Breast Cancer Arising from Accessory Mammary Tissue: A Case Report and Review of the Literature

Accessory breast tissue is a rare embryological anomaly, subject to the same pathological processes as orthotopic breast tissue, including malignancies. We report the case of a fifty-five-year-old, caucasien diabetic woman with a congenital supernumerary breast located in the right inframammary fold who presented with a progressively enlarging mass. Imaging revealed a suspicious five centimetres spiculated lesion classified as BIRADS 5 than the core needle biopsy confirmed the diagnosis of a grade III triplenegative invasive carcinoma. Prompt diagnosis and tailored multidisciplinary management are key to achieving favourable prognosis, and due to the rarity of this entity further studies are needed to establish standardized treatment protocols.