver, retroperitoneum, diaphragm, left adrenal gland, mediastinum and lymph nodes. There was no infiltration of myeloma cells into bones other than the sternum.