Abstract
A 22-year-old female was admitted with symptom of anal bleeding. No abnormalities were found on physical examination, except for a small polypoid lesion on the posterior wall of the rectal ampulla, about 6cm from the anus. The mass was revealed by radiological and endoscopic study ; it was evenly covered by an almost yellowish mucosa, and a shallow depression was noted at the mass' apex. Biopsy specimen showed histologically the mass to be carcinoidic, and the same diagnosis was reached under electron microscopy. The tumor, measuring 1.0×1.0×9 in width, was excised from the anus. By serially cutting the surface of the specimen, it was revealed that invasion was limited to the mucosa. The method of surgical removal of carcinoid rectal tumors must be determined according to the degree of invasion ; thus, knowledge about the depth of invasion is extremely important before surgery.
