An Atypical Presentation of Invasive Breast Carcinoma

Ectopic breast tissue (EBT) is found in no more than 6% of the population. The axilla is the most common location.We report a case of a 43-year-old woman that showed a painless small lump on her right anterior axillary line adjacent to the axilla, for three years. On ultrasound it corresponded to a growing unspecific hypochogenic subcutaneous nodule. A core biopsy was performed and the histologic diagnosis was that of an invasive lobular breast carcinoma in an aberrant EBT. A locoregional staging by magnetic resonance (MR) was performed showing no other lesions. Patient underwent wide local excision of the lesion followed by radiotherapy and hormone therapy. This article underlines the possibility of presentation of EBT as an invasive breast carcinoma, emphasizing its clinical and imaging features and the importance of its prompt recognition for a timely treatment