Primary carcinoma of the cystic duct: a case report and review of classifications

BACKGROUND The incidence of extrahepatic bile duct malignancies is about 2-3.6% of all gastrointestinal malignancies. Primary carcinoma of cystic duct is a rare condition comprising a fraction of all extrahepatic bile duct malignancies with less than 70 cases reported worldwide. Majority of these cases were reported from East Asia. There is paucity in such case being reported from Indian subcontinent. We present a case of primary carcinoma of the cystic duct encountered during laparoscopic cholecystectomy. CASE PRESENTATION A 65-year-old lady presented to us with symptomatic gall stone disease. Investigations revealed a distended gall bladder with multiple stones. Patient was taken up for laparoscopic cholecystectomy, during surgery a stony hard structure was found at cystic duct-common bile duct junction which was not amenable for clear dissection. Procedure was converted to open, and the patient underwent cholecystectomy with resection of common bile duct with Roux-en-Y hepaticojejunostomy and regional lymphadenectomy. Histopathological findings revealed it to be moderately differentiated adenocarcinoma of the cystic duct. CONCLUSION Primary carcinoma of cystic duct is a rare condition where early diagnosis can be difficult and if accidentally detected may add to surgeon's dilemma. Proper surgery with en-bloc resection of gallbladder, cystic duct, common bile duct, and regional lymphadenectomy is the mainstay of treatment. The prognosis of carcinoma of cystic duct is better than extrahepatic bile duct malignancies. The old classification system has outlived its time and is more rigid in definition which is not practical in advanced cases; the new classification systems of this century offer better insight into understanding the tumor characteristics and prognosis.