A 69-year-old woman presented to the emergency department of our hospital for a painful perineal mass, which had appeared 6 hours before. Her past medical history included chronic constipation, Waldestrom disease, hypothyroidism, and coronary artery disease. The perineal examination showed a nonreducible, edematous, and partially necrotic mass, exteriorized from the anus (Figure A). Abdominal examination was normal. Vital signs were normal. Blood tests showed an inflammatory syndrome with 11 Â 10 9 /L leucocytes and C-reactive protein at 73.9 mg/L. What is the diagnosis and how should we manage it? See the Gastroenterology web site (www. gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.