Actinomycosis imitating nasopharyngeal carcinoma.

The incidence of nasopharyngeal actinomycosis is exceedingly rare. To our knowledge, only 1 case has been reported previously. This article presents 4 cases of actinomycosis involving the nasopharynx that imitated nasopharyngeal carcinoma. Acidic gas exposure and farming of aquatic products are possibly involved in the pathogenesis of nasopharyngeal actinomycosis. Patients in the case studies completely recovered after 4 weeks of oral antibiotic treatment. We recommend including actinomycosis in the differential diagnosis of nasopharyngeal neoplasms.