Nasal Polyps
ENT · Nose & PNS · lean revision notes
Nasal Polyps
Nasal polyps are non-neoplastic, oedematous, prolapsed masses of inflamed sinonasal mucosa that protrude into the nasal cavity. They are a favourite NEET PG topic because two clinically opposite entities — ethmoidal (multiple, bilateral, allergic) and antrochoanal (single, unilateral, of Killian) — must be sharply distinguished, and because of the classic Samter's triad, CT staging, and the notoriously high recurrence after surgery.
High-yield: A polyp is insensitive to probing and does not bleed on touch — this single bedside fact separates a benign polyp from a malignant mass or an angiofibroma, both of which bleed.
Definition & basic concept
A nasal polyp is the end-stage of chronically inflamed, oedematous mucosa that herniates under the influence of gravity and bilateral mucosal apposition. The mucosa imbibes fluid, the lamina propria becomes oedematous, and the dependent mucosa prolapses, pulling a "stalk" along with it. Polyps are not tumours — they are inflammatory/oedematous lesions, although they can mimic neoplasia clinically and radiologically.
Microscopically a polyp shows a loose, oedematous stroma, bilayered respiratory (pseudostratified ciliated columnar) epithelium, hyperplastic mucous glands, and an inflammatory infiltrate. In ethmoidal polyps the infiltrate is eosinophil-rich; in antrochoanal polyps it is comparatively neutrophilic / less eosinophilic.
Classification
The most examined classification is etiological/anatomical — ethmoidal vs antrochoanal.
| Feature | Ethmoidal polyps | Antrochoanal polyp (of Killian) |
|---|---|---|
| Number | Multiple | Single (solitary) |
| Laterality | Bilateral | Unilateral |
| Age group | Adults | Children & young adults |
| Site of origin | Ethmoidal sinuses / middle meatus | Maxillary antrum (near accessory ostium) |
| Associations | Allergy, asthma, aspirin triad, CF | Usually none (mild infection) |
| Eosinophils | Numerous (eosinophilic) | Few (neutrophilic) |
| Direction of growth | Anteriorly, toward nostril | Posteriorly, toward choana/nasopharynx |
| Recurrence | High | Low (if removed completely) |
| Treatment | Medical + FESS polypectomy | Caldwell-Luc / endoscopic removal of antral attachment |
High-yield: The antrochoanal polyp has three parts — an antral part (cyst in the maxillary sinus), a nasal part (in the nasal cavity), and a choanal part (in the nasopharynx). It has a trilobed (dumbbell) shape and grows backward, so it may present as a mass behind the soft palate.
Other types worth knowing:
- Sphenochoanal polyp — arises from the sphenoid sinus, also grows toward the choana (rarer).
- Aspirin-exacerbated respiratory disease (AERD)–associated polyps — part of Samter's triad.
- Polyps in cystic fibrosis and primary ciliary dyskinesia (Kartagener's) — suspect in any child with bilateral polyps.
Etiology & pathophysiology
The exact cause is multifactorial. The classic theory is the Bernoulli phenomenon / polyp-cycle: turbulent airflow through narrow clefts creates negative pressure, drawing oedema fluid into the dependent mucosa.
Underlying/associated conditions (must memorise):
- Allergic rhinitis and non-allergic eosinophilic rhinitis.
- Bronchial asthma (intrinsic asthma especially).
- Aspirin sensitivity → Samter's triad.
- Cystic fibrosis — commonest cause of nasal polyps in children; always test a child with polyps for CF (sweat chloride).
- Primary ciliary dyskinesia / Kartagener's syndrome.
- Allergic fungal rhinosinusitis — type I + type III hypersensitivity to fungi (e.g. Aspergillus, dematiaceous fungi), produces thick eosinophilic "allergic mucin".
- Churg-Strauss syndrome (eosinophilic granulomatosis with polyangiitis).
- Young's syndrome (sinopulmonary disease + azoospermia).
High-yield (Samter's / Widal's triad / AERD): Aspirin (NSAID) sensitivity + Bronchial asthma + Nasal polyps. Mechanism = COX-1 inhibition shunts arachidonic acid down the lipoxygenase pathway → excess cysteinyl leukotrienes → intense eosinophilic inflammation. These patients have the most aggressive, recurrence-prone polyps.
Mnemonic for Samter's triad — "ASA": Asthma, Samter's = Aspirin sensitivity, Anti = nasal polyps (think "Aspirin Sensitivity Asthma").
Clinical features
Common to all polyps:
- Bilateral nasal obstruction (ethmoidal) or unilateral obstruction (antrochoanal) — progressive, persistent.
- Anosmia / hyposmia (loss of smell) — prominent in ethmoidal polyposis.
- Nasal discharge (watery → mucopurulent if infected), postnasal drip.
- Hyponasal speech (rhinolalia clausa), mouth breathing, snoring.
- Headache and dull frontal heaviness.
- Frog-face deformity / broadening of nasal bridge & hypertelorism — with massive long-standing polyposis (especially in children, due to splaying of nasal bones). This is a classic image.
On anterior rhinoscopy / endoscopy:
- Ethmoidal: multiple, smooth, glistening, pale, grape-like, semitransparent masses in the middle meatus.
- Antrochoanal: single smooth pale mass, often seen better posteriorly; may be visible on posterior rhinoscopy in the choana/nasopharynx.
High-yield: Polyps are mobile, pale, non-tender, insensitive to probing, and do NOT bleed. A pink/red, firm, bleeding mass that is sensitive in an adolescent boy = juvenile nasopharyngeal angiofibroma, NOT a polyp. A unilateral bleeding "polypoidal" mass in an elderly person → rule out malignancy (biopsy).
Diagnosis & investigation of choice
Stepwise approach:
Clinical suspicion → Anterior rhinoscopy → Diagnostic nasal endoscopy → Non-contrast CT PNS (investigation of choice for staging) → Histopathology if any atypical feature → Work-up for cause (allergy, sweat chloride, aspirin history).
- Diagnostic nasal endoscopy (DNE): confirms the polyp, its origin (middle meatus vs antral), number, and laterality. First-line clinical tool.
- CT scan of paranasal sinuses (coronal, non-contrast) is the imaging investigation of choice. It:
- delineates extent and sinus opacification,
- maps the osteomeatal complex,
- identifies anatomical variations before FESS,
- is essential for staging and surgical planning.
- For antrochoanal polyp, CT shows a soft-tissue mass filling the maxillary sinus extending through a widened ostium into the choana.
- MRI — reserved for suspected intracranial/intraorbital extension, suspected malignancy, or fungal disease (helps differentiate inspissated secretions from tumour).
- Histopathology / biopsy — mandatory for any unilateral, bleeding, or atypical mass to exclude malignancy, inverted papilloma, or fungal disease. Do not biopsy a suspected angiofibroma in the OPD (haemorrhage risk).
- Cause work-up: allergy testing/serum IgE, sweat chloride test in children (CF), aspirin sensitivity history, fungal smear/culture and eosinophilic mucin examination if AFRS suspected.
Useful staging scores
| System | Use |
|---|---|
| Lund-Mackay score | CT-based staging of chronic rhinosinusitis/polyposis; scores each sinus 0–2 and OMC 0/2; total 0–24 per side. Guides surgery and research. |
| Lund-Kennedy score | Endoscopic scoring (polyps, oedema, discharge, scarring, crusting) — used post-operatively to monitor. |
| Meltzer / clinical polyp grade | Grade 0 (none) → Grade 1 (confined to middle meatus) → Grade 2 (below middle turbinate) → Grade 3 (massive, reaching floor). |
High-yield: CT PNS (coronal, plain) is the single best investigation for nasal polyposis and is mandatory before FESS — it is the "road map" that warns of a dehiscent lamina papyracea, low cribriform plate (Keros classification), or Onodi cell.
Management & drug of choice
Management is medical first for ethmoidal polyposis, surgical for antrochoanal polyp (and for medically refractory ethmoidal disease).
Medical (ethmoidal/eosinophilic polyps)
- Intranasal corticosteroids (e.g. mometasone, fluticasone, budesonide) — first-line and the mainstay/drug of choice for ethmoidal polyps; shrink polyps, relieve obstruction, reduce recurrence.
- Short course of oral corticosteroids (prednisolone) — for severe, obstructing polyposis ("medical polypectomy") and to shrink polyps before surgery.
- Saline nasal irrigation, treatment of allergy (antihistamines), leukotriene receptor antagonists (montelukast) — especially useful in AERD/Samter's triad.
- Antibiotics (e.g. macrolides) if secondary infection.
- Biologics for severe refractory eosinophilic polyposis with type-2 inflammation: dupilumab (anti-IL-4Rα — most established), omalizumab (anti-IgE), mepolizumab (anti-IL-5). Increasingly tested.
- Aspirin desensitisation in confirmed AERD reduces recurrence.
Surgical
- Functional Endoscopic Sinus Surgery (FESS) with polypectomy — standard surgical treatment for ethmoidal polyposis; removes polyps and opens the sinuses while preserving mucosa.
- Antrochoanal polyp: must remove the antral origin completely or it recurs. Options: endoscopic removal via wide middle meatal antrostomy (preferred today) or classic Caldwell-Luc operation (sublabial approach into the maxillary antrum) when the antral attachment is inaccessible endoscopically.
- Simple avulsion with a snare alone (old "polypectomy") gives high recurrence because the origin is left behind.
Treatment flow (ethmoidal): Confirm by DNE → CT PNS staging → Intranasal steroids ± short oral steroid → If refractory/massive → FESS + polypectomy → Continue topical steroids + treat underlying cause + biologics if type-2 → Surveillance for recurrence.
High-yield: Intranasal steroids = drug of choice for ethmoidal polyps. Complete removal of the antral attachment (endoscopic antrostomy or Caldwell-Luc) = treatment of antrochoanal polyp. Recurrence is high in ethmoidal, low in antrochoanal if origin excised.
Complications
Of the disease:
- Persistent nasal obstruction, anosmia, OSA/snoring.
- Recurrent/chronic rhinosinusitis, mucocele formation.
- Cosmetic deformity — broadening of nose, frog-face, hypertelorism, proptosis (massive polyposis can erode bone).
- Orbital and rarely intracranial extension with aggressive polyposis/AFRS.
Of surgery (FESS):
- Orbital injury — periorbital ecchymosis, orbital haematoma, diplopia (medial rectus injury), blindness (optic nerve/ophthalmic artery injury). Lamina papyracea is the thin medial orbital wall at risk.
- CSF rhinorrhoea — injury to the cribriform plate / fovea ethmoidalis (anterior ethmoidal artery region); risk higher with low Keros type 3 cribriform plate.
- Haemorrhage (anterior/posterior ethmoidal or sphenopalatine artery), synechiae, recurrence, loss of smell.
High-yield: The two most feared FESS complications are orbital injury (blindness/diplopia) and CSF leak. Knowledge of the lamina papyracea (orbit) and fovea ethmoidalis/cribriform plate (skull base) is essential.
Key differentials
| Lesion | Distinguishing feature |
|---|---|
| Hypertrophied turbinate | Pink, sensitive to probe, bleeds, shrinks with decongestant; attached to lateral wall. Polyp = pale, insensitive, no bleed, no shrink. |
| Juvenile nasopharyngeal angiofibroma | Adolescent male, profuse epistaxis, red firm mass, bowing of posterior maxillary wall (Holman-Miller sign); NEVER biopsy in OPD. |
| Inverted (Schneiderian) papilloma | Unilateral, may turn malignant (SCC), needs wide excision; HPV-associated. |
| Sinonasal malignancy | Elderly, unilateral bleeding mass, pain, bony erosion, cranial nerve signs — biopsy mandatory. |
| Meningoencephalocele | Soft pulsatile mass, expands on crying/straining, positive Furstenberg sign; never biopsy (CSF leak/meningitis). |
| Rhinosporidiosis | Strawberry-red, friable, bleeds easily, Rhinosporidium seeberi, history of pond bathing. |
High-yield: A single unilateral "polyp" in an adult/elderly is malignancy until proven otherwise → biopsy. A single unilateral mass with epistaxis in a teenage boy → angiofibroma → do NOT biopsy, do contrast CT/MRI/angiography.
Recently asked / exam angle
- One-liners that recur: Commonest cause of nasal polyp in children = cystic fibrosis. Antrochoanal polyp arises from the maxillary sinus and is also called the polyp of Killian. Polyp that grows backward into the nasopharynx = antrochoanal.
- Samter's triad / Widal's triad components and the leukotriene mechanism (aspirin → COX inhibition → lipoxygenase shunt). Frequently asked as "which drug worsens nasal polyps?" → aspirin/NSAIDs.
- Investigation of choice = CT PNS (coronal plain). Lund-Mackay used for staging.
- Drug of choice for ethmoidal polyps = intranasal corticosteroids.
- Caldwell-Luc operation is associated with antrochoanal polyp (and chronic maxillary sinusitis) — classic match-the-following.
- Image-based: grape-like glistening masses in the middle meatus (ethmoidal); trilobed/dumbbell mass extending into nasopharynx (antrochoanal); frog-face child.
- Furstenberg sign (encephalocele expands on jugular compression) vs Holman-Miller / antral sign (angiofibroma) — distinguishing "don't-touch" masses from polyps.
- Biologic of choice in severe eosinophilic polyposis = dupilumab (newer, increasingly tested).
- Allergic fungal rhinosinusitis — eosinophilic mucin, type I + III hypersensitivity, double-density / hyperdense material on CT.
Rapid revision
- Polyp = pale, smooth, mobile, insensitive, does NOT bleed — bleeding mass means rethink (angiofibroma/malignancy).
- Ethmoidal = multiple + bilateral + adults + eosinophilic + high recurrence.
- Antrochoanal (Killian) = single + unilateral + children + maxillary sinus origin + grows toward choana + trilobed/dumbbell.
- Commonest cause of polyp in a child = cystic fibrosis → do sweat chloride test.
- Samter's/Widal's triad = aspirin sensitivity + asthma + nasal polyps; mechanism via cysteinyl leukotrienes.
- Investigation of choice = plain coronal CT PNS; Lund-Mackay for staging, Lund-Kennedy for endoscopy.
- Drug of choice (ethmoidal) = intranasal corticosteroids; oral steroids for medical polypectomy; montelukast in AERD.
- Antrochoanal treatment = complete removal of antral attachment — endoscopic antrostomy or Caldwell-Luc; snare avulsion alone → recurrence.
- FESS is the surgery for ethmoidal polyposis; feared complications = orbital injury (blindness/diplopia) and CSF rhinorrhoea.
- Massive polyposis → frog-face deformity, hypertelorism, broad nose.
- Dupilumab (anti-IL-4Rα) is the leading biologic for severe type-2 eosinophilic polyposis.
- Never biopsy a suspected angiofibroma (teen boy + epistaxis) or encephalocele (positive Furstenberg sign) in the OPD.