Hypertrophic lichen sclerosus with dyskeratosis and parakeratosis--a common presentation of vulvar lichen sclerosus not associated with a significant risk of malignancy.

Epithelial hyperplasia, individual necrotic keratocytes, and parakeratosis are common findings in lichen sclerosus. When those changes are prominent, they may pose diagnostic problems, especially because such lesions often show no or only minimal sclerosis. Necrotic keratocytes are often numerous and are found in all reaches of the epidermis, presenting themselves as eosinophilic globules with or without remnants of pyknotic nuclei. Because those changes tend to be accentuated focally above dermal papillae, they often give rise to narrow columns of parakeratosis in the overlying cornified layer. Within those columns, individual necrotic keratocytes with pyknotic nuclei are preserved as distinct dyskeratotic parakeratotic cells. That constellation of findings is fairly characteristic of hypertrophic lichen sclerosus. It was found, at least subtle and focally, in 14 of 70 consecutive biopsy specimens of lichen sclerosus, most of which came from the vulva of elderly women. Although similar cases have been described as differentiated vulvar intraepithelial neoplasia (VIN) in the literature, there was no significant nuclear atypia, no crowding of nuclei, and no significant mitotic activity in any of those lesions. Follow-up of at least 5 years in 8 patients revealed no development of squamous cell carcinoma. Hypertrophic lichen sclerosus with dyskeratosis and parakeratosis seems to be a relatively common presentation of vulvar lichen sclerosus not associated with a significant risk of malignancy.