Epithelial atypia and squamous metaplasia in nasal polyps.

Fifteen routine nasal polypectomy specimens submitted to our laboratory over an eight-month period were noted to show marked atypia within areas of squamous metaplasia to a degree suggestive of dysplasia. Reviewing the literature revealed little published work in this area, especially recently. Further nasal polyp cases from this, and a similar previous time period, were re-examined, and possible causes for these changes discussed.