Objective: The aim of this study was to determine whether the premalignant change in lichen sclerosus (LS) could be identified with immunohistochemical analyses.
Study design: Eight cases of histologically diagnosed vulvar LS, which showed, after a period of 10 months-9 years, an evolution to carcinoma of the vulva that was histologically documented, were compared with 8 cases of vulvar LS, for which follow-up information was available for at least 9 years. The proliferative index and the expression of tumor suppressors p16 and p53 were analyzed.
Results: The difference of MIB1 labeling index of evolving or unchanged LS cases was significant (P = .005). The difference in the p53 of evolving or unchanged LS cases shows a trend towards association (P = .08). Both LS cases (evolving or unchanged) did not show p16 positive staining.
Conclusion: The evaluation of MIB1 and p53 may identify those vulvar LS cases with a high likelihood of evolving into squamous cell carcinoma, which would need careful periodic checks or adjunctive biopsies. The study must be confirmed by a larger number of cases to substantiate this observation.