Cap polyposis of the colon and rectum: An analysis of endoscopic findings

Background and Study Aims: Because of the rarity of cap polyposis of the co lon and rectum, the endoscopic features of this condition have not been spe cified to date. The aim of this study is to characterize the endoscopic fea tures of cap polyposis. Patients and Methods: The diagnosis of cap polyposis was established by his tologic findings in specimens obtained endoscopically or surgically from fo ur patients. Colonoscopic findings in the four patients were retrospectivel y reviewed. Results: The endoscopic features were divided into semipedunculated type (t hree patients) and flat-topped protruding type (one patient). In the semipe dunculated type, the polyps were characterized by reddish protrusions of va rious configurations with eroded surface in the rectosigmoid colon, In the remaining patient, all the lesions were flat protrusions with a reddish cen tral depression. The polyps of both types became smaller in size and fen er in number at the proximal part of the sigmoid colon. Multiple white specks were observed in the intervening mucosa in all four patients. Conclusions: The prominence of the polyps at the distal part of the colon a nd rectum and multiple white specks in the intervening mucosa seem to be th e additional endoscopic features suggestive of cap polyposis.