Intramucosal Colon Cancer Developing in an Inverted Hyperplastic Polyp

Inverted hyperplastic polyps (IHPs) of the colon are unusual variant of exophytic hyperplastic polyps that are characterized by epithelial displacement or inversion of the epithelium into the submucosa. To date, only a few cases of IHPs associated with adenoma or adenocarcinoma have been reported. However, due to the rarity of these polyps, their malignant potential is poorly understood. A 56-year-old man was referred to Uijeongbu St. Mary’s Hospital due to a positive fecal occult-blood test during a routine health check-up. The patient had a medical history of surgery for intestinal perforation and hypertension. On admission, physical examination revealed no abnormal findings and all laboratory examination were within normal range. We performed colonoscopy for further evaluation. The colo-