A case of primary perianal actinomycosis

Actinomycosis is a chronic infection, which mainly affects of the cervicofacial area, thorax or abdomen, and is caused by anaerobic Actinomyces. The predilection site of abdominal involvement is the appendix and cecum. Although perianal actinomycosis as a secondary site of abdominal actinomycotic disease is a well known presentation, primary perianal actinomycosis without involvement of the internal organs is rare. We report a case of primary perianal actinomycosis. A 65-year-old male presented with a recurrent perianal abscess. Histopathologic findings showed acute and chronic inflammation with characteristic sulfur granules, composed of many basophilic, rod-like, Gram-positive bacilli, indicative of actinomycosis.