Systemic amyloid arthropathy associated with multiple myeloma

This is the first report of an autopsy case of systemic amyloid arthropathy associated with multiple myeloma in Japan. The patient was a 72-year-old male who had been suffering from multiple myeloma (IgA-lambda) with extensive arthropathy of the systemic joints. Autopsy examination revealed severe deposit of amyloid in the articular cavities of the systemic joints showing a feature of amyloidoma. Furthermore, numerous amyloid deposits were found in the wall of small blood vessels in the major organs. In the bone marrow, there were many atypical plasma cells and foamy cells both showing positive reaction for IgA and lambda light chain. No such atypical cells were observed in the other organs except for the bone marrow.