Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 28, 2018; 24(12): 1332-1342
Published online Mar 28, 2018. doi: 10.3748/wjg.v24.i12.1332
Intraoperative frozen section diagnosis of bile duct margin for extrahepatic cholangiocarcinoma
Takayuki Shiraki, Hajime Kuroda, Atsuko Takada, Yoshimasa Nakazato, Keiichi Kubota, Yasuo Imai
Takayuki Shiraki, Keiichi Kubota, Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi 321-0293, Japan
Hajime Kuroda, Atsuko Takada, Yoshimasa Nakazato, Yasuo Imai, Department of Diagnostic Pathology, Dokkyo Medical University, Tochigi 321-0293, Japan
Author contributions: Shiraki T and Kuroda H contributed equally to this work; Shiraki T collected clinical information; Kuroda H and Imai Y reviewed the pathological diagnosis; Shiraki T, Kuroda H, and Imai Y analyzed the data and wrote the manuscript; Takada A and Nakazato Y made critical revisions of the manuscript; Kubota K and Imai Y designed the study; Imai Y gave the final approval of the manuscript for publication.
Supported by JSPS KAKENHI (No. JP16K08695) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
Institutional review board statement: This study protocol was approved by the ethical review board in the Dokkyo Medical University Hospital (DMUH: R-2-21).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The authors declare no competing interests related to this study.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Yasuo Imai, MD, PhD, Department of Diagnostic Pathology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi 321-0293, Japan. ya-imai@dokkyomed.ac.jp
Telephone: +81-282-872130 Fax: +81-282-861681
Received: February 13, 2018
Peer-review started: February 13, 2018
First decision: February 24, 2018
Revised: March 5, 2018
Accepted: March 7, 2018
Article in press: March 7, 2018
Published online: March 28, 2018
Processing time: 41 Days and 5.6 Hours
Abstract
AIM

To evaluate the usefulness of frozen section diagnosis (FSD) of bile duct margins during surgery for extrahepatic cholangiocarcinoma (CCA).

METHODS

We retrospectively analyzed 74 consecutive patients who underwent surgery for extrahepatic CCA from 2012 to 2017, during which FSD of bile duct margins was performed. They consisted of 40 distant and 34 perihilar CCAs (45 and 55 bile duct margins, respectively). The diagnosis was classified into three categories: negative, borderline (biliary intraepithelial neoplasia-1 and 2, and indefinite for neoplasia), or positive. FSD in the epithelial layer, subepithelial layer, and total layer was compared with corresponding permanent section diagnosis (PSD) postoperatively. Then, association between FSD and local recurrence was analyzed with special reference to borderline.

RESULTS

Analysis of 100 duct margins revealed that concordance rate between FSD and PSD was 68.0% in the total layer, 69.0% in the epithelial layer, and 98.0% in the subepithelial layer. The extent of remaining biliary epithelium was comparable between FSD and PSD, and more than half of the margins lost > 50% of the entire epithelium, suggesting low quality of the samples. In FSD, the rate of negative margins decreased and that of borderline and positive margins increased according to the extent of the remaining epithelium. Diagnostic discordance between FSD and PSD was observed in 31 epithelial layers and two subepithelial layers. Alteration from borderline to negative was the most frequent (20 of the 31 epithelial layers). Patients with positive margin in the total and epithelial layers by FSD demonstrated a significantly worse local recurrence-free survival (RFS) compared with patients with borderline and negative margins, which revealed comparable local RFS. Patients with borderline and negative margins in the epithelial layer by PSD also revealed comparable local RFS. These results suggested that epithelial borderline might be regarded substantially as negative. When classifying the status of the epithelial layer either as negative or positive, concordance rates between FSD and PSD in the total, epithelial, and subepithelial layers were 95.0%, 93.0%, and 98.0%, respectively.

CONCLUSION

During intraoperative assessment of bile duct margin, borderline in the epithelial layer can be substantially regarded as negative, under which condition FSD is comparable to PSD.

Keywords: Cholangiocarcinoma; Bile duct cancer; Frozen section diagnosis; Permanent section diagnosis; Bile duct margin; Biliary intraepithelial neoplasia; Dysplasia; Indefinite for neoplasia; Borderline lesion; Local recurrence

Core tip: Usefulness of intraoperative frozen section diagnosis (FSD) of bile duct margin for extrahepatic cholangiocarcinoma was investigated. The diagnosis was classified into negative, borderline (biliary intraepithelial neoplasia-1 and 2, and indefinite for neoplasia), or positive, and FSD was compared with permanent section diagnosis postoperatively. In contrast to previous studies, positive FSD in the epithelial layer was significantly associated with local recurrence. Furthermore, borderline FSD in the epithelial layer could be substantially regarded as negative, which could aid surgeons to determine the resection range of the bile duct. Finally, we demonstrated that FSD was reliable enough for pathological diagnosis.