Nasal cavity, paranasal sinuses, nasopharynx
General
Normal histology

Author: Nat Pernick, M.D. (see Authors page)

Revised: 16 May 2018, last major update November 2004

Copyright: (c) 2004-2018, PathologyOutlines.com, Inc.

PubMed Search: Normal histology nasal cavity[TI]

Table of Contents
Definition / general
Cite this page: Pernick, N. Normal histology. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/nasalnormalhistology.html. Accessed November 18th, 2018.
Definition / general
Nasal cavity
  • Lined by stratified squamous and respiratory type pseudostratified columnar epithelium, separated by transitional epithelium in some places
  • Respiratory mucosa (also called Schneiderian membrane) may contain goblet cells; may undergo squamous metaplasia
  • Superior third of nasal septum, superior turbinate and cribriform plate are covered with thinner olfactory mucosa, usually patchy in adults, which has neuroendocrine features
  • Seromucinous glands (resembling salivary glands) are present in submucosa, numerous near eustachian tube opening of nasopharynx, may undergo oncocytic metaplasia with increasing age
  • Normally no lymphoid tissue

Nasopharynx
  • Lined by stratified squamous epithelium (inferior anterior and posterior walls and anterior lateral walls) and respiratory type epithelium (around nasal choanae and roof of posterior wall); remaining areas have mixtures of squamous and respiratory or intermediate epithelium (also called transitional although it does not resemble urothelium ultrastructurally)
  • Intermediate epithelium is usually concentrated as a wavy ring at junction of nasopharynx and oropharynx
  • Seromucinous glands may undergo oncocytic metaplasia and rarely form a mass or obstruct eustachian tube
  • Abundant lymphoid tissue present, particularly at rim of eustachian tube opening (Gerlach tonsil); functionally equivalent to that of GI tract or mucosal associated lymphoid tissue (MALT)

Paranasal sinuses
  • Mucosa is continuous with nasal cavity and identical (respiratory type epithelium) but thinner and with fewer goblet cells and seromucinous glands
  • Normally no lymphoid tissue