[Testicular involvement in IgD multiple myeloma]

A 65-year-old man was admitted to our hospital in September 1997 because of back pain and renal dysfunction. He was diagnosed as having multiple myeloma due to the presence of IgD lambda monoclonal gammopathy and diffuse infiltration of plasma cells in the bone marrow. The patient achieved a partial response to DMVM-IFN-alpha combination therapy. His condition worsened in December 1998, but was ameliorated by VAD therapy. The patient's left testis became enlarged in December 1999, and an orchiectomy was performed. The normal testicular cells had been entirely displaced by myeloma cells comprising typical plasma cells and large lymphoid cells. Pleural, mediastinal, spinal, and right testicular involvement with myeloma subsequently developed. Despite attempts to treat the patient with more than one type of combination therapy, his condition worsened progressively, and he died in June 2000. Reports of IgD myeloma with testicular involvement are rare. The histopathology of our patient's resected testis, i.e. the two myeloma cell-plasmacytoid and lymphoid cell components showing differential immunostaining, was unique.