Squamous metaplasia

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

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

Location

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 can lead to squamous metaplasia.^{[citation needed]}

Uterine cervix

In regards 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 .

Significance

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).

See also

• Metaplasia
• Dysplasia
• Barrett esophagus - a columnar cell metaplasia of squamous epithelium