A 12-year-old boy presents with progressive left-sided nasal obstruction. Endoscopy shows a single smooth pale grey mass filling the left nasal cavity and extending into the nasopharynx. CT paranasal sinuses shows a mass arising from the mucosa of the left maxillary antrum and passing through its accessory ostium. The most likely diagnosis is:

• A Ethmoidal polyposis
• B Juvenile nasopharyngeal angiofibroma
• C Inverted papilloma
• D Antrochoanal polyp ✓

Explanation

An antrochoanal polyp (Killian polyp) is a single, unilateral polyp that arises from maxillary antral mucosa, exits through the accessory or widened natural ostium, and extends backward into the choana and nasopharynx. It is typically seen in children and young adults. Juvenile nasopharyngeal angiofibroma is vascular, bleeds profusely on biopsy, and arises near the sphenopalatine foramen; ethmoidal polyposis produces multiple bilateral polyps, not one solitary mass.

Reference: Scott-Brown's Otorhinolaryngology and Head and Neck Surgery, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.