Extensive soft tissue uptake of 99Tcm methylene diphosphonate in a patient with multiple myeloma.

Bone scintigraphy is not usually performed in multiple myeloma (MM), as marrow deposits characteristically show no tracer uptake. However, metastatic bone disease often mimics MM both clinically and biochemically, resulting in a substantial number of MM patients undergoing bone scintigraphy. Variable appearances in these cases have been reported, ranging from normal to a superscan, the latter a result of massive tracer uptake within bone. Soft tissue uptake has been documented, often when MM is complicated by secondary amyloidosis. This usually results in mainly solid organ uptake of tracer. We report a case of MM where massive soft tissue uptake occurred, primarily within muscles, with very little isotope elsewhere.