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 polyp in left middle meatus with normal surrounding mucosa. (Courtesy of William Clark, MD.)
Nasal polyps are benign lesions arising from the mucosa of the nasal passages including the paranasal sinuses. They are most commonly semitransparent.
- 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.
- 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.
Nasal polyp in right nasal cavity in a patient with inflamed mucosa from allergic rhinitis. (Courtesy of William Clark, MD.)
- The middle meatus is the most common location.
- 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).
CT scan showing polyps (asterisk) and bilateral opacified maxillary sinuses (MS). Note the nasal polyp appears to be coming from the left maxillary sinus and is above the inferior turbinate. (Courtesy of Richard P. Usatine, MD.)
- 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 ...