[Abdominal actinomycosis].

Actinomycosis is a non opportunistic chronic infection caused by a superior bacteria that forms grains in the pus or affected organs. Fifty four cases have been reported in the last 50 years in the chilean literature, 51% were abdominal actinomycoses, 25.5% pelvic and 18.5% pulmonary. Fourteen cases have been treated in the last 9 years at San Borja Arriaran. Of these 7 were abdominal (1 parietal and 6 visceral forms) and four involved the rectosigmoid; two were ileocecal and occurred after an appendicectomy. The presenting picture was of a giant abdominal mass in two cases (one with a colocutaneous fistula), rectal stricture in one case, tubo-ovarian abscess with colonic involvement in one case, parietal mass in one case and a fistula after an appendicectomy in two cases. Actinomyces Israelli was found in the histopathological study in three cases and in the bacteriological study in two. All visceral forms were treated with penicillin plus tetracycline or amoxicillin during 6 to 12 months with complete and permanent recovery. Two patients required a colonic resection due to a iatrogenic damage and an associated diverticular disease. Three patients required a colostomy to overcome the obstruction, all of them are asymptomatic and without colostomy 18 months to 8 years later. Due to its different presentation forms, actinomycosis has been called "the great pretender" and in several occasions the histological or bacteriological diagnosis is not achieved.