Primary Breast Carcinoma in Ectopic Breast Tissue in the Suprapubic Region Presenting as a Subcutaneous Nodule: A Case Report and Review of the Literature.

Ectopic breast tissue (EBT) is an uncommon congenital condition resulting from incomplete involution of the milk line. Primary carcinomas arising in EBT have been reported in a small number of cases, most frequently in the axilla, but they may occur anywhere along the mammary line. Here, we present the case of a 69-year-old woman who presented with an asymptomatic subcutaneous nodule located at the end of a Pfanneistein's laparotomy scar in the suprapubic region. Histopathological examination revealed invasive ductal carcinoma, compatible with no special type, originating from EBT. The patient underwent wide local excision of the lesion with clear margins, followed by adjuvant treatment with letrozole. This case highlights the importance of timely diagnosis and emphasizes the significance of recognizing the rare presentation of primary breast carcinoma in EBT. Early detection and appropriate treatment, including surgical intervention and targeted therapy, are essential for optimizing patient outcomes in such cases.