[Painful shoulder in the elderly--not always of degenerative nature].

A 81-year-old man suffered, without any preceding trauma, from progressive pain of his left shoulder since 3 weeks. The left upper arm was warm and swollen with a palpable solid mass. Mild normocytic anemia and an increased erythrocyte sedimentation reaction were determined. X-ray showed an osteolytic lesion of left humerus with pathological fracture and involvement of soft tissue. Multiple myeloma was diagnosed from the biopsy of this lesion, detection of paraprotein IgA Kappa in the serum, and a 15-20% plasma cell infiltration of the bone marrow. The patient responded well to radio-therapy and intravenous application of biphosphonates--the fracture healed by conservative therapy. The treating physician--on the basis of clinical experience and by intuition--has to decide considering medical history and clinical findings whether musculoskeletal pain must be investigated further. Diagnosis of multiple myeloma requires monoclonal protein (paraprotein) in the serum or urine, plasma cell infiltration of the bone marrow, and evidence of end-organ damage (anemia, renal insufficiency, bone lesions or hypercalcemia).