PGR and breast carcinoma: Histology criteria for the diagnosis include (1) a morphology consistent with breast carcinoma; (2) positive estrogen and/or progesterone-receptor expression on immunohistochemical staining; (3) immunostaining positive for additional common breast cancer-associated markers including carcinoembryonic antigen, CK7, and mammoglobin; and (4) presence of a non-neoplastic breast tissue or carcinoma in situ component [5].