Objective. To establish gender clinical and morphological differences of the genital lichen sclerosus (LS) and to determine its malignant potential.

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

Results. In men, LS occurs at a younger age (median 45 years) than in women (59.5 years). The male LS is significantly more often accompanied by disordered keratinization, saw-toothed acanthosis, more pronounced plasmacytic, sometimes lichenoid, inflammatory infiltrate.

Conclusions. The keratinization disorder, epithelial hyperplasia severity and the immune response degree in the male genital LS is higher than in the female LS.