35-year-old male suffers from frequent watery nasal discharge and an urge to sneeze. Surgical removal of nasal polyps.(Description see also slide 258)
- Focal replacement of the respiratory epithelium with a squamous, usually non-keratinizing epithelium.
- Foci with hyperplasia of the basal layer, a precursor to squamous metaplasia.
- Stromal edema and inflammatory infiltrate.
Pathogenesis: Chronic, mechanical damage to the mucosa.
Consequences: Respiratory epithelium may loose capacity to efficiently secrete mucous. Ciliary function may be impaired.