Objective. To establish the gender morphological differences in the precancerous lesions on the background of lichen sclerosus (LS) and the histological features with high malignant potential.

Materials and methods. Biopsy and surgical materials of penis (n=61) and vulva (n=83) with LS diagnosis verified morphologically were examined. The male and female LS clinical and morphological characteristics were compared.

Results. It has been established that the ratio of male LS with associated precancerous lesion (6.8%) is higher than female (2.4%) ratio. For the first time, a reliable association of such lesions on the background of early LS in men has been revealed.

Conclusion. A higher ratio of the precancerous lesions co-existing with LS suggests that the malignant potential of this dermatosis in men may be higher than in women.