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Nasal Polyps

Nasal polyps are pedunculated swellings within the nasal cavity. They are almost always benign and a result of inflammatory swelling within the nose or paranasal sinuses. The nature of the inflammation varies: chronic infective, allergic and other non-allergic rhinitis are the usual causes. Nasal polyps are usually a manifestation of chronic rhinosinusitis.

Ten percent of nasal polyps are not inflammatory in nature and are considered neoplastic (but very rarely malignant). Inverting papilloma, malignant melanoma, adenocarcinoma, squamous cell carcinoma, olfactory neuroblastoma are all possibilities but are not discussed here.



Macroscopically polyps are smooth, yellow-gray and shiny. They resemble grapes but individual polyps can become very large. (click here to see an example). Polyps are usually multiple, especially if they come from the ethmoid sinuses, and they are generally bilateral. See the section on unilateral polyps below for further information on these.


Microscopically polyps are covered in respiratory epithelium and beneath this a markedly oedematous connective tissue stroma. Within the stroma will be found eosinophils (even when it is not a polyp of allergic origin) and histiocytes.

The image shows polyps (P) arising from the middle meatus on the patient's right side. The middle meatus is the space medial to the middle turbinate (MT). Note that the septum and inferior turbinate (IT) are partly obscured by the polyps. To the right is a schematic of the clinical image.

Clinical Features


When thinking about the symptoms remember that polyps are caused by inflammation of the nasal and sinus lining and, therefore, there will be the symptoms of rhinitis as well as of the polyps.


Small polyps confined to the middle meatus (the cleft found lateral to the middle turbinate) probably will not cause nasal obstruction while large polyps that fill the nasal cavity will. However, even small polyps can predispose to recurring sinusitis by blocking off sinus ostia and causing a buildup of mucus secretion within the sinus.


Other symptoms include a loss of the senses of smell and taste, 'pressure' sensation in the forehead and headache.


In extreme cases, the polyps may appear at the nostril and even widen the nose and intercanthal distance. This is uncommon.

In this diagram the polyps are coloured green. Polyps start as a small swelling within the lining of an ethmoid sinus (remember there may be between 5 and 15 on each side). As the swelling increases the mucosa starts to bulge out of the sinus and into the middle meatus. Ultimately the polyp appears in the nasal fossa. 


Very little is required. Tests for underlying allergy are useful in the long term management of the underlying cause.

CT scanning of the paranasal sinuses is only useful as a planning tool for surgery and plain radiology of the sinuses is unhelpful in all but rare cases. For an example of a CT sinus please click here.



There are two main options: Medical treatment or Surgical removal.


Medical treatment is usually tried first. Topical nasal steroids are the mainstay of early management and they are helpful when the polyps are small or moderate in size. If they become massive then oral steroid for a short period will help. Antihistamines are only of help if there is an underlying allergy (and this is uncommon). For more information on nasal sprays please consult or pharmacology section on the topic


Surgical treatment is performed when:


1. Medical management has failed


2. The polyps are too large for topical steroids


3. When the polyp is unilateral (because of the small risk of malignancy).


The operation may be a simple polypectomy or may be combined with septal and sinus surgery e.g. ethmoidectomy.


FESS is the modern approach to sinus and polyp surgery. It utilises rigid endoscopes to give an exceptional view of the nose and sinus cavities and is often combined with the use of television monitoring and powered nasal instruments for removal of disease.


Please review the Procedures section for more information on FESSHowever, it simply aims to return sinus functional to normal with the absolute minimum of surgery.


Polyps are prone to recur. This may happen within months or many years later. They recur because the conditions that created them (e.g. chronic rhinosinusitis) are chronic conditions. Long-term treatment of rhinitis by topical steroids and/or antihistamines is needed for many patients. If the polyps return very frequently then an ethmoidectomy may be advisable.

Antrochoanal Polyp

This is an uncommon, benign, solitary polyp that arises in the maxillary sinus (unlike typical nasal polyps that arise in the ethmoids). As it gets bigger it starts to protrude out of the maxilla and into the nose. Further growth occurs and the polyp enlarges backwards towards the choana and may eventually become so large that it is visible through the mouth. As it begins in the maxillary antrum and enlarges towards the choana it is called an antrochoanal polyp.

The treatment is by surgical removal but these polyps are sometimes so large that they have to be 'delivered' through the mouth after removal from the antrum.

Unilateral Polyps

Nasal polyps are nearly always bilateral and inflammatory in origin. However, occasionally one will find a unilateral polyp. These are important because they may represent a pre-neoplastic or neoplastic cause.

Overall, they make up less than 1% of all malignancies and men are more than twice as likely to suffer them. They generally occur after the age of 50.

Tumours may be benign or malignant and 75% of them arise in the maxillary sinus.

Benign tumours include: Osteomas (the commonest benign tumour), and Inverting Papilloma being the second commonest (although this has a malignant potential).

Malignancies include: squamous cell carcinoma, adenocarcinoma, malignant melanoma and olfactory neuroblastoma.

A patient comes to you with a unilateral polyp...

The commonest cause of this is a simple inflammatory polyp that happens to be only on one side. However, the concern is that it represents a neoplastic polyp.

History and examination is directed to exploring the red flag symptoms and signs of a possible malignancy. Symptoms and signs that cause concern in a patient with a unilateral polyp are:


1. Epstaxis

2. Infra-orbital anaesthesia

3. Toothache

4. Facial swelling or pain

5. Trismus

6. Double vision


1. Numbness or swelling in the cheek

2. Proptosis or ophthalmoplegia

3. Evidence of tumour in the mouth or hard palate

4. Loose teeth or newly poor-fitting dentures

5. Oroantral fistula that won't heal

6. Numbness of the hard palate

7. Glossopharyngeal or vagal palsy

8. CSF leak

9. Regional lymph nodes

If you see a unilateral polyp, refer to the local ENT Department. Provide a good history concentrating on red flag symptoms and signs. Do not assume that it is benign even though it most probably is.

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