2018 Volume 60 Issue 4 Pages 1010-1016
Colonoscopy was performed on a 45-year-old Japanese woman who was positive for fecal occult blood. A Ⅱa-like polyp, approximately 5 mm in diameter, was found in the hepatic flexure. Its surface was reddish and smooth, without erosion. Endoscopic mucosal resection of the polyp was performed for diagnosis and treatment. Microscopically, inflammatory cell infiltration was observed on the epithelial surface and an increased number of fibroblastic cells was noted in the lamina propria. Immunohistochemical studies showed that the fibroblastic cells were positive for vimentin, GLUT-1 and claudin-1, but not for desmin, c-kit, CD34, α-smooth muscle actin, S-100 or epithelial membrane antigen. The Ki-67 labeling index was less than １%. These results suggested that the lesion in the hepatic flexure was a benign fibroblastic polyp (perineurioma). Benign fibroblastic polyps (perineuriomas) of the colon are rare, and there have been no reports of cases with the endoscopic and histopathological features observed in our case. Herein, we report our experience of a case of a benign fibroblastic polyp (perineurioma) in the hepatic flexure.
