An unusual pedunculated polyp of the transverse colon associated with schistosomiasis

Inhaltsübersicht

We report here a rare case of a pedunculated, inflammatory polyp of the transverse colon associated with schistosomiasis, which was diagnosed and treated by colonoscopy.

A 48-year-old woman presented to the emergency department after an episode of painless bloody stool. She had had a similar episode 2 months previously. Her history revealed no change in appetite and body weight, gastroduodenal ulcers, or hemorrhoids. She was afebrile on admission. The physical examination showed mild epigastric tenderness, but a digital examination showed no remarkable findings. Laboratory data showed white blood count 8.4 × 10⁹/L, alkaline phosphatase 77 U/L, and normal levels of tumor markers such as carcinoembryonic antigen and carbohydrate antigen 19-9. A plain radiograph of the abdomen showed increased bowel gas pattern in the central abdomen. Colonoscopy revealed a pedunculated polyp, about 20 mm in length and 6 mm in diameter, in the transverse colon ([Fig. 1]). As the polyp was thought to be an adenoma, it was removed by endoscopic mucosal resection. Histopathological examination of the specimen revealed calcified schistosomal ova surrounded by prominent eosinophilic infiltrates in the submucosal layer ([Fig. 2]). The patient was treated with praziquantel (20 mg/kg) with progressive clinical resolution of the bloody stool.

Fig. 1 Colonoscopy showing a pedunculated polyp (20 mm long, 6 mm wide) in the transverse colon.

Fig. 2 Histopathological section showing calcified schistosomal ova surrounded by prominent eosinophilic infiltrates in the submucosal layer.

Colonic schistosomiasis is defined as a specific acute or chronic inflammatory reaction to Schistosoma ova, which are deposited mainly in the colorectal mucosa [1]. Worms trapped in the submucosa produce ova that stimulate an intense tissue reaction that further leads to development of polyposis and occasionally pericolic masses [2]. Schistosomal colonic polyps mainly occur in the distal colon in men living in heavily endemic areas and the presenting symptoms are bloody diarrhea, abdominal pain, and rectal bleeding [3]. Although nonspecific, colonoscopy may provide valuable information in the diagnosis of colonic schistosomiasis, such as edematous, congestive mucosa and petechial hemorrhages in patients with acute schistosomal colitis, and a dense vascular mesh with more close-set, flat or elevated, yellow nodules and polyps, and intestinal stricture in patients with chronic schistosomal colitis [4]. To achieve complete symptom relief and prevent complications, colonoscopic polypectomy may be required along with medical therapy [5].

Competing interests: None

Endoscopy_UCTN_Code_CCL_1AD_2AC

Endoscopy_UCTN_Code_CCL_1AD_2AZ

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