Actinomycosis of the masseter muscle: report of a case and review of the literature.

A rare case of cervicofacial actinomycosis arising primarily in the masseter muscle is described. The patient was a healthy 74-year-old woman who was not immunocompromised and had no other primary pathological finding in the oral cavity. The importance of the differential diagnosis for this unusual infection is demonstrated with tumoral pathological findings. Possible predisposing factors as well as diagnostic and therapeutic methods are discussed.