Chapter 30. Nasal Polyps

A 35-year-old man complains of unilateral nasal obstruction for the past several months of gradual onset. On examination of the nose, a nasal polyp is found (Figure 30-1).

Nasal polyps are benign lesions arising from the mucosa of the nasal passages including the paranasal sinuses. They are most commonly semitransparent.

See reference 1.

• Prevalence of 1% to 4% of adults; 0.1% of children of all races and classes.
• The male-to-female ratio in adults is approximately 2:1.
• Peak age of onset is 20 to 40 years old; rare in children younger than 10 years old.
• Associated with the following conditions:
  • Nonallergic and allergic rhinitis and rhinosinusitis.
  • Asthma—In 20% to 50% of patients with polyps.
  • Cystic fibrosis.
  • Aspirin intolerance—In 8% to 26% of patients with polyps.
  • Alcohol intolerance—In 50% of patients with polyps.

• The precise cause of nasal polyp formation is unknown.
• Infectious agents causing desquamation of the mucous membrane may play a triggering role.
• Activated epithelial cells appear to be the major source of mediators that induce an influx of inflammatory cells, including eosinophils prominently; these in turn lead to proliferation and activation of fibroblasts.2 Cytokines and growth factors play a role in maintaining the mucosal inflammation associated with polyps.
• Food allergies are strongly associated with nasal polyps.

Clinical Features

• The appearance is usually smooth and rounded (Figure 30-1).
• Moist and translucent (Figure 30-2).
• Variable size.
• Color ranging from nearly none to deep erythema.

Typical Distribution

• The middle meatus is the most common location.

Laboratory and Imaging

• Consider allergy testing.
• In children with multiple polyps, order sweat test to rule out cystic fibrosis.
• CT of the nose and paranasal sinuses may be indicated to evaluate extent of lesion(s) (Figure 30-3).

Biopsy

• Not usually indicated. Histology typically shows pseudostratified ciliary epithelium, edematous stroma, epithelial basement membrane, and proinflammatory cells with eosinophils present in 80% to 90% of cases.

Many relatively rare conditions can cause ...