2015 Volume 57 Issue 4 Pages 1197-1202
Colonoscopy was performed on a 60-year-old Japanese woman positive for fecal occult blood. A sessile IIa-like polyp, approximately 8 mm in diameter, was found in the sigmoid colon. Its surface was smooth, without erosion or bleeding. Endoscopic mucosal resection of the polyp was carried out for diagnosis and treatment. Microscopically, the epithelial surface of the polyp was intact and without erosion or hyperplastic epithelial cells, but increased numbers of fibroblastic cells were noted in the lamina propria. Fibroblastic cells showed diffusely expressed vimentin and focally weak CD34 expression, but did not express CD117 (c-kit), CD34, α-smooth muscle actin (αSMA) or S100. These results suggested the lesion in the sigmoid colon was a benign fibroblastic polyp.
