E265: Intraoperative Frozen Pathology is Highly Concordant with Permanent Histopathology

ePoster Abstract Author(s)

Michael J. Kirsch, II, MD, MS

Resident Physician
University of Colorado Anschutz Medical Campus
Denver, Colorado, United States

Submitter(s)

Michael J. Kirsch, II, MD, MS

Resident Physician
University of Colorado Anschutz Medical Campus
Denver, Colorado, United States

Author(s)

Michael J. Kirsch, II, MD, MS

Resident Physician
University of Colorado Anschutz Medical Campus
Denver, Colorado, United States
JE

Jacob Edwards, BS

Medical Student
University of Colorado School of Medicine, United States
Elliott J. Yee, MD (he/him/his)

General Surgery Resident
University of Colorado - Anschutz, CO
Denver, Colorado, United States
Salvador Rodriguez Franco, MD (he/him/his)

Senior Research Associate
University of Colorado Anschutz Medical Campus
Aurora, Colorado, United States
Oskar Franklin, MD, PhD

Visiting Research Fellow
University of Colorado Anschutz Medical Campus, Department of Sugery, Division of Surgical Oncology
Englewood, Colorado, United States
Toshitaka Sugawara, MD, PhD

Research Fellow
University of Colorado Anschutz Medical Center, Department of Surgery, Division of Surgical Oncology
Denver, Colorado, United States
TS

Thomas Stoop, MD

Research Fellow
University of Colorado Anschutz Medical Center, Department of Surgery, Division of Surgical Oncology, United States
CM

Cheryl L. Meguid, NP

Director, Pancreatic Cancer High Risk Screening Clinic
University of Colorado Cancer Center, United States
Steven Ahrendt, MD

Professor
University of Colroado
Aurora, Colorado, United States
RS

Richard D. Schulick, MD, MBA

Chair of Surgery and Cancer Center Director
University of Colorado, Department of Surgery, United States
MD

Marco Del Chiaro, MD, PhD

Division Chief Surgical Oncology
University of Colorado Anschutz Medical Campus, United States

Introduction: Intraductal Papillary Mucinous Neoplasms of the pancreas (IPMNs) are pre-malignant precursors of pancreatic cancer. Intraoperative frozen section pathology (IFS) is used to evaluate surgical margins in real time. However, the concordance between IFS and permanent pathological diagnosis for IPMN is understudied. We evaluated the diagnostic accuracy of IFS in IPMN resection.

Methods: We performed a high-volume single-center retrospective analysis of prospectively collected clinical data of patients undergoing pancreatic resection for presumed IPMN without suspected pancreatic adenocarcinoma between 2013 and September 2023. The outcomes of interest were IFS and permanent histopathological diagnoses from transection margin specimens obtained during surgical resection. IFS margins with normal pancreas parenchyma, low-grade dysplasia (LGD), or the absence of high-grade dysplasia and invasive IPMN were classified as negative.

Results:

There were 181 patients who met the inclusion criteria. The preoperative diagnosis was main duct in 53 (29.3%), mixed type in 63 (34.8%), and side branch IPMN in 65 (35.9%) patients. 93.4% (n=169) of patients had IFS on a resection margin. Of these, 144 patients (85.2%) had margins negative for HGD or invasive IPMN on IFS, 6 patients (3.3%) had HGD, and 5 (2.8%) had invasive IPMN. Of the 11 patients who had HGD or invasive disease on initial IFS, 9 (81.8%) underwent extended resection of the pancreas during index resection, including 4 (2.4%) who underwent a total pancreatectomy. On permanent histopathology, 68.5% (n=124) had non-invasive IPMN and 23.2% (n=42) had adenocarcinoma, 35 (87.5%) of which had originated from IPMN. 6 patients (3.6%) had HGD involvement of their permanent pathological margins. There was only 1 patient (0.6%) who had IFS diagnosis that underdiagnosed HGD when compared to final pathology, which was revised upon review, as noted above. No patient had IFS that underdiagnosed invasive IPMN.

Conclusions:

In this study comparing IFS with definite histopathological diagnosis, only 1 patient (0.6%) had IFS diagnosis that underdiagnosed the permanent margins. IFS is highly accurate for differentiating normal tissue and LGD from HGD and invasive IPMN when compared with the definite histopathological diagnosis. Further evaluation is needed to assess correlation between IFS diagnosis and recurrence of invasive IPMN.

Learning Objectives:

Upon completion, participants will be able to describe the concordance between intraoperative frozen section pathology and permanent histopathological diagnosis.
Upon completion, participants will be able to describe the indications for extending the resection margin in pancreatectomy for IPMN.
Upon completion, participants will be able to discuss the dysplasia grading system for IPMN.