[Actinomycosis of the sigmoid as obstructive space-occupying lesion of the pelvis. A case report].

Abdominal actinomycosis is a rare chronic infectious disease, which may mimic abdominal cancer, inflammatory bowel disease or diverticulitis. We report the case of a 46-year-old women with a large bowel obstruction caused by extensive abdominal actinomycosis. Colon contrast examination revealed a stenosis in the sigmoid colon, while abdominal ultrasound showed a stenosis of the left ureter with left hydronephrosis. Preoperative presumptive diagnosis was a carcinoma of the sigmoid colon. She required emergency surgery, which involved both resection and colostomy. As in most cases reported in the literature, diagnosis was made postoperatively. Pathological examination following the sigmoid colon resection surprisingly revealed an actinomycosis. This case illustrates that consideration of actinomycosis in women with bowel obstruction and prolonged use of an intrauterine device could help to improve the preoperative diagnosis of this rare disease.