Solitary Extramedullary Plasmacytoma of the Liver without Systemic Monoclonal Gammopathy

Extramedullary plasmacytoma of the liver is a very rare tumor. Although a few cases of extramedullary plasmacytoma of the liver have been reported, we could not find any report on truly localized extramedullary plasmacytoma of the liver in the literature. The patient was a 63-yr-old man who exhibited a solitary liver mass on dynamic computed tomography and magnetic resonance imaging. Histologically, the tumor was composed of mature plasma cells with mild atypia. Immunohistochemistry demonstrated monoclonal IgG and Kappa light chain expression. Bone marrow examination revealed no abnormalities. There was no evidence of a monoclonal protein in the serum and urine, lytic bone lesions, anemia, renal insufficiency, and hypercalcemia. The patient was treated with 5,000 cGy of radiotherapy, and the tumor disappeared 6 months after treatment.