Skip lesion of DIN (DCIS) in the nipple in a case of breast cancer.

The authors present a case of breast cancer with a skip lesion of DIN 1 (ductal carcinoma in situ [DCIS] grade 1) in the nipple, leaving the base of the nipple free of disease. During the surgical procedure of nipple-sparing mastectomy (NSM) a frozen section evaluation of the base of the nipple and areola complex is often carried out to ascertain absence of any intraepithelial (in situ) or invasive neoplasms that could lead to nipple recurrences if left behind. This case illustrates a situation where a frozen section would have given a false-negative prediction of nipple involvement if the patient had been selected for NSM. This case illustrates the need to adhere to strict criteria for selecting patients eligible for NSM and to consider the use of additional preoperative and intraoperative measurements and methods to refine the selection of candidates for NSM and enhance the oncological safety of the procedure.