The microscopic extent of the disease is often greater than is clinically detectable. Vulvar Paget's disease. Note erythematous lesion on left labium majus. Histology Microscopically, the lesion is identified by the presence of large, pale, mucin-containing epithelial cells scattered singly or in small nests within the epidermis. Vulvar Paget's disease.
Tumor cells with abundant pale cytoplasm infiltrate the epidermis individually and in nests.
Untreated, vulvar Paget's disease runs a slowly progressive, indolent course. Prognosis depends on whether there is an associated invasive tumor.