|Classification and external resources|
Micrograph of a sinonasal polyp. H&E stain
Nasal polyps are polypoidal masses arising mainly from the mucous membranes of the nose and paranasal sinuses. They are overgrowths of the mucosa that frequently accompany allergic rhinitis. They are freely movable and nontender.
Nasal polyps are usually classified into antrochoanal polyps and ethmoidal polyps. Antrochoanal polyps arise from the maxillary sinuses and are the much less common, ethmoidal polyps arise from the ethmoidal sinuses. Antrochoanal polyps are usually single and unilateral whereas ethmoidal polyps are multiple and bilateral.
Symptoms of polyps include nasal congestion, sinusitis, anosmia (loss of smell), and secondary infection leading to headache. They may be removed by surgery, but are found to recur in about 70% of cases. Sinus surgery requires great amount of precision as this involves risk of damage to orbit matter.
The tendency to manifest multiple polyps is referred to as “polyposis”.
There are 2 major types of nasal polyps.
- Single, Unilateral
- Can originate from maxillary sinus
- Usually found in children
- Usually found in adults
The pathogenesis of nasal polyps is unknown. Nasal polyps are most commonly thought to be caused by allergy and rarely by cystic fibrosis although a significant number are associated with non-allergic adult asthma or no respiratory or allergic trigger that can be demonstrated. Nasal mucosa, particularly in the region of middle meatus becomes oedematous due to collection of extracellular fluid causing polypoidal change. Polyps which are sessile in the beginning become pedunculated due to gravity and excessive sneezing.
In early stages, surface of nasal polypi is covered by ciliated columnar epithelium, but later it undergoes metaplastic change to squamous type on atmospheric irritation. Submucosa shows large intercellular spaces filled with serous fluid.
These polyps have no relationship with colonic or uterine polyps. Irregular unilateral polyps particularly associated with pain or bleeding will require urgent investigation as they may represent an intranasal tumour.
There are various diseases associated with polyp formation:
- Chronic rhinosinusitis
- Aspirin intolerance/salicylate sensitivity
- Cystic fibrosis
- Kartagener's syndrome
- Young's syndrome
- Churg-Strauss syndrome
- Nasal mastocytosis
Exposure to some forms of chromium can cause nasal polyps and associated diseases.
Nasal polyps are most often treated with steroids or topical, but can also be treated with surgical methods.
Pre-post surgery, sinus rinses with a warm water (240 ml / 8 oz) mixed with a small amount (teaspoon) of salts (sodium chloride & sodium bicarbonate) can be very helpful to clear the sinuses. This method can be also used as a preventative measure to discourage the polyps from growing back and should be used in combination with a nasal steroid.
The removal of nasal polyps via surgery lasts approximately 45 minutes to 1 hour. The surgery can be done under general or local anaesthesia, and the polyps are removed using endoscopic surgery. Recovery from this type of surgery is anywhere from 1 to 3 weeks.
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