Triple-Negative Papillary Carcinoma of the Breast: A Case Report.

Papillary carcinoma is a rare form of breast malignancy, representing only a small percentage of newly diagnosed breast cancers. Bloody nipple discharge is the most consistent symptom reported among patients. These lesions are visualized histologically as fibrovascular cores lined with proliferating neoplastic epithelial cells. Papillary breast carcinomas are characterized by estrogen receptor (ER), progesterone receptor (PR), and/or human epidermal growth factor receptor 2 (HER2) positivity, allowing for targeted therapeutic approaches with favorable outcomes. Triple-negative papillary carcinoma (TNPC) is a rare variant that lacks this characteristic hormone receptor expression, creating a unique challenge in diagnosis and management. Here, we highlight the case of a 43-year-old asymptomatic female with TNPC following an abnormal screening mammogram that revealed a suspicious mass in the left breast. Surgical excision with clear margins remains the cornerstone of treatment, with adjuvant chemotherapy considered for high-risk cases. As there is limited evidence on the efficacy of targeted therapies and hormone-based treatments, this case analyzes the diagnostic criteria, therapeutic options, and prognosis of TNPC to prompt further investigation into specific treatment strategies.