卵巢性索间质肿瘤（SCST）由于形态多样，在冰冻切片（FS）咨询期间存在诊断困难。本研究旨在评估我机构SCST FS评估的准确性，并探讨导致FS诊断不正确的原因。还强调了模仿 SCST 并在 FS 期间诊断为此类的病例。我们分析了 121 例卵巢 SCST 病例及其模拟病例，这些病例在 10 年的时间内接受了 FS 咨询，以评估 FS 的准确性、推迟的原因和差异。与最终诊断相比，FS 诊断一致、延迟和不一致的病例分别为 50 例（41.3%）、39 例（32.2%）和 32 例（26.5%）。主要差异（9/121，7.4%）主要与成人颗粒细胞瘤（AGCT）的诊断有关。纤维瘤性 AGCT 在 FS 上被误解为纤维瘤，而囊性 AGCT 被称为良性囊肿。相反，中肾样腺癌、梭状子宫内膜样癌和卵泡膜瘤在 FS 上被误解为 AGCT。另一个不一致的病例是具有明显纤维瘤基质的克鲁肯伯格肿瘤，其中恶性印戒细胞被忽视并被误解为纤维瘤。较小的差异主要与纤维瘤相关（21/23，91.3%），其中由于采样问题和误解为平滑肌瘤，遗漏了较小但可能有影响的细节，例如细胞纤维瘤和有丝分裂活跃的细胞纤维瘤。卵巢 SCST 的 FS 评估显示良性、不确定/低恶性潜力和恶性类别的总体准确度分别为 78.5%、81.0% 和 81.8%。在所有具有可用随访信息的病例中（120/121 例），均未出现与 FS 相关的不良临床影响。卵巢 SCST 的术中 FS 评估具有挑战性。少数案例被误解，其中 AGCT 是发生错误的主要群体。了解常见的诊断陷阱和困难，并应用逐步方法，包括（1）获取全面的临床信息，（2）彻底的宏观检查和定向取样，（3）仔细的显微镜检查，考虑陷阱和模仿，（4）在疑难病例中与外科医生进行有效沟通，以及 (5) 在具有挑战性的病例中与专科同事进行协商，将提高病理学家未来报告的准确性和对此类病例的管理。版权所有 © 2024 澳大利亚皇家病理学家学院。由 Elsevier B.V. 出版。保留所有权利。

Ovarian sex cord-stromal tumours (SCSTs) present diagnostic difficulties during frozen section (FS) consultations due to their diverse morphology. This study aimed to evaluate the accuracy of FS evaluation of SCSTs in our institution, as well as to examine the reasons leading to incorrect FS diagnosis. Cases mimicking SCSTs and diagnosed as such during FS were also highlighted. We analysed 121 ovarian SCST cases and their mimics which underwent FS consultations over a 10-year period, to evaluate FS accuracy, reasons for deferrals and discrepancies. FS diagnoses were concordant, deferred and discrepant compared to the final diagnosis in 50 (41.3%), 39 (32.2%) and 32 (26.5%) cases, respectively. Major discrepancies (9/121, 7.4%) were mostly related to the diagnosis of adult granulosa cell tumour (AGCT). A fibromatous AGCT was misinterpreted as fibroma on FS, while a cystic AGCT was called a benign cyst. Conversely, a mesonephric-like adenocarcinoma, a sertoliform endometrioid carcinoma and a thecoma were misinterpreted as AGCT on FS. Another discrepant case was a Krukenberg tumour with prominent fibromatous stroma in which malignant signet ring cells were overlooked and misinterpreted as fibroma. Minor discrepancies were primarily associated with fibroma (21/23, 91.3%), wherein minor but potentially impactful details such as cellular fibroma and mitotically active cellular fibroma were missed due to sampling issues and misinterpretation as leiomyoma. FS evaluation for ovarian SCSTs demonstrated an overall accuracy of 78.5%, 81.0% and 81.8% for benign, uncertain/low malignant potential and malignant categories, respectively. There was no FS-related adverse clinical impact in all cases with available follow-up information (120/121 cases). Intraoperative FS evaluation of ovarian SCSTs is challenging. A small number of cases were misinterpreted, with AGCTs being the primary group where errors occur. Awareness of common diagnostic pitfalls and difficulties, alongside application of a stepwise approach, including (1) obtaining comprehensive clinical information, (2) thorough macroscopic examination and directed sampling, (3) meticulous microscopic examination with consideration of pitfalls and mimics, (4) effective communication with surgeons in difficult cases, and (5) consultation of subspecialty colleagues in challenging cases, will enhance pathologists' reporting accuracy and management of such cases in the future.Copyright © 2024 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.