Signet ring cell carcinoma of the extrahepatic bile duct

Most tumors affecting the extrahepatic bile duct are adenocarcinomas; the other histologic types occur only rarely. We herein report the extremely rare case of signet ring cell carcinoma (SRCC) originating from the extrahepatic bile duct. A 55-year-old man was hospitalized for jaundice and pruritus. Computed tomography and positron emission tomography suggested the presence of distal extrahepatic bile-duct cancer. He underwent a pylorus preserving pancreaticoduodenectomy. A histologic study confirmed a signet ring cell neoplasm of the distal common bile duct. Because the upper resection margin was invaded by the tumor, he received postoperative concurrent chemoradiotherapy and four cycles of chemotherapy. The patient has survived with no evidence of recurrence for 2 years. This is the second case of primary SRCC of the distal extrahepatic bile duct reported in the literature; further reports of cases are warranted to determine the nature of SRCC in the extrahepatic bile duct.