Metastatic breast cancer mimicking a hilar cholangiocarcinoma: case report and review of the literature.

BACKGROUND/AIMS: Breast cancer is the most common tumor in women and the first cause of death for malignancy in the female population. Bile ducts are not among the common sites of metastasis from breast cancer; few cases of obstructive jaundice due to metastatic breast cancer have been described in the literature and they mostly resulted from widespread liver metastases that eventually involved the bile ducts. We report an exceptional case of metastatic infiltration of the extrahepatic bile ducts in absence of liver metastases. CASE PRESENTATION: A 56-year-old woman who had undergone a right mastectomy 13 years earlier due to infiltrating ductal breast cancer and had remained tumor free, presented at a follow-up examination with obstructive jaundice.Imaging (computed tomography, magnetic resonance and endoscopic retrograde cholangiopancreatography) scans showed features that were suggestive of a primary tumor of the extrahepatic bile duct. At surgery, the intraoperative findings were also those of a tumor of the bile duct, however, an histological examination showed no evidence of malignancy in the mucosa, but did shown an infiltration of the external wall from adenocarcinoma. Immunohistochemistry analysis demonstrated that the tumor was metastatic breast cancer. CONCLUSIONS: Indeterminate stenosis of the extrahepatic bile ducts should be examined with suspicion in women with a history of breast cancer, and bile duct metastases are to be considered among the possible diagnoses. A differential diagnosis from cholangiocarcinoma is of paramount importance and mainly relies on pathology.