Lost in translation: confusion on resection and dissection planes hampers the interpretation of pathology reports for perihilar cholangiocarcinoma

Abstract

In perihilar cholangiocarcinoma (PHC), interpretation of the resection specimen is challenging for pathologists and clinicians alike. Thorough and correct reporting is necessary for reliable interpretation of residual disease status. The aim of this study is to assess completeness of PHC pathology reports in a single center and assess what hampers interpretation of pathology reports by clinicians. Pathology reports of patients resected for PHC at a single expert tertiary center drafted between 2000 and 2018 were assessed. Reports were assessed regarding completeness, according to the guideline of the International Collaboration on Cancer Reporting (ICCR). A total of 146 reports were assessed. Prognostic tumor characteristics such as vasoinvasive growth and perineural growth were missing in 30/146 (34%) and 22/146 (15%), respectively. One or more planes were missing in 94/146 (64%) of the reports, with the periductal dissection plane missing in 51/145 (35%). Residual disease could be re-classified from R0 to R1 in 22 patients (15%). Reasons for R1 in these patients were the presence of a positive periductal dissection plane (n = 2), < 1-mm margin at the periductal dissection plane (n = 11), or liver parenchyma (n = 9). Completeness of reports improved significantly when drafted by an expert HPB pathologist. This study demonstrates that pathology reporting of PHC is challenging. Reports are frequently incomplete and often do not incorporate assessment of all resection planes and the dissection plane. The periductal dissection plane is frequently overlooked, but is a major cause of residual disease.

Short- and long-term outcomes after hemihepatectomy for perihilar cholangiocarcinoma: does left or right side matter?

“…Our reported R0-resection rate is lower compared to the R0-resection rates reported in literature, possibly due to our recent efforts to revise all pathology reports according to most recent guidelines. This action resulted in reclassification of residual disease based on a margin of <1 mm classified as R1, including all (circumferential, periductal dissection) planes (18).…”

“…Secondary outcomes were overall morbidity (including Clavien-Dindo grade 1 and 2), length of hospital stay and types of complications including bile leakage, liver failure and haemorrhage (all graded by the International Study Group of Liver Surgery (ISGLS) grading system, with grade B and C considered clinically relevant) (14)(15)(16). Recently, all pathology reports were revised according to the International Collaboration on Cancer Reporting (ICCR) guideline (17,18). According to this guideline, a margin of <1 mm at any resection plane, including the periductal dissection plane, was considered as residual disease.…”

Multidetector computed tomography assessment of vascular involvement in perihilar cholangiocarcinoma

“…The inability to evaluate vessels in initially unresectable patients is one of the major limitations of this study. Even for patients undergoing resection, the assessment of vascular involvement remains challenging for pathologists (14,15). As shown in literature, assessment of all relevant resection planes in PHC is often incomplete and the hepatic artery resection plane is most often lacking.…”

Surgical Therapy for Perihilar Cholangiocarcinoma: State of the Art

“…The secondary benefits of resection for pCCA may lie in optimizing biliary drainage and palliation. R0 resection is defined as tumor-free margins of ≥1 mm of the following planes: distal ductal margin (common bile duct), proximal margin (hepatic duct), portal vein resection (PVR) plane, hepatic artery resection plane, liver parenchyma resection plane, and periductal dissection plane [28]. Therefore, to properly assess the microscopic radicality of the resection, all resection and dissection planes need to be examined and described in the pathology reports.…”

“…Therefore, to properly assess the microscopic radicality of the resection, all resection and dissection planes need to be examined and described in the pathology reports. Roos et al [28] investigated a total of 146 reports in one institution, where one or more planes were missing in 64% of the reports. This resulted in a reclassified residual disease of 15% (22 patients were reclassified from R0 to R1), underscoring the importance of dedicated pathologists examining the specimen and widely implemented pathological assessment strategies.…”