Cap Polyposis

An 18-year-old man presented with sensation of anal mass and repeated episodes of rectal bleeding for 6 months, which he initially attributed to hemorrhoids. The patient had no history of chronic constipation or other medical history. Physical examination was unremarkable, apart from a palpable mass on digital rectal examination. All laboratory investigations were negative including H. pylori. On colonoscopy, multiple rough and uneven protuberances, with an erythematous surface and a yellow-white coating, can be observed from the upper edge of the anal canal up to 8 cm above it (Fig. 1). Biopsy of the lesions showed elongated, hyperplastic-appearing glands with a characteristic overlying cap formed by an inflammatory exudate composed of mucus, fibrin, and leukocytes (Fig. 2), which were consistent with cap polyposis. Subsequently, the polys were removed with endoscopic mucosal resection (EMR). During the following 6 months, the previously noted complaints improved significantly. A repeat colonoscopy was performed and the remaining polyps were resected simultaneously. Fig. 2Histopathology revealing elongated, hyperplastic-appearing glands with a characteristic overlying cap formed by an inflammatory exudate composed of mucus, fibrin, and leukocytes (Original magnification: left 10×, middle 40×, right 100×). View Large Image Figure Viewer Download Hi-res image