system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Adult, Aged, Aged, 80 and over, Bile Duct Neoplasms, Bile Ducts, Extrahepatic, Bile Ducts, Intrahepatic, Cholangiocarcinoma, Diagnosis, Differential, Female, Humans, Male, Middle Aged, Neoplasm Staging, Retrospective Studies, Young Adult.
user
Is the concept of perihilar cholangiocarcinoma valid? Context: The term perihilar cholangiocarcinoma has been used for all tumours involving or requiring resection of the hepatic confluence. However, it does not distinguish between intrahepatic and extrahepatic hilar tumours, and has no clinicopathological basis. This retrospective study examined whether the concept of perihilar cholangiocarcinoma is valid clinically. Some 250 patients with perihilar cholangiocarcinoma were divided into extrahepatic (EHC, 167 patients) and intrahepatic (IHC, 83) groups based on tumour location. Clinicopathological data were compared between these groups. Liver, portal vein, venous and lymphatic invasion, and nodal metastasis were more common in IHCs than EHCs, whereas histological grade and incidence of perineural invasion were similar. IHCs were more advanced at the time of surgery; stage III or IV disease was found in 37.7 per cent of EHCs and 59 per cent of IHCs. Survival was marginally better for patients with EHCs than for those with IHCs (29.3 versus 20 per cent at 5 years; P = 0.057), but survival rates were similar for each tumour stage in the American Joint Committee on Cancer classification.
assistant
Combining EHC and IHC under the term perihilar cholangiocarcinoma is valid, as these tumours have comparable biological behaviour, with similar clinical management depending on stage and invasion. Final Decision: yes