A case of IgD myeloma presenting as diffuse osteosclerosis.

A case of IgD myeloma accompanied by diffuse osteosclerosis is reported. A trephine biopsy specimen showed only reticulin fibrosis, but histomorphometric analysis of a full thickness transiliac bone biopsy specimen showed increased trabecular bone mass, with no local deposit of tumour. An excess of bone surfaces were covered by osteoid seams, all of which showed active mineralisation, indicating a relative increase in osteoblastic activity; osteoclasis seemed to be unaffected. It is suggested that the cause of the generalised osteosclerosis might be production of an osteoblast stimulating factor by the myeloma cells.