Clinical Gastroenterology and Hepatology Image Challenge: A 71-year-old woman presented with sensation of anal mass, episodes of rectal bleeding and 2 kg weight loss in the previous year. She was previously diagnosed of hemorrhoids treated with warm sitz baths and antihemorrhoidal cream. Rectal examination revealed a pedunculated hard mass. Colonoscopy showed an irregular, ulcerated, blackish, hard and friable mass in the confluence of the lower rectum anal canal (figure A). Histologic examination demonstrated malignant intraepithelial proliferation of melanocytes (figure B). Magnetic resonance imaging revealed a mass in the anorectal junction, occupying 50% of the circumference with no signs of obstruction (figure C). Laparoscopic abdominoperineal resection (figure D) was performed, presenting a favorable postoperative course with discharge on the fifth day.
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