Squamous metaplasia is a benign non-cancerous change (metaplasia) of surfacing lining cells (epithelium) to a squamous morphology.

Micrograph showing squamous metaplasia (centre of image) in an atypical polypoid adenomyoma. H&E stain

Location

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Common sites for squamous metaplasia include the bladder and cervix. Smokers often exhibit squamous metaplasia in the linings of their airways. These changes don't signify a specific disease, but rather usually represent the body's response to stress or irritation. Vitamin A deficiency or overdose can also lead to squamous metaplasia.[1]

Uterine cervix

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In regard to the cervix, squamous metaplasia can sometimes be found in the endocervix, as it is composed of simple columnar epithelium, whereas the ectocervix is composed of stratified squamous non-keratinized epithelium.[2]

Significance

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Squamous metaplasia may be seen in the context of benign lesions (e.g., atypical polypoid adenomyoma), chronic irritation, or cancer (e.g., endometrioid endometrial carcinoma), as well as pleomorphic adenoma.

See also

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References

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  1. ^ Goralczyk, R (2009). "β-Carotene and Lung Cancer in Smokers: Review of Hypotheses and Status of Research". Nutrition and Cancer. 61 (6): 767–774. doi:10.1080/01635580903285155. PMID 20155614.
  2. ^ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; & Mitchell, Richard N. (2007) Robbins Basic Pathology (8th ed.). Saunders Elsevier. pp. 716-720 ISBN 978-1-4160-2973-1