Changes

{{Further|Tumor evaluationEvaluation of suspected malignancies}}[[File:Histopathology of a nasal polyp.jpg|thumb|'''Benign nasal polyp ''' (not otherwise specified), consisting of hyperplastic edematous connective tissue with some seromucous glands and cells representing inflammation (mostly neutrophils and eosinophils). In early stages, the surface of the nasal polyp is covered by normal respiratory epithelium, but later it undergoes metaplastic change to squamous type epithelium (because of the constant irritation and inflammation). The submucosa shows large intercellular spaces filled with serous fluid.<ref>{{Cite book|url=https://books.google.com/books?id=Zm3jBwAAQBAJ&pg=PA168|title=Ear, Nose and Throat Histopathology|last=Michaels|first=Leslie|date=2012-12-06|publisher=Springer Science & Business Media|isbn=9781447133322|language=en|page=168}}</ref>]]

File:Histopathology of inverted papilloma.jpg|'''Inverted papilloma''', wherein the surface epithelial cells grow downward into the underlying supportive tissue.File:Histopathology of nasal squamous papilloma.jpg|'''Squamous papilloma''', with acanthosis and hyperkerratosis.