General Medical Information

Nasal Polyposis

Richard L. Mabry

Nasal polyps are pale yellow to clear single- or multiple-peduncled benign nasal masses arising from mucoperiosteal or mucoperichondrial tissue and filled with edematous stroma and inflammatory cells. These masses can grow through an accumulation of intracellular fluid, contributed by a random vascular bed, deposition of polysaccharides, elevated sodium absorption, and increased chloride ion permeability relative to normal submucosa. Successive episodes of localized inflammatory edema can facilitate transformation from normal to polypoid abnormal submucosa. Recurrent nasal polyposis has been associated with aspirin triad disease or the Samter triad (concurrent aspirin sensitivity, asthma, and nasal polyposis), cystic fibrosis (strongly suggested among children with polyps), and fungal sinus infection. Immunoglobulin E–mediated allergic mechanisms have not been definitively found to be an important factor in nasal polyposis. Among children, nasal polyposis usually is associated with cystic fibrosis or asthma. These patients should undergo screening for those associated diseases.

Nasal polyposis is characterized by chronic eosinophilic inflammation. These eosinophils and other inflammatory cells, such as mast cells and neutrophils, produce cytokines and other inflammatory mediators. The mediators can increase polyp water retention by increasing sodium ion uptake. Among patients with aspirin triad disease, aspirin is believed to block cyclooxygenase metabolism of arachidonic acid while stimulating 5-lipooxygenase, which leads to overproduction of leukotrienes. Leukotrienes increase vascular permeability, increase mucous secretion, and cause bronchoconstriction.

Patients with nasal or sinonasal polyposis typically have progressive nasal stuffiness, rhinorrhea, and facial pain or headaches not necessarily associated with the extent of disease or with a particular nasal region located just internal to a focus of pain. Anosmia occurs less frequently and is directly related to the extent of polyposis. The most important adverse effect of nasal polyposis is swelling of the infundibulum, followed by obstructive sinonasal disease and recurrent or chronic sinusitis. An inverted papilloma or other neoplasm, such as olfactory esthesioneuroblastoma, although they are exceedingly rare, can resemble benign polyp tissue. On paranasal sinus CT scans, isolated “polypoid” masses predominate when disease involves the nasal cavity. Air-fluid levels of the same approximate density can preclude delineation of these edematous masses in the sinuses. Computed tomography can be used to characterize the extent of disease so that appropriate therapy can be devised.

Medical management of nasal polyps with corticosteroids has met with some success. Intranasal glucocorticoids interfere with several steps in the inflammatory process. They decrease capillary permeability, decrease excretion in response to cholinergic stimulation in the nasal mucosa, and suppress cytokine synthesis in eosinophils, basophils, and lymphocytes. Glucocorticoids inhibit the influx of eosinophils and basophils into the nasal epithelium and decrease production of inflammatory mediators from arachidonic acid production. Nasal glucocorticoids have proved efficacious in reducing polyp size and reducing the recurrence of polyps after sinus surgery. Systemic glucocorticoids, administered in a short high burst with a rapid taper, have been used to manage this recurrent condition. Surgical intervention is indicated when polyposis is unresponsive to repeated courses of glucocorticoids and when antibiotic-resistant sinusitis is present. Oral antileukotriene medications have promise for the management of nasal polyposis due to aspirin triad disease.

Surgical excision of nasal polyps occurs solely or in concert with functional endoscopic sinus surgery and turbinectomy. Longer periods of remission are likely with endoscopic sinus surgery than with polypectomy alone, except in the care of patients with cystic fibrosis, among whom recurrence is equally likely regardless of approach. The surgical approach usually is intranasal. The Caldwell-Luc (alveolar fossa) approach rarely is indicated. Preoperative thin-section CT is recommended for determining the extent and characteristics of the disease and the associated surgical procedure and for identifying the variations in this complex anatomic field. The otolaryngologist must be prudent in preoperative counseling of patients with polyposis, because this condition is characterized by the need for several operations and by recurrence. If polypectomy can delay recurrence for 5 years or more, the surgical procedure is deemed successful.