An 8-year-old presents with unilateral nasal obstruction, hypernasal speech, and a smooth, fleshy, greyish midline polypoidal mass arising from the roof of the nasopharynx visualised on posterior rhinoscopy. CT shows a well-circumscribed mass extending from the sphenoid sinus. The characteristic feature that distinguishes this from a choanal polyp is:
- A It arises from the antrum of the maxillary sinus
- B It produces profuse epistaxis on probing
- C It arises from the roof/posterior wall of the nasopharynx, may contain CSF, and may connect to an intracranial component (encephalocele or meningoencephalocele) ✓
- D Histology shows dense fibrovascular stroma without epithelial lining
Correct answer: C. It arises from the roof/posterior wall of the nasopharynx, may contain CSF, and may connect to an intracranial component (encephalocele or meningoencephalocele)
Explanation
A smooth, compressible midline polypoidal mass in the nasopharynx of a child arising from the sphenoid/roof region should raise suspicion for a sphenoid encephalocele or nasal glioma/heterotopia before any biopsy or manipulation. Key distinguishing features from a choanal polyp: midline location, roof/posterior origin, connection to skull base on CT/MRI, potential CSF content, and risk of meningitis or CSF leak if biopsied blindly. Antrochoanal polyps arise from the maxillary antrum and extend through the choana. MRI with gadolinium is mandatory before biopsy.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.