Tekavec Kristina, Švara Tanja, Knific Tanja, Mlakar Jernej, Gombač Mitja, Cantile Carlo
Department of Veterinary Science, University of Pisa, Pisa, Italy.
Veterinary Faculty, Institute of Pathology, Wild Animals, Fish and Bees, University of Ljubljana, Ljubljana, Slovenia.
Front Vet Sci. 2022 Jul 29;9:921720. doi: 10.3389/fvets.2022.921720. eCollection 2022.
Nerve sheath tumors (NSTs) are characterized by neoplastic proliferation of Schwann cells, perineurial cells, endoneurial and/or epineurial fibroblasts. Diagnosis of NST is often challenging, particularly in distinguishing malignant NST (MNST) from other soft tissue sarcomas, or sometimes between low-grade MNST and benign NST. Recent studies in human pathology have demonstrated loss of trimethylation at lysine 27 of histone 3 (H3K27me3) in a subset of MNSTs using immunohistochemistry. Loss of H3K27me3 expression is rare in other high-grade sarcomas and also appears to be useful in distinguishing benign and low-grade MNSTs from high-grade subsets. In our retrospective study, we performed H3K27me3 immunohistochemistry in 68 canine tumors previously diagnosed as NST. We detected loss of H3K27me3 expression in 25% ( = 17) of all canine NST, including one neurofibroma, whereas 49% ( = 33) of tumors had mosaic loss of expression and 26% ( = 18) retained expression. No statistically significant differences were found between H3K27me3 expression, histopathological features of tumors, and their immunoreactivity for Sox10, claudin-1, GFAP, and Ki67. Because the classification of canine NST is not yet fully established and its correlation with the prognosis and clinical course of the disease is lacking, prospective studies with possible genetic analyses are needed to assess the true diagnostic value of H3K27me3 loss in canine NST.
神经鞘瘤（NSTs）的特征是施万细胞、神经束膜细胞、神经内膜和/或神经外膜成纤维细胞的肿瘤性增殖。NST的诊断往往具有挑战性，尤其是在区分恶性NST（MNST）与其他软组织肉瘤时，或者有时在区分低级别MNST和良性NST之间。人类病理学的最新研究表明，使用免疫组织化学方法，在一部分MNST中发现组蛋白3赖氨酸27位点（H3K27me3）的三甲基化缺失。H3K27me3表达缺失在其他高级别肉瘤中很少见，并且似乎也有助于区分良性和低级别MNST与高级别亚型。在我们的回顾性研究中，我们对68例先前诊断为NST的犬类肿瘤进行了H3K27me3免疫组织化学检测。我们在所有犬类NST的25%（=17）中检测到H3K27me3表达缺失，其中包括1例神经纤维瘤，而49%（=33）的肿瘤存在表达的镶嵌性缺失，26%（=18）保留表达。在H3K27me3表达、肿瘤的组织病理学特征及其对Sox10、claudin-1、GFAP和Ki67的免疫反应性之间未发现统计学上的显著差异。由于犬类NST的分类尚未完全确立，并且缺乏其与疾病预后和临床病程的相关性，因此需要进行可能的基因分析的前瞻性研究，以评估H3K27me3缺失在犬类NST中的真正诊断价值。
