Simultaneously metastatic cholangiocarcinoma and small intestine cancer from breast cancer misdiagnosed as primary cholangiocarcinoma: A case report

BACKGROUND: Cholangiocarcinoma and small intestine cancer are common clinical malignancies, but metastatic cholangiocarcinoma and small intestine cancer are rare, especially simultaneous metastatic cholangiocarcinoma and small intestine cancer from breast cancer. Since the clinical presentation of metastatic cholangiocarcinoma and small intestine cancer does not differ from primary tumor, it may lead to misdiagnosis preoperatively. CASE SUMMARY: A 66-year-old woman was admitted to our hospital for further treatment due to abdominal pain and jaundice. Abdominal magnetic resonance imaging and magnetic resonance cholangiopancreatography showed an occupying lesion of the bile duct, considering a high possibility of primary bile duct tumor. Therefore, we performed a radical bile duct cancer surgery and cholecystectomy, and multiple tumors in the small intestine were found and removed during the surgery process. Postoperative pathology showed metastatic bile duct cancer and small intestine cancer from tumors in other parts. The patient underwent a right total mastectomy and axillary lymph node dissection because of right breast cancer 2 years ago. Combining with the immunohistochemical results, the patient was finally diagnosed as metastatic cholangiocarcinoma and metastatic small intestine cancer from breast cancer. Postoperatively, the patient received four cycles of chemotherapy and targeted therapy with docetaxel, capecitabine and trastuzumab. Unfortunately, the patient eventually died from tumor progression, thoracoabdominal infection, and sepsis 5 mo after surgery. CONCLUSION: Simultaneous metastatic cholangiocarcinoma and small intestine cancer from breast cancer are rare and the prognosis is extremely poor. Improving preoperative diagnostic accuracy is beneficial to avoid excessive surgical treatment. Treatment should be aimed at relieving biliary obstruction and abdominal pain, and then supplemented with chemotherapy and targeted therapy to control tumor progression and prolong the patient’s life.