Practical review for diagnosis and clinical management of perihilar cholangiocarcinoma.

Cholangiocarcinoma (CCC) is the most aggressive malignant tumor of the biliary tract. Perihilar CCC (pCCC) is the most common CCC and is burdened by a complicated diagnostic iter and its anatomical location makes surgical approach burden by poor results. Besides its clinical presentation, a multimodal diagnostic approach should be carried on by a tertiary specialized center to avoid miss-diagnosis. Preoperative staging must consider the extent of liver resection to avoid post-surgical hepatic failure. During staging iter, magnetic resonance can obtain satisfactory cholangiographic images, while invasive techniques should be used if bile duct samples are needed. Consistently, to improve diagnostic potential, bile duct drainage is not necessary in jaundice, while it is indicated in refractory cholangitis or when liver hypertrophy is needed. Once resecability criteria are identified, the extent of liver resection is secondary to the longitudinal spread of CCC. While in the past type IV pCCC was not considered resectable, some authors reported good results after their treatment. Conversely, in selected unresectable cases, liver transplantation could be a valuable option. Adjuvant chemotherapy is the standard of care for resected patients, while neoadjuvant approach has growing evidences. If curative resection is not achieved, radiotherapy can be added to chemotherapy. This multistep curative iter must be carried on in specialized centers. Hence, the aim of this review is to highlight the main steps and pitfalls of the diagnostic and therapeutic approach to pCCC with a peculiar attention to type IV pCCC.