Page 6 - Read Online

Pedica et al. Hepatoma Res 2021;7:71 Hepatoma Research
DOI: 10.20517/2394-5079.2021.89

Review Open Access

Pathology and molecular pathology of

cholangiocarcinoma

Federica Pedica, Greta Grassini
Department of Experimental Oncology, Pathology Unit, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.

Correspondence to: Dr. Federica Pedica, Department of Experimental Oncology, Pathology Unit, IRCCS San Raffaele Scientific
Institute, via Olgettina 60, DIBIT 2, San Gabriele Building, Milan 20132, Italy. E-mail: pedica.federica@hsr.it

How to cite this article: Pedica F, Grassini G. Pathology and molecular pathology of cholangiocarcinoma. Hepatoma Res
2021;7:71. https://dx.doi.org/10.20517/2394-5079.2021.89

Received: 30 Jun 2021 First Decision: 16 Aug 2021 Revised: 31 Aug 2021 Accepted: 10 Sep 2021 Published: 5 Nov 2021

Academic Editor: Giuliano Ramadori Copy Editor: Xi-Jun Chen Production Editor: Xi-Jun Chen

Abstract
Biliary tract cancers are a wide group of heterogeneous neoplasms of the biliary tree, composed of intrahepatic
cholangiocarcinoma perihilar bile duct cancer and distal bile duct cancer, according to location. The variability in
location reflects the different morphologies and molecular alterations. In particular, intrahepatic peripheral mass
forming cholangiocarcinoma is represented by the “small duct type” cholangiocarcinoma, which is different from
the “large duct type” cholangiocarcinoma that, although intrahepatic, behaves similar to extrahepatic bile duct
cancers, perihilar and distal ones. Recently, molecular targetable alterations, mainly FGFR2 fusions and IDH1
mutations, have been described, mostly in the intrahepatic “small duct type” subgroup and have opened the way,
together with rarer targetable alterations, for personalisation of therapy also in these aggressive neoplasms.

Keywords: Biliary tract cancer, cholangiocarcinoma, molecular pathology, WHO classification, targetable
alterations

BACKGROUND
Biliary tract cancer is a heterogeneous and very aggressive group of neoplasms that includes intrahepatic
cholangiocarcinoma and extrahepatic bile duct cancer. It arises in different clinical contexts and often in
non-cirrhotic livers, without clear aetiology. It can be found on surgical specimens associated with
preneoplastic lesions that at least partially resemble the pancreatic counterpart. Recently, the morphological
classification of this neoplasm has been improved and finds confirmation in the molecular profile. In fact,

© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing,
adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as
long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and
indicate if changes were made.

www.hrjournal.net