A postmenopausal woman presents with pruritic white lesions on the vulva. Punch biopsy of a representative area is obtained. Which of the following histologic findings is consistent with the diagnosis of lichen sclerosus?

Lichen sclerosus was formerly termed lichen sclerosus et atrophicus, but recent studies have concluded that atrophy does not exist. Patients with lichen sclerosus of the vulva tend to be older; they typically present with pruritus, and the lesions are usually white with crinkled skin and well-defined borders. The histologic appearance of lichen sclerosus includes loss of the rete pegs within the dermis, chronic inflammatory infiltrate below the dermis, the development of a homogenous subepithelial layer in the dermis, a decrease in the number of cellular layers, and a decrease in the number of melanocytes. Mechanical trauma produces bullous areas of lymphedema and lacunae, which are then filled with erythrocytes. Ulcerations and ecchymoses may be seen in these traumatized areas as well. Mitotic figures are rare in lichen sclerosus, and hyperkeratosis is not a feature. While a significant cause of symptoms, lichen sclerosus is not a premalignant lesion. Its importance lies in the fact that it must be distinguished from vulvar squamous cancer.