Antrochoanal polyp derived from periapical granuloma

Antrochoanal polyp （ACP） is an infrequent, benign polypoid lesion that stems from the edematous mucosa of the maxillary sinus, grows from the natural or accessory ostium to the middle meatus, and protrudes toward the choana and nasopharynx. Although the exact causes of ACP are still unknown, chronic sinusitis, allergy, and lower respiratory tract infections are often related to ACE2 Our report is an ACP arising from a secondary infection of the periapical granuloma in the maxillary sinus. Its possible pathological mechanism, unique clinical features, and treatment are also discussed.