The Unilateral Nasal Mass in a Young Man
A 24-year-old man presents with 6 months of progressive left nasal obstruction, intermittent epistaxis and a dull left-sided facial ache. He has no history of trauma, no visual symptoms and no weight loss. On anterior rhinoscopy there is a smooth, pale, fleshy mass filling the left nasal cavity, pushing the septum to the right; the mass does not bleed on light touch. The left cheek is mildly full and the left eye is displaced laterally by about 3 mm on comparison. Nasal endoscopy shows the mass arising from the region of the middle meatus and extending posteriorly; the choana is partly visible. He is otherwise fit and well and has never smoked.
1. List the differential diagnosis in order of likelihood and state which features in the history and examination point towards a benign versus a malignant process.
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Differential (most to least likely in a young non-smoker):
- Antrochoanal polyp - arises from the maxillary sinus, passes through the accessory ostium into the middle meatus and posterior choana; smooth, pale, non-bleeding, unilateral. This fits best.
- Inverted papilloma - unilateral, fleshy, arises from the lateral wall/middle meatus; can cause bony remodelling and is locally aggressive; 10% association with squamous cell carcinoma.
- Juvenile nasopharyngeal angiofibroma - adolescent male, epistaxis, but typically bleeds readily and arises from the sphenopalatine foramen; the non-bleeding nature here argues against it.
- Nasal dermoid or glioma - usually paediatric, midline.
- Malignancy (adenocarcinoma, SCC, olfactory neuroblastoma, lymphoma) - less likely at 24 and in a non-smoker, but must be excluded.
Benign features: smooth non-bleeding surface, no weight loss, no cranial neuropathy, no cervical lymphadenopathy, young age, no smoking.
Concerning features: progressive unilateral obstruction, intermittent epistaxis, facial ache, cheek fullness and lateral globe displacement indicating bony expansion or erosion. These mandate imaging and histology; they cannot be dismissed as benign on appearance alone.
2. What imaging would you request first, and how would you interpret the finding of a mass filling the maxillary antrum with widening of the accessory ostium and extension into the choana?
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First-line imaging is CT of the paranasal sinuses with contrast, with MRI reserved for soft-tissue characterisation or if malignancy or skull-base involvement is suspected.
The described pattern - opacification of the maxillary antrum, widening of the accessory ostium, and a dumbbell-shaped mass extending through the middle meatus into the posterior choana - is the classic appearance of an antrochoanal polyp. The antral component is the "handle" and the choanal component the "head" of the dumbbell.
Important interpretation points:
- Bony expansion without erosion supports a benign slow-growing lesion; focal erosion, destruction of the medial maxillary wall, or extension into the orbit/pterygopalatine fossa raises suspicion of inverted papilloma or malignancy and warrants MRI.
- Widening of the ostium is a pressure effect, not invasion.
- The lateral globe displacement and cheek fullness reflect sinus expansion rather than orbital invasion, but orbital involvement must be excluded on imaging.
I would proceed to endoscopic biopsy at the same sitting as definitive surgery only if the imaging is unequivocally benign; otherwise biopsy first.
3. At endoscopic surgery the polyp is removed but the antral portion cannot be reached through the middle meatus. What is your surgical strategy, and how do you counsel him about recurrence?
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The antral portion must be addressed or the polyp will recur. Options, in order of preference:
- Middle meatal antrostomy with enlargement and removal of the antral component under endoscopic vision; if the ostium is too small, extend it posteriorly and inferiorly.
- Mini-trephine or canine fossa puncture to access the antrum and clear the polyp base.
- Endoscopic modified medial maxillectomy if the antral component is large or adherent.
- Combined endoscopic and Caldwell-Luc approach in refractory or recurrent cases.
The key principle is complete removal of the antral base and mucosa, not just the choanal portion.
Counselling: recurrence rates after adequate surgery are low (roughly 5-15%), but are higher if the antral component is left behind or if there is an underlying allergic or infective predisposition. I would explain that:
- The procedure is done through the nose with no external scar.
- He should expect nasal crusting and congestion for 2-4 weeks and will need saline irrigation and outpatient debridement.
- He must return if obstruction, bleeding or visual symptoms recur.
- Histology will confirm the diagnosis and exclude inverted papilloma, which would change follow-up to regular endoscopic surveillance.