Transformation zone types: a call for review of the IFCPC terminology to embrace practice in low-resource settings

Abstract

Most cervical cancers develop in the transformation zone (TZ). Type 3 TZs, where the full circumference of the squamocolumnar junction (SCJ) is not visible pose problems during cervical screening with visual inspection methods, as (pre)cancerous lesions may be missed. Several practical strategies can be implemented to convert type 3 TZs into TZ 1 or TZ 2, including the use of an endocervical speculum or hygroscopic cervical dilators, opening the vaginal speculum more widely, skillful use of cotton-tipped applicators, performing colposcopy in midcycle, and use of oral or vaginal misoprostol and estrogen to 'ripen' the cervix. With the 2011 International Federation for Cervical Pathology and Colposcopy (IFCPC) terminology, settings with better resources to manipulate the cervix for a better view of the endocervical canal may assign patients to different categories from those in low-resource settings during a colposcopic examination. Here, we propose a colposcopic revision to the current IFCPC classification by segregating TZ 2 according to the extent of endocervical involvement and TZ 3 according to whether any attempt is made to open the endocervical canal, if such attempt(s) were successful, and the extent to which the practitioner can visualise parts of the uterine cervix beyond the border of the SCJ in the endocervical canal. In this proposed reclassification, TZ 2A has no part of the SCJ extending beyond 5 mm into the endocervical canal, whereas TZ 2B has part or all of the SCJ extending beyond 5 mm into the endocervical canal. TZ 3 is further subclassified into TZ 3A if the practitioner does not attempt to open the endocervical canal or the endocervical canal is opened, but not beyond 5 mm and TZ 3B if the full circumference cannot be visualised after opening the endocervical canal beyond 5 mm. We believe this revision will improve and better standardise the classification of TZ types, with huge implications for practice in low-resource settings, due to limited options for referral and treatment, to reduce the risk of missed cervical cancers and suboptimal treatment resulting from ablating lesions that extend too far into the endocervical canal.

Keywords: colposcopy; early detection of cancer; transformation zone; uterine cervical neoplasm; visual inspection with acetic acid.

Figure 1.. (a): No attempt made to open the endocervical canal. The entire circumference of the SCJ is not visible. This will be TZ 3A under the proposed reclassification. (b): Same woman. The entire circumference of the SCJ is visible using an endocervical speculum. The SCJ extends more than 5 mm into the endocervical canal. This will be TZ 2B under the proposed reclassification. Images courtesy CCPTC, Battor.

Figure 2.. (a): No attempt made to open the endocervical canal. The entire circumference of the SCJ is not visible. This will be TZ 3A under the proposed reclassification. (b): Same woman. The entire circumference of the SCJ is visible after pushing a cotton swab into the posterior fornix of the vagina. The SCJ extends less than 5 mm into the endocervical canal. This will be TZ 2A under the proposed reclassification. Images courtesy CCPTC, Battor.

Figure 3.. The JHPIEGO [16] visual inspection of the cervix flash card set ((A): front of flashcard 1 in the deck and (B): back of flashcard 1 in the deck) considers this woman a good candidate for cryotherapy. Under the proposed reclassification, this cervix would be TZ type 3A and would not qualify for ablative treatment. To be eligible for ablative treatment, an attempt should be made to see the full SCJ clearly in the endocervical canal (TZ 2A/2B) and the probe must completely cover the lesion/TZ during ablation. Source: Reproduced with permission from JHPIEGO Corporation.