Intraductal Components of Breast Cancer Spread to the Areola: A Case Report.

Ductal spread of breast cancer sometimes causes nipple recurrence, but very rarely causes recurrence in the areola. A 65-year-old woman visited our hospital for a detailed examination of a newly developed small induration in the right areola, 15 years after undergoing nipple-preserving surgery for luminal-type breast cancer. The patient had also developed contralateral luminal-type breast cancer six years after the first operation and had undergone nipple-preserving surgery again. MRI at the second operation had shown no abnormalities in the right nipple-areolar complex (NAC). On her first visit to our hospital, we palpated a firm induration in the right areola. Ultrasound showed a mass in the areolar skin with suspected dermal disruption. Core needle biopsy showed invasive cancer cells on pathological examination. The patient, therefore, underwent resection of the NAC with adequate safety margins. Postoperative pathological study showed luminal-type invasive cancer cells mainly growing in the areolar skin with minimal fat invasion, and two solid luminal-type non-invasive ductal cancers (DCISs): one near the areolar skin and the other deeper in the subcutaneous fat tissue around the NAC. The two DCISs had small, discontinuous mammary duct structures around them with linear fibrous components, i.e., the presumed Cooper ligament. The non-malignant mammary duct structures extended toward the areola, and some of them were located closer to the areolar skin than the DCIS focus located near the skin. We, therefore, judged that this areolar recurrence was caused by DCIS that had been present in the mammary ducts extending toward the areola. Breast surgeons should note that the intraductal components of breast cancer can have ductal spread toward the areola and should resect the Cooper ligament when it is identified around the NAC during the operation to avoid this type of areolar recurrence.