Ileo-caecal actinomycosis: report of a case simulating complicated inflammatory bowel disease

Abdominal actinomycosis is a rare infectious disease caused by Actinomyces israelii, a gram-positive anaerobic saprophyte germ that is a normal inhabitant of the upper intestinal tract in humans. Actinomyces israelii rarely cause abdominal infections or actinomycosis. Abdominal actinomysosis is characterised by fistulae and abscesses and may mimic cancer or inflammatory bowel disease. Abdominal actinomycosis is difficult to diagnose preoperatively, and often require surgical removal of the diseased tissue, allowing pathologists for giving the definitive diagnosis, revealed by characteristic "sulfur granules". The authors report herein the case of a 47-year-old man who presented with diarrhoea and abdominal pain. Abdominal computed tomography evoked complicated inflammatory bowel disease and surgical procedure was decided. Laparoscopic exploration did not provide further significant information, and laparotomy with diseased bowel resection was performed. Pathology demonstrated "sulfur granules" and allowed the diagnosis of abdominal actinomycosis. This case demonstrated that abdominal actinomycosis should be included in the differential diagnosis when computed tomography shows an infiltrative and inflammatory mass.