Management of ipsilateral supernumerary nipple at time of breast cancer diagnosis.

Supernumerary breast components occur predominantly between the breast and umbilicus. Carcinoma of this ectopic, or accessory breast tissue (ABT), is exceedingly rare, accounting for <1% of breast cancer cases. Historically, ectopic breast carcinoma was considered aggressive with poor outcome. In 1995, Evans et al reported 90 cases spanning from 1929 to 1993 with a 9.4% survival beyond 4 years. More contemporary studies reveal improvement in both treatment and survival. There is currently no consensus on whether prophylactic excision of an ipsilateral supernumerary nipple at the time of initial breast cancer diagnosis is necessary. The following describes a patient with an ipsilateral tumor uniquely located within her supernumerary nipple 5 years after mastectomy.