Abstract
A 62-year-old woman with IgA-λ type monoclonal gammopathy had been followed up since January 1988. In March 1991, multiple myeloma (IgA-λ) was diagnosed on the basis of bone marrow biopsy findings and increased serum IgA levels. She was treated intermittently with melphalan and prednisolone over a perioa of about 6 years, but was eventually admitted due to renal dysfunction, hypercalcemia, increased serum IgA and the formation of subcutaneous masses. During chemotherapy she underwent emergency surgery for obturative ileus. Histological examination of the resected tissues revealed invasion of myeloma cells into the small intestine and peritoneum. Despite continued chemotherapy, the patient's soft tissue masses enlarged, and new lesions appeared in other organs. In the terminal stage, lower serum IgA levels were observed despite an increase in Bence-Jones protein levels in urine. The patient died five months after admission. An autopsy found infiltration by atypical myeloma cells in multiple organs. An immunohistochemical examination revealed an increase in λ-light chain positive cells relative to the number of α-heavy chain positive cells. The terminal course was considered to be representative of aggressive phase multiple myeloma. The case was rare in that the patient's ileus was caused by invasion of myeloma cells into the small intestine.