Composite small cell and mucinous carcinoma originating from the intrahepatic bile duct: report of a case

Abstract

The biliary tract is a very rare site for the occurrence of extrapulmonary small cell carcinoma. A 68-year-old Japanese female was being followed up for autoimmune hepatitis, and was referred to our hospital because segmental intrahepatic bile duct dilation was found on routine imaging studies, suggesting intrahepatic cholangiocarcinoma. She underwent left lobectomy of the liver and concomitant resection of the caudate lobe. Microscopic examination of the explanted liver showed a primary composite tumor comprising small cell and mucinous carcinomas that originated in the intrahepatic bile duct. Further immunohistochemical studies, including cytokeratin-19 and chromogranin-A staining, showed the two cellular components of the tumor to have similar characteristics. The amphicrine properties indicated that the tumor had a monoclonal origin but with biphenotypic differentiation, which was responsible for the histogenesis of this tumor.

Presence of Cytokeratin 19-Expressing Cholangiocarcinoma-Like Tumour in a Liver Metastatic Lesion of Rectal Neuroendocrine Tumour

“…Furthermore, amphicrine tumours are thought to represent another phenotype of composite tumours and are characterised by the appearance of dual neuroendocrine and glandular features in the same cell. This type of tumour is extremely rare, with only a few such reports in the stomach, pancreas, and liver [ 4 , 10 , 11 ].…”

Rare Malignant and Semimalignant Epithelial Neoplasms of the Biliary Tract

“…Very rare cases of hepatocellular carcinomas can contain a small cell tumor component with neuroendocrine features, the HCC component expressing hepatocyte markers and AFP, and the SCC component reactive for chromogranin A and synaptophysin (Yamaguchi et al 2004;Garcia et al 2006;Yang et al 2009). Composite small cell and mucinous adenocarcinoma can also originate from intrahepatic bile ducts (see below; Ikegami et al 2013). Combined SCC and adenocarcinomas have been observed in the stomach (Jang et al 2007) and the colon (Scherwitz et al 2002) and found to have metastasized to the liver.…”

“…Histology and immunohistochemistry are the same as with small cell gallbladder carcinomas (Kuraoka et al 2003). Mucinous adenocarcinoma of intrahepatic bile ducts can rarely be combined with small carcinoma, the tumors showing CK 19-positive and chromogranin A-positive cell populations (Ikegami et al 2013). Small cell carcinoma of the bile ducts exhibits an aggressive biology (Jeon et al 2006), the longest reported survival after multidisciplinary management being 23 months (Okamura et al 2009).…”