RESUMO
RATIONALE: Osteoma with actinomycosis is a very rare disease in the nasal cavity. PATIENT CONCERNS: We report a case of a 17-year-old female student who presented with nasal obstruction and rhinorrhea for 6 months. DIAGNOSES: The preoperative finding was osteoma covered with yellowish polypoid material. INTERVENTIONS: We performed endoscopic sinus surgery, which included excision of the tumor and medication with oral penicillin for 8 weeks. OUTCOMES: Postoperative recovery was uneventful. There was no evidence of tumor recurrence during the 1-year period after surgery. CONCLUSION: Anaerobic conditions as a result of allergic rhinitis and narrowed nasal cavity because of osteoma can be the cause of formation of actinomycosis. Clinicians should note that osteoma with actinomycosis can be treated with surgical removal of the tumor and short-term antibiotic therapy.