Background
Primary neuroendocrine carcinoma of the breast (NECB) is an exceptionally rare malignancy, accounting for less than 0.1% of breast cancers and less than 1% of neuroendocrine tumors. Although distant metastases—particularly to the liver—are described, pancreatic involvement remains extraordinarily uncommon. To date, the literature contains only 1 previously reported case of primary NECB presenting with synchronous pancreatic and liver metastases, underscoring the diagnostic and management challenges this presentation poses for breast surgeons and oncologists.
Materials and Methods
A review of the peer-reviewed literature was performed using PubMed/MEDLINE and reference-list screening to identify publications describing primary breast neuroendocrine tumors and neuroendocrine carcinomas. Extracted data included tumor differentiation, hormone receptor status, metastatic patterns, diagnostic criteria supporting breast origin, and reported management strategies. Our institutional case was reviewed and integrated to illustrate points of diagnostic complexity and management decision-making.
Results
Primary NECB demonstrates aggressive clinical behavior with high rates of distant metastasis. Published series report distant disease in up to 83% of patients within 4 years and median overall survival of approximately 32 months in metastatic cohorts. The most commonly reported metastatic sites include liver, bone, lung, lymph nodes, and brain. In contrast, synchronous pancreatic and hepatic involvement remains exceptionally rare, with only a single prior case identified in the literature. Diagnosis of NECB requires positive immunohistochemical staining for neuroendocrine markers and exclusion of an extramammary primary, which is particularly critical in the setting of pancreatic disease. Management strategies remain heterogeneous and are largely extrapolated from neuroendocrine carcinoma paradigms, including platinum-based chemotherapy for high-grade tumors, incorporation of endocrine therapy in hormone receptor–positive disease when feasible, and limited surgical intervention primarily for diagnostic or palliative purposes. Our patient, a 45-year-old woman, presented with a large breast mass and rapidly progressive visceral disease including extensive liver metastases and pancreatic infiltration causing biliary obstruction, illustrating the aggressive nature of this rare presentation.
Conclusions
Primary NECB with synchronous pancreatic and liver metastases is an extraordinarily rare and highly aggressive disease phenotype. For breast surgeons, early recognition, rigorous confirmation of breast origin, and close multidisciplinary collaboration are essential, as management is driven by tumor biology and systemic therapy rather than surgical intervention. Continued reporting of such cases is critical to improving understanding and care of this uncommon breast cancer subtype.
