General assesment includes the description of the:
• Adequacy of colposcopic examination
• Visibility of squamo-columnar junction
• Type of the transformation zone
Adequacy of colposcopic examination
Colposcopic examination may be adequate or inadequate. Colposcopic examination is adequate if the whole cervix is accessible and if the entire Transformation zone, together with SCJ can be visualized.
Inadequate colposcopic examination is the one where the cervix is not accessible or the entire cervix, including Transformation zone and SCJ cannot be visualized. Cervix cannot be reached in case of vaginal stenosis caused by neoplasia, irradiation, severe atrophia, previous surgery on the lower genital organs, due to pelvic tumors or congenital malformations (septum) and some dermatologic diseases such as Lichen planus. Colposcopic examination is also inadequate if the cervix is obscured by discharge or the blood.
If colpsocpic examination is inadequate the reason of inadequacy should be described.
Visibility of squamo-columnar junction
Squamo-columnar junction (SCJ) is the point where the two main cervical epithelial (columnar and squamous) meet each other. SCJ is a dynamic point, which changes its position depending on the age of women and estrogen level. In the prepubertal period SCJ is located in the endocervix. With puberty, it moves distally to ectocervix and usually remains visible during the whole reproductive period. After the menopause, SCJ moves proximally and remains in the endocervical canal during the whole postmenopausal life.
It is very important to explore SCJ entirely. SCJ is the most critical part of the cervix where majority of atypical lesions appear.
Squamo-columnar junction (SCJ) can be completely visible, partially visible or not visible. If squamocolumnar junction is not visible, colposcopic examination is considered unsatisfactory, because presence of abnormal lesion in the cervical canal can not be excluded by colposcopy. In these cases cytologic examination is more reliable.
Transformation zone types 1,2,3
Transformation zone is the area on the cervix where metaplasia takes place. Metaplasia is a process of replacement of the columnar epithelium by squamous epithelium. It starts from the original Squamo-columnar junction (which is the peripheral border of ectopia) and advances towards the external opening. SCJ is dynamic point which changes its position in relation of the estrogen level. Metaplasia causes SCJ to move gradually higher towards the endocervix in parallel with the increasing age.
Metaplasia is a normal, physiologic, irreversible process initiated by acid vaginal environment which stimulates reserve cells positioned on the basal membrane of columnar epithelium to differentiate not to columnar but to the squamous variant. Metaplasia is the most critical period for the onset of cervical abnormalities, because the immature metaplastic cells are susceptible to the effects of carcinogenic factors.
Metaplasia is usually categorized as immature and mature metaplasia. On colposcopic examination, this dynamic process of squamous metaplasia can be clearly observed and distinguished by three stages. The latter represents mature metaplastic squamous epithelium.
Thus the Transformation zone (TZ) is the whole area between the original squamo-columnar junction and the active (new) squamo-columnar junction
Type 1 TZ: ectocervical and fully visible
Type 2 TZ: has an endocervical component, but is fully visible
Type 3 TZ: has an endocervical component that is not visible and may have an ectocervical component
