Analysis of Microscopic Tumor Spread Pattern According to Gross Morphology in Bile Duct Cancer

Abstract

Introduction: Surgical resection is the only curative therapy in the extrahepatic bile duct (EHBD) cancer but guideline on optimal resection margin is not established. Therefore, the purpose of this study is to analyze the pattern of microscopic tumor spread and its length according to gross morphology and to suggest optimal resection margin in EHBD cancer. Methods: From 2007 to 2010, 79 patients with EHBD cancer who underwent curative resection at Seoul National University Hospital were reviewed and analyzed. Pathologic findings including spread pattern of the tumor and its length were reviewed by one specialized pathologist. Results: Mucosal and mural/perimural spread was seen in 59 (37.3%) and 99 (62.3%) cases, respectively. Gross morphology were classified as papillary (n=13), nodular/nodular infiltrative (n=43), and sclerosing type (n=23) and spread pattern correlated with gross morphology (p < 0.001). In papillary type, 80.8% showed mucosal spread while sclerosing type had 16.9%. Mean length of tumor spread of each gross type were 4.5 ± 6.3mm, 1.8 ± 6.4mm, and 6.4 ± 6.7mm (p = 0.004), and 90 percentile of the length of tumor spread were 15.6mm, 10.0mm, 15.6mm, respectively. Conclusions: The pattern of tumor spread correlated with gross morphology and sclerosing type showed the longest tumor spread. Optimal resection margin in EHBD cancer should be 15mm in papillary/sclerosing type and 10mm in nodular/nodular infiltrative type.