Diagnosis of bile duct metastasis from gastric cancer by endoscopic retrograde cholangiopancreatography combined with choledochoscopy: A case report

BACKGROUND: Bile duct metastasis from gastric cancer is a very rare secondary cancer, which can cause biliary obstruction. CASE SUMMARY: A 42-year-old male presented with right upper abdominal discomfort and jaundice after a total gastrectomy for poorly differentiated gastric adenocarcinoma. He underwent comprehensive laboratory tests and imaging examinations, and ultimately endoscopic retrograde cholangiopancreatography with choledochoscopy was performed. Stenoses were identified in the common hepatic duct and the common bile duct. Under choledochoscopic guidance, biopsy was taken from the bile duct tissue at the stenotic site. Then, a plastic stent was placed across the stenosis. Pathological examination with immunohistochemical staining confirmed poorly differentiated adenocarcinoma of the common bile duct. Following the procedure, the patient's liver function gradually improved, and his abdominal discomfort was also relieved. CONCLUSION: This case indicates the possibility of bile duct metastasis from gastric cancer and highlights the necessity of endoscopic retrograde cholangiopancreatography combined with choledochoscopy in patients with suspicious malignant biliary obstruction.