transformation zone
Also written as: TZ — Transformation Zone
Area of the cervix where squamous and columnar epithelia meet, the primary site for cervical dysplasia.
Full Definition
The transformation zone (TZ) is the dynamic area of the cervix located between the original squamous epithelium and the columnar epithelium, where squamous metaplasia actively occurs. This region represents the junction between the ectocervix and endocervix and is the most common site for cervical intraepithelial neoplasia and invasive carcinoma development. Adequate visualization of the entire transformation zone is essential during colposcopy and cervical cancer screening, as lesions hidden within this area may be missed during examination.
Usage
Usage note: Always document whether the entire transformation zone is visible during colposcopy.
In Context
- "Colposcopy revealed acetowhite changes within the transformation zone requiring biopsy." — Colposcopy report
- "The entire transformation zone was visualized and appeared normal during examination." — Screening examination