Inflammatory fibroid polyp (IFP) is an inflammatory tumor of unknown origin arising in the gastrointes-tinal tract. It commonly appears in the stomach and small intestine, and rarely in the large intestine. Only 19 cases of IFP arisen in the large intestine have been reported in the Japanese literature.
We report a case of IFP of the transverse colon with some bibliographical comment. A 69-year-old woman was admitted to the hospital because of positive response to the tests for fecal occult blood. Barium enema study and colonoscopic examination revealed a polyp in the transverse colon with the size of 3×3.5×7.0cm. A partial excision of the transverse colon was performed. Histological examination showed an enormous proliferation in the connective tissues and infiltration of eosinophilic leukocytes in the submucosa. There were thick-walled vessels surrounded by the proliferative fibromuscular fibers, resulting in an onion skin appearance. Pathologically, the lesion was diagnosed as IFP.