squamous metaplasia

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

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.

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).

Localization

 bronchial squamous metaplasia
 cervical squamous metaplasia
 squamous metaplasia of extrahepatic bile duct

Images

 Squamous metaplasia of extrahepatic bile duct

• https://twitter.com/hhaltasmd/status/747347924460396544
• https://twitter.com/hhaltasmd/status/747369047575126016

 Wikimedia: immature squamous metaplasia of the anus.

See also

 bile ducts

• extrahepatic bile duct

  epithelial anomalies

• squamous metaplasia
• squamous cell dysplasia