Abstract
Extramedullary plasmacytoma of the stomach is an extremely rare disease. Only 30 cases of primary gastricplasmacytoma have been reported in Japan and about 70 cases in the USA and European countries. This is a reportof a case of gastric plasmacytoma producing K-light chain immunoglobulin. A 61-year-old woman visited ourhospital complaining of abdominal discomfort. Laboratory studies revealed no abnormalities. X-ray and endoscopicexamination of the upper gastrointestinal tract revealed elevated cauliflower-like lesions on both anterior andposterior walls. Immunohistochemical studies of a specimen obtained by polypectomy revealed a plasmacytomaproducing K-light chain immunoglobulin. A total gastrectomy with lymphadenectomy (R3) was performed. Grossexamination the resected stomach showed nodular lesions resembling cerebral convolutions. Histologicalexamination revealed that the two main elevated lesions in both posterior and anterior walls were invaded byplasma cells like neoplastic cells producing K-light chain immunogloblin monoclonally. The tumor cells hadinvaded the mucosal layer.
