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

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.