[Transition to aggressive phase in a multiple myeloma patient with IgH/CCND1 translocation and diffuse osteosclerotic lesions].

A 71-year-old woman had been diagnosed as having osteosclerotic myeloma (BJP-λ type) three years prior to the current presentation, based on tumor biopsy from the forehead showing plasmacytoma with systemic osteosclerotic lesions. At 71 years of age, she underwent transverse colectomy for a tumor in the hepatic flexure of the large intestine, and it was diagnosed as IgH/CCND-1-positive plasmacytoma of the large intestine. Although serum vascular endothelial cell growth factor (VEGF) was not elevated, the plasmacytoma was largely positive for VEGF staining. She subsequently experienced transformation to aggressive myeloma over a short period of time. Osteosclerotic myeloma is a rare disease that accounts for less than 3% of all myelomas, and requires differentiation from POEMS syndrome. In this case, peripheral nerve symptoms, which are necessary for the diagnosis of POEMS syndrome, were not confirmed. Thus, this case was diagnosed as having osteosclerotic myeloma. By contrast, abnormal IgH/CCND-1 is confirmed in 15% of patients with myeloma, and 25% of those with POEMS syndrome. While it is unclear whether this genetic abnormality is involved in the development of an osteosclerotic lesion, it is expected that data from patients with osteosclerotic myeloma and POEMS syndrome will be accumulated in the future, allowing clarification of the relationship between the genetic abnormality and osteosclerosis.