Benign hilar bile duct strictures resected as perihilar cholangiocarcinoma

Background Differentiation between perihilar cholangiocarcinoma (PHCC) and benign strictures is frequently difficult. The aim of this study was to investigate the incidence and long-term outcome of patients with tumours resected because of suspicion of PHCC, which ultimately turned out to be benign (malignancy masquerade). Methods Patients who underwent surgical resection with a diagnosis of PHCC between 2001 and 2016 were reviewed retrospectively. Results Among 707 consecutive patients, 685 had PHCC and the remaining 22 (3 center dot 1 per cent) had benign biliary stricture. All patients with benign disease underwent major hepatectomy, with no deaths. Preoperative histological assessment using bile duct biopsy or aspiration cytology had a high specificity (90 per cent), low sensitivity (62 per cent) and unsatisfactory accuracy (63 per cent). Despite the increasing use of histological assessment, the incidence of benign strictures resected did not decrease over time, being 0 center dot 9 per cent in 2001-2004, 4 center dot 0 per cent in 2005-2008, 3 center dot 8 per cent in 2009-2012 and 2 center dot 9 per cent in 2013-2016. The final pathology of benign strictures included IgG4-related sclerosing cholangitis (9 patients), hepatolithiasis (4), granulomatous cholangitis (3), non-specific chronic cholangitis (3), benign strictures after cholecystectomy (2), and a benign stricture possibly caused by parasitic infection (1). The 10-year overall survival rate for the 22 patients with benign stricture was 87 per cent, without recurrence of biliary stricture. Conclusion The incidence of benign strictures resected as PHCC as a proportion of all resections was relatively low, at 3 center dot 1 per cent. Currently, unnecessary surgery for suspected PHCC is unavoidable.