Physiological changes of the cervical epithelium – Congenital transformation zone (CTZ)
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The congenital transformation zone (CTZ) is a variant of intrauterine squamous metaplasia in which there is excessive maturation of the superficial layers of the squamous epithelium and incomplete maturation of the deeper layers. This is a deviation from the normal metaplastic process in utero and does not have any neoplastic potential. The condition is seen in 3–5% of young women. The condition is visible only while performing VIA or colposcopy. No treatment is required, and these changes disappear with age. After application of acetic acid to the cervix, the CTZ appears as a large oblong (lozenge-shaped) thin acetowhite area. The white patch often extends from the anterior fornix to the posterior fornix of the vagina.
The next section discusses the genesis of cervical cancer.