Pseudo-colonic carcinoma caused by abdominal actinomycosis: report of two cases.

Background: Abdominal actinomycosis is an infrequent chronic, suppurative infection caused by the aerobic gram-positive bands Actinomyces israelii.

Patient Presentation: We report two cases of abdominal actinomycosis, simulating colon cancer. Before operation, both patients presented with abdominal pain and a palpable mass. Abdominal computed tomography (CT) revealed an infiltrating irregular mass in the cecum and transverse colon, respectively. Surgical intervention was then performed under the impression of colonic malignancy.

Conclusion: Postoperatively, pathologic examination confirmed the diagnosis of abdominal actinomycosis in which the characteristic finding of sulfur granules in the resected specimen was demonstrated. After surgery, the patients continued antibiotic treatment with ampicillin for 2 months at our OPD and had no signs of recurrence 1 year after surgery.