Myeloma, Plasmacytoma.

Plasmacytoma amd multiple myeloma are both patterns of bone destruction, produced by an accumulation of plasma cells. The disease occurs in late middle age with a peak incidence at 60 years. Males are more likely to be affected, 2:1. The single mass of plasmacytoma is lytic and expands the bone with thinning of the cortex. The Multiple myeloma is multifocal and primarily medullary, in the bone marrow. There may be cortical erosion or scalloping.

Since the Isotope bone scan does not record an abnormality, unless a reaction to a fracture, plain film surveys remain one way of assessing disease. The biochemistry reveals an accumulation of protein precursors to antibody production, the para-proteins. The accurate indicator of poor prognosis is impairment of renal function.