Immunocytochemical analysis of p63 and 34βE12 in fine needle aspiration cytology specimens for breast lesions: a potentially useful discriminatory marker between intraductal papilloma and ductal carcinoma in situ.
Eighteen randomly selected cases of invasive breast carcinoma (IBC) of luminal type, two cases of in situ duct carcinoma (DCIS/DIN), and 20 specimens of normal and benign breast tissues were studied.All cases were immunostained for p63.
In carcinomas, p53 was expressed in 21.17% of carcinomas, whereas p63 was expressed only in poorly differentiated ductal carcinomas (11.76% of cases). p63-positive cells coexpressed 1A4 and 34betaE12, but not cytokeratin 7.
Invasive breast carcinomas were consistently devoid of nuclear p63 staining, with the exception of the two adenoid-cystic carcinomas, of the two ductal carcinomas with squamous metaplasia, and of 11 (4.6%) ductal carcinomas not otherwise specified, showing p63 immunoreactivity in a minor fraction (5-15%) of the neoplastic cells.