Correlation between Frozen Section and Permanent Histopathologic Diagnoses in Adult Orbital Lesions

Introduction: When indicated, intraoperative use of frozen sections may assist in determining the surgical course or appropriate processing of surgical specimens. Knowing the accuracy of a preliminary frozen section diagnosis is important. The purpose of this study is to determine the rate of correlation between frozen and permanent histopathologic diagnoses of adult orbital lesions, analyze characteristics of discordant cases, and examine the effects of discordance on surgical decision-making. Methods: A 15-year retrospective chart review was conducted at a tertiary care center of all adult patients with orbital lesions for which frozen section and corresponding permanent section tissue diagnoses were obtained. Results: Sixty-five orbital surgeries were performed with a total of 89 frozen sections sampled. In 63 surgeries (96.9%), at least 1 frozen section diagnosis matched the final permanent section diagnosis. Overall, frozen section diagnosis corresponded with permanent section diagnosis in 81 of 89 (91.0%) specimens. Of the 8 (9.0%) specimens from 5 unique patients that did not correlate, the final diagnoses on permanent sections were amyloidosis (5), margin-positive infiltrating breast carcinoma (2), and lymphoid hyperplasia (1). The discrepancy between frozen and permanent sections did not alter care in any patient. Conclusion: Frozen section diagnoses correlate with permanent histopathologic tissue diagnosis in adult orbital biopsies in greater than 90% of cases. Among non-correlated specimens, amyloidosis was the most common diagnosis. Although rare, orbital amyloid disorders may be considered in the differential diagnosis of cases of orbital biopsies with nonspecific findings on a frozen section.