Clinical features of abdominal actinomycosis: a 15-year experience of a single institute.

This study was designed to evaluate the clinical features of abdominal actinomycosis and to assess its therapeutic outcome. We reviewed patients with abdominal actinomycosis in Seoul St. Mary hospital, between January 1994 and January 2010. Twenty-three patients (5 male and 18 female, mean age, 47.8 yr; range, 6-75 yr), with abdominal actinomycosis were included. Emergency surgery was performed in 50% due to symptoms of peritonitis. The common presentation on preoperative computerized tomography was a mass with abscess, mimicking malignancy. The mean tumor size was 7.0 cm (range, 2.5-10.5). In all patients, actinomycotic masses were surgically removed. Mean duration of hospital stay was 17.8 days (range, 5-49). Long term oral antibiotic treatment (mean 4.2 months; range, 0.5-7.0 months) were administered to all patients. All patients were free of recurrence after a median follow up of 30.0 months (mean 35.5 ± 14.8 months, range, 10.0-70.0 months); recurrence was not seen in any patient. In conclusion, abdominal actinomycosis should be included as a differential diagnosis when an unusual abdominal mass or abscess presents on abdominal CT. Assertive removal of necrotic tissue with surgical drainage and long term antibiotic treatment provide a good prognosis in patients with actinomycosis.