Colonic Perforation Secondary to Entamoeba Histolytica Infection: A Case Report

Background: Fulminant amebic colitis is an uncommon, life-threatening manifestation of Entamoeba histolytica infection. Because its clinical and radiologic features overlap with appendicitis, diverticulitis, inflammatory bowel disease, ischemia, and colorectal malignancy, diagnosis may be delayed until surgery or histopathologic examination. Case presentation: A 42-year-old man without relevant medical history developed sudden colicky and pressure-like right iliac fossa pain. Symptoms partially improved after unspecified analgesic and antimicrobial treatment, but recurred 15 days later with nausea and vomiting. On 1 November 2022, he was evaluated for an acute abdomen. Computed tomography suggested acute appendiceal disease and showed sigmoid diverticular and inflammatory-appearing mesenteric lymph nodes. Emergency exploratory laparotomy revealed a small amount of purulent intraperitoneal fluid and a pelvic inflammatory mass involving the sigmoid colon and cecum, associated with a 12 × 8 × 2 cm indurated lesion above the rectosigmoid junction. Sigmoidectomy, appendectomy, and end-to-end colorectal anastomosis were performed. Histopathology demonstrated intense acute inflammation with chronic granulomatous inflammation, multinucleated foreign-body-type giant cells, and microscopic structures compatible with amoebae. The patient completed seven days of postoperative inpatient observation, graduating later without complications. Conclusion: Amebic colitis should remain in the differential diagnosis of a colonic inflammatory mass or perforation in endemic settings. Early recognition, parasite-directed therapy, and prompt source control are essential. Histopathologic examination may establish the diagnosis when the preoperative presentation is nonspecific.