[Let's continue to differentiate VaIN 2 from VaIN 3: a study on the progression of a series of 54 cases of VaIN 2].

Objective : Vaginal intraepithelial neoplasias (VaIN) are rare pre-cancerous lesions of the female genital tract caused by human papillomaviruses (HPV) (1). Their risk of progression to actual vaginal cancer is estimated between 3% and 12% (2, 5). Since the new 2020 terminology of the World Health Organization (WHO) on high-grade VaIN, gathering VaIN 2 and 3, the recommended management is the same (6). However, the progression of these histopathological entities would be very different, which is why we wanted to study the outcome of VaIN 2 cases followed in our department, depending on whether the management was active through laser destruction, Imiquimod, or surgical excision, or if close monitoring was preferred. Materials and Methods : We conducted a retrospective monocentric study between 1990 and 2024. All patients diagnosed with VaIN 2 and followed for at least 2 years were included. Results : Fifty-four patients were included, one-third of whom were initially monitored, and the average follow-up duration was 54.8 ± 26.8 months. The average age at diagnosis was 52.6 ± 15.9 years, with a history of smoking found in 40% of the patients, immunosuppression in a quarter of them, and 22% of the patients had an HPV 16 or 18 infection. A favorable outcome was found in 66.7% of the monitored cases and in 81.8% of the actively treated cases. There was no significant difference in the progression profiles with p equal to 0.14. There was also no significant difference in event-free survival with p equal to 0.10. Conclusion : Expectant management does not appear to be associated with an increased risk of unfavorable progression compared with ablative treatment. It therefore seems reasonable to propose an appropriate initial surveillance strategy. VaIN 2 lesions appear to have a predominant rate of spontaneous regression, which may call into question the relevance of grouping all high-grade VaIN lesions together.