Evaluation and clinical correspondence to surgical margins in biliary tract cancer

Abstract

Surgical margins in biliary tract cancer include bile duct stumps and radial margin. Even an experienced pathologist may have difficulty diagnosing bile duct stump because of epithelial regeneration/reactive atypia due to inflammation caused by biliary drainage tube, difficulty in the evaluation of frozen sections, and appendage/periductal glands and ducts in the wall mimicking invasive cancer. The outcome for positive invasive cancer in the bile duct stump is poor, and the significance of additional resection is controversial. A positive carcinoma in situ has the same short-term outcomes as a negative margin but may cause recurrence in the medium to long term. In early-stage cholangiocarcinoma without lymph node metastases, additional resection for carcinoma in situ may improve survival. Securing a sufficient margin on the radial margin in the hepatic hilum and hepatoduodenal ligament due to the proximity of the bile duct and blood vessel is challenging, and the outcomes are reported to be poor if the radial margin is positive for invasive cancer. Although reports on the separation of carcinoma in situ and invasive cancer for postoperative treatment in patients with positive resection margins are absent with limited evidence, expectations for chemotherapy and chemoradiotherapy exist.