A rare case of ascending colon actinomycosis mimicking cancer

BACKGROUND Actinomycosis is a rare inflammatory disease caused by an anaerobic bacterium that can rarely affect the large intestine. CASE PRESENTATION We present a rare case of a cecum and ascending colon actinomycosis in a 72 years old woman, mimicking clinically a malignant inflammatory tumor of the right colon. The patient complained of right lower quadrant pain. Although our first thought was a peri-appendiceal abscess, CT scan suggested a right colon tumor. The patient underwent a right colectomy and the histological examination of the specimen revealed colon actinomycosis. CONCLUSIONS Preoperative diagnosis in colon actinomycosis is difficult to achieve. Treatment of choice is antibiotics administration. A review of the possible pathogenesis and therapeutic modalities is also presented.