Signet-ring cell carcinoma of the distal common bile duct: report of a case.

Signet-ring cell carcinoma (SRCC) of the extrahepatic bile duct is a histologically distinct entity classified by the World Health Organization, in which cells containing intracytoplasmic mucin displacing the nucleus predominate.1 SRCC of the gastrointestinal tract is most commonly found in the stomach, and the impact of this histology on the prognosis is controversial.2,3 Well to moderately differentiated adenocarcinoma is the most common histologic type and complete resection is the only potentially curative therapy for distal bile duct cancer.4 However SRCC of extrahepatic bile duct is extremely rare, so its clinico-pathological features and impact on the prognosis are not well known. To the best of our knowledge, only three cases of SRCC of the extrahepatic bile duct have been reported in the English literature.5,6,7 Herein, we present a case of SRCC originating from the epithelium of the distal extrahepatic bile duct.