T1b primary remnant cystic duct cancer following cholecystectomy: A case report

INTRODUCTION: Although primary cystic duct cancer is a rare entity, remnant cystic duct cancer is even more rare. We report a case of early cystic duct cancer following cholecystectomy. PRESENTATION OF THE CASE: A 81 year-old man complained temporary loss of appetite. He had underwent cholecystectomy for acute cholecystitis 5 years prior. Contrast enhanced computed tomography, magnetic resonance image and endoscopic ultrasonography showed remnant cystic duct tumor with protrusion to common bile duct. Endoscopic retrograde cholangiography revealed defect of contrast medium around confluence of the remnant cystic duct and common bile duct. We performed step biopsy by using forceps which revealed adenocarcinoma. Based on these findings, extrahepatic bile duct and remnant cystic duct resection were performed. The histopathology showed adenocarcinoma, pap > tub2, filling in remnant cystic duct, 30 mm in size but showed no lymphovascular or perineural invasion, no lymph node metastasis and negative surgical margin, and was classified as pT1bN0M0. CONCLUSION: This is a rare case of primary carcinoma of remnant cystic duct cancer which is detected during computed tomography follow up for hepatic cell carcinoma recurrence. We confirmed remnant cystic duct cancer and its superficial extension to common bile duct with endoscopic ultrasonography and intraductal ultrasonography. Proper curative surgery was performed.