[Tumor-forming type IgA (kappa) multiple myeloma developed into polyclonal hyper gamma-globulinemia after M-protein loss].

A 77 year-old female admitted with costal and right clavicular tumors and multiple osteolytic lesions. In January 1983, a diagnosis of mature type plasmacytoma was made based on the histopathological examination of the right clavicular tumor. The amounts of serum protein and IgA (kappa) M-protein were 7.5 g/dl and 2.1 g/dl, respectively. A myelogram revealed 21% of mature plasma cells with 31.3 x 10(4) nucleated cells/microliter. Four months later following a chemotherapy started in March 1983, the tumor size became smaller with undetected M-protein by an immunofixation method. Besides, a serum protein analysis showed 24.6% of gamma-globulin and 1,980 mg/dl of IgG. However, in December 1983, the right clavicular and costal tumors regrew. The second biopsy specimen showed diffuse proliferated plasmablastoid cells which reacted only to anti-kappa antibody. By August 1984, the patient had systemic subcutaneous tumors as well as polyclonal IgG up to 3,356 mg/dl suggesting rapid progression of the disease. A myelogram showed 7.4% of mature plasma cells. In December 1984, the patient died of complicated obstructive ileus due to multiple mesenteric tumor. In this study we discussed on the role of M-protein loss and increased of normal globulin level in a tumor-forming type multiple myeloma.