[Multiple myeloma with a mass formation in a pacemaker pocket].

A 74-year-old female was diagnosed as having multiple myeloma in August 1989 and was treated with combined vincristine, melphalan and prednisolone. Subsequently, she was followed followed up in the outpatient clinic using interferon-alpha. On August 6, 1990, she had a transvenous demand pacemaker inserted because of severe atrioventricular block. The pulse generator was placed in a subcutaneous pocket in the left pectoral area. On February 3, 1991, she developed a mass overlying the pulse generator. This tumor was diagnosed as plasmacytoma by histological examinations. A myelogram showed 5.1% plasma cells with 5.5 x 10(4) nucleated cells/microliter. The amounts of serum protein and IgA M protein were 6.8 g/dl and 1.8 g/dl, respectively. The tumor responded to combined chemotherapy, but reenlarged to the initial size 3-4 weeks later. On August 6, 1991, this tumor, including the pulse generator was removed. By October 1991, the patient had systemic subcutaneous tumors and a right maxillary tumor suggesting the aggressive phase. On December 19, 1991, she died due to cardiac failure. In this paper the discussion focussed on the etiopathogenesis of plasmacytoma arising in the region of pulse generator pockets.