An uncommon intraepithelial malignant neoplasm of eccrine or apocrine origin, arising from the vulva. It usually affects post-menopausal women. In approximately 10-20% of the cases there is an associated anorectal, or urothelial carcinoma or a skin appendage adenocarcinoma identified. It presents as a red, eczematous lesion. Microscopically, it is characterized by the presence of the typical Paget cells which are large, round cells with abundant cytoplasm and prominent nuclei. [from
NCI]