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.
Humans ; Immunoglobulin G/analysis ; Immunoglobulin kappa-Chains/analysis ; Immunohistochemistry ; Liver Neoplasms/immunology/*pathology/radiotherapy ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Monoclonal Gammopathies, Benign/immunology/pathology ; Plasmacytoma/immunology/*pathology/radiotherapy ; Tomography, X-Ray Computed

OBJECTIVETo evaluate the feasibility and efficacy of radioimmunotherapy with 131 I-labeled humanized anti-HBsAg Fab (131 I-anti-HBsAg Fab) combined with 131 I-labeled anti-nucleus antigen monoclonal antibody chTNT (131 I-chTNT) in nude mice bearing human hepatocellular carcinoma.

METHODSNude mice bearing subcutaneous human hepatocellular carcinoma xenografts were treated by intratumoral injection of 131 I-anti-HBsAg Fab and/or 131 I-chTNT, and the changes in the tumor size and alterations in the radioactivity concentration in the tumor and non-tumor tissues were observed.

RESULTSThe tumor inhibition rate in mice treated with 131 I-anti-HBsAg Fab combined with 131 I-chTNT (73.09%) was significantly higher than that in mice treated with 131 I-anti-HBsAg Fab (47.8%) or 131 I-chTNT (54.26%) alone. Combined treatment also resulted in significantly higher tumor-to-normal radioactivity concentration ratios than the treatment with the single agents.

CONCLUSIONIntratumoral injection with 131 I-labeled monoclonal antibodies can increase the radioactivity concentration in the tumor and enhance the efficacy of the radioimmunotherapy in nude mice bearing human hepatocellular carcinoma.

Animals ; Antibodies, Antinuclear ; immunology ; Antibodies, Monoclonal ; therapeutic use ; Carcinoma, Hepatocellular ; pathology ; radiotherapy ; Cell Line, Tumor ; Hepatitis B Surface Antigens ; immunology ; Humans ; Immunoconjugates ; therapeutic use ; Immunoglobulin Fab Fragments ; immunology ; Iodine Radioisotopes ; therapeutic use ; Liver Neoplasms, Experimental ; pathology ; radiotherapy ; Mice ; Mice, Nude ; Radioimmunotherapy ; methods ; Treatment Outcome ; Xenograft Model Antitumor Assays