Abstract
Introduction
Signet ring cell carcinoma (SRCC) of the biliary system is extremely rare and its clinicopathological features and impact on prognosis are not well known. We report the extremely rare case of SRCC originating from the extrahepatic bile duct.
Case Report
We present a 76-year-old female who had elevated liver enzymes noted on routine laboratory test. Abdominal imaging revealed a polypoid mass within the central bile duct, located above the level of pancreatic head with proximal intrahepatic duct dilatation with no significant lymphadenopathy or ascites. Total bilirubin was normal, alanine transaminase level was 163 IU/L, and aspartate aminotransferase was 55 IU/L. The patient underwent common bile duct excision with cholecystectomy. The specimen showed a 3.3-cm centrally located tan polypoid lesion in the common bile duct with adjacent firm lymph node. Microscopic examination of the lesion revealed sheets of tumors cells with signet ring cell morphology underlying benign biliary epithelium. The lymph node was completely replaced by neoplastic cells. The neoplastic cells were diffusely positive for CDX2 and focally positive for CK7 and CK20. The histomorphology and immunophenotype are consistent with poorly differentiated adenocarcinoma with signet ring cell type.
Conclusion
SRCC of the extrahepatic bile duct is a histologically distinct entity classified by the World Health Organization, but it is very rare. To best of our knowledge, only five cases of SRCC of the extrahepatic bile duct have been reported in the English literature.
A CASE REPORT OF ADENOENDOCRINE CELL CARCINOMA OF THE EXTRAHEPATIC BILE DUCT
