Since vulvar MLA and breast cancer have morphological similarities and similar aggressive behaviors, the criteria for diagnosing vulvar malignancy were defined by referring to breast carcinoma (12): in the absence of concurrent breast carcinoma, a primary adenocarcinoma of mammary-like glands of the vulva can be diagnosed when its morphological pattern is consistent with that of the breast carcinoma, with the presence of estrogen/progesterone receptors and positive markers such as CK 7 and GATA 3, which are common in breast cancers. The gene discussed is PGR; the disease is breast cancer.