Thyroid-Like Cholangiocarcinoma: Histopathological, Immunohistochemical, In-Situ Hybridization and Molecular Studies on an Uncommon Emerging Entity. (December 2021)

• Record Type: Journal Article
• Authors: Hissong, Erika; Chiu, Kenrry; Park, Hyeon; Solomon, James; Song, Wei; Jessurun, Jose
• Is Part Of: International journal of surgical pathology. Volume 29:Number 8(2021)
• Page Start: 920
• Page End: 925
• Publication Date: 2021-12
• Subjects: cholangiocarcinoma -- thyroid-like pattern -- albumin in-situ hybridization -- molecular characterization; Pathology, Surgical -- Periodicals; 617.07
• DOI: 10.1177/10668969211013906
• Languages: English
• ISSNs: 1066-8969

Abstract

Thyroid-like cholangiocarcinoma is a very uncommon variant of peripheral-type cholangiocarcinoma. To date, only 4 prior cases have been reported. The molecular features of this tumor have not been described. We report a case of a 60-year-old woman with a tumor that evolved over a period of 10 years. A left hepatectomy specimen showed an 11 cm tumor that on histology exhibited areas reminiscent of a thyroid tumor with follicular and insular features which were positive on immunohistochemistry for cytokeratin 7 and in-situ hybridization for albumin. A detailed molecular analysis failed to show mutations common to cholangiocarcinomas but revealed frameshift mutations in 2 chromatin-remodeling genes, CREBBP and KMNT2A. This case confirms that thyroid-like cholangiocarcinoma is a histologic variant of this tumor that is associated with relatively low growth. As most cholangiocarcinomas, it is diffusely positive for cytokeratin 7 and albumin by in-situ hybridization. Given its rarity, the molecular alterations in this specific histologic subtype remain to be fully elucidated.