Department of Pathology and Laboratory Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, USA.
Department of Pathology, Moffitt Cancer Center, Tampa, FL, USA.
Histopathology. 2021 Jan;78(2):300-309. doi: 10.1111/his.14229. Epub 2020 Oct 22.
Signet ring cell carcinoma (SRCC) is challenging to recognise on intra-operative frozen sections, with known high false-negative rates. The objective of this study was to investigate common factors contributing to discrepancies between intra-operative frozen diagnoses and those made upon review of permanent sections, and summarise our experiences gained and lessons learned on minimising errors on intra-operative frozen diagnoses of gastrointestinal SRCC.
We retrospectively examined our pathology database from 25 May 2000 to 1 January 2018 and re-reviewed intra-operative frozen sections and permanent haematoxylin and eosin (H&E) slides for specimens confirmed with SRCC on permanent sections. This study includes 83 specimens taken from 50 patients, with an accuracy of 85.5%. Main common factors causing discordance or deferral in recognising SRCC between intra-operative frozen procedures and permanent sections include: (i) resemblance of clusters of SRCC cells with a myxoid background; (ii) disguise as normal or reactive cells (histiocytes, macrophages, large reactive lymphocytes, plasma cells or adipocytes) due to their relatively clear or depleted cytoplasmic mucin; and (iii) histological sampling errors, leading to misses of small foci of SRCC on frozen section slides.
An accurate diagnosis of SRCC during intra-operative frozen consultations remains challenging. Based on our experiences and lessons, the most important strategies to reduce diagnostic errors are: (i) understanding the unusual histomorphological features of SRCC cells on frozen sections including, but not limited to, intracellular mucin depletion, absence of desmoplasia and no adjacent pre-cancer changes; and (ii) close attention to abrupt transition from normal architecture (e.g. glandular or submucosal loose connective tissue) to myxoid and/or inflammatory-like appearance, which potentially harbours SRCC.
印戒细胞癌 (SRCC) 在术中冷冻切片中难以识别，其假阴性率已知较高。本研究旨在探讨导致术中冷冻诊断与石蜡切片复查诊断结果不一致的常见因素，并总结我们在减少胃肠道 SRCC 术中冷冻诊断错误方面的经验教训。
我们回顾性地检查了我们的病理数据库，时间范围为 2000 年 5 月 25 日至 2018 年 1 月 1 日，并重新审查了术中冷冻切片和石蜡切片的苏木精和伊红（H&E）切片，这些切片在石蜡切片上证实为 SRCC。本研究包括 50 名患者的 83 个标本，准确率为 85.5%。导致术中冷冻和石蜡切片之间 SRCC 识别不一致或延迟的主要常见因素包括：(i) 具有黏液背景的 SRCC 细胞簇的相似性；(ii) 由于相对清晰或耗尽的细胞质黏液，SRCC 细胞伪装为正常或反应性细胞（组织细胞、巨噬细胞、大反应性淋巴细胞、浆细胞或脂肪细胞）；(iii) 组织学采样误差，导致在冷冻切片上错过 SRCC 的小病灶。
术中冷冻咨询时准确诊断 SRCC 仍然具有挑战性。基于我们的经验和教训，减少诊断错误的最重要策略是：(i) 了解 SRCC 细胞在冷冻切片上的不寻常组织形态学特征，包括但不限于细胞内黏液耗竭、无纤维增生和无相邻癌前变化；(ii) 密切注意从正常结构（如腺性或黏膜下疏松结缔组织）向黏液样和/或炎症样外观的突然转变，这可能潜藏着 SRCC。
