Preventing errors in VIA Ė Errors in assessment Ė Errors in assessment of acetowhite areas
Thin acetowhite areas are the most common cause of diagnostic dilemmas and can be associated with various conditions, such as squamous metaplasia, condylomata, healing and regenerating epithelium, and inflammatory conditions. Although the primary aim of any cervical cancer screening test is to detect CIN2 or worse lesions, the criteria used for a positive VIA finding are such that the detection of a large number of CIN1 lesions is unavoidable.
Thin but opaque acetowhite areas that have well-defined regular margins and are located in the TZ and attached to the SCJ indicate the presence of low-grade cervical precancers. However, some of them may have focal high-grade lesions proximal to the SCJ. Such acetowhite areas should be reported as VIA-positive.
A thin acetowhite area around the external os and extending into the endocervical canal may be associated with a high-grade lesion within the canal. Such lesions are also VIA-positive.
Thin acetowhite areas located in the TZ, attached to the SCJ, and with sharp but angular or geographical margins, with or without satellite lesions, are indicative of HPV infections. However, such lesions could coexist with CIN and should be interpreted as VIA-positive.
Sometimes the thin acetowhite areas associated with inflammatory conditions are difficult to distinguish on VIA from those due to low-grade precancers. If such acetowhite areas have well-defined margins and are located within the TZ, they should be categorized as VIA-positive, and the woman should be referred for further evaluation.