Analysis of microscopic tumor spread patterns according to gross morphologies and suggestions for optimal resection...

Surgical resection is the only curative treatment for extrahepatic bile duct (EHBD) cancer, but guidelines for optimal resection margins have not yet been established. Therefore, the purpose of this study is to analyze the patterns of microscopic tumor spreads and their lengths according to gross morphology and to suggest optimal resection margins for EHBD cancer.

A total of 79 patients with EHBD cancers who underwent curative resection at Seoul National University Hospital between 2007 and 2010 were reviewed. Pathologic findings were reviewed by a single specialized pathologist.

Mucosal and mural/perimural spreads were seen in 37.3 and 62.3 %, respectively. The mean length of tumor spreads in the papillary (n = 13), nodular/nodular infiltrative (n = 43), and sclerosing types (n = 23) were 4.5 ± 6.3, 1.8 ± 6.4, and 6.4 ± 6.7 mm, respectively. Spread patterns correlated with gross morphologies (P < 0.001). The lengths of tumor spreads at the 90th percentile were 15.6, 10.0, and 15.6 mm, respectively.

The patterns of tumor spreads correlated with gross morphologies. Optimal resection margins in EHBD cancers should be 16 mm in the papillary and sclerosing types and 10 mm in the nodular/nodular infiltrative type.