NTRK重排的梭形细胞肿瘤（NTRK-RSCN）代表了使用分子手段定义的一组新兴的罕见肿瘤。据我们所知,在英文全文文章中，没有关于这种肿瘤在中国人群中的大量报道。在这里，我们提出了13个具有独特特征的NTRK-RSCN。13名患者中有10名（77％）是没有性别差异的儿童。肿瘤位置包括六个树干，四肢,两个recta，还有一个小肠.组织学形态包括四个脂纤维瘤样神经肿瘤（LPF-NT）样，八个恶性外周神经鞘瘤（MPNST）/纤维肉瘤样，和一种极其罕见的黏液纤维肉瘤样模式。免疫组织化学，所有病例均为CD34、pan-TRK和TRK-A阳性，SOX-10阴性,和H3K27me3完好无损。在13例中的11例（85％）中鉴定出S-100蛋白表达。基因上,通过荧光原位杂交，NTRK1重排被认为是阳性（7/13，54％）或可疑阳性（6/13，46％）。下一代测序和Sanger测序证实了NTRK1与多种伴侣基因的融合，包括五个LMNA，三个TPM3，一个SQSTM1，三个新型CPSF6，IGR（下游PMVK），和GAS2L1基因。有趣的是,最后一个肿瘤同时进行了第二次EWSR1-PBX1融合，从未报道过。4例患者出现局部复发，其中2例发生转移。在我们的研究中,NTRK-RSCN具有特殊的融合，表现出异常或复杂的临床病理特征。组织学线索和IHC有助于简化一小部分潜在候选人。尽管FISH是识别NTRK重排的强大技术，基于RNA/DNA的NGS建议用于高度可疑的病例，其中FISH信号模式无法识别为经典阳性模式。特别是如果考虑靶向治疗。
NTRK-rearranged spindle cell neoplasms (NTRK-RSCNs) represent an emerging group of rare tumours defined using molecular means. To the best of our knowledge, there have been no large series of reports about this tumour in the Chinese population in English full-text articles. Herein, we present 13 NTRK-RSCNs with peculiar characteristics. Ten of the 13 (77%) patients were children without sex differences. The tumour locations included six trunks, four extremities, two recta, and one small bowel. The histological morphology included four lipofibromatosis-like neural tumour (LPF-NT)-like, eight malignant peripheral nerve sheath tumours (MPNST)/fibrosarcoma-like, and one extremely rare myxofibrosarcoma-like pattern. Immunohistochemically, all cases were CD34, pan-TRK and TRK-A positive, SOX-10 negative, and H3K27me3 intact. S-100 protein expression was identified in 11 of 13 (85%) cases. Genetically, NTRK1 rearrangements were considered positive (7/13, 54%) or suspicious for positivity (6/13, 46%) by fluorescence in situ hybridisation. Next-generation sequencing and Sanger sequencing confirmed NTRK1 fusions with a variety of partner genes, including five LMNA, three TPM3, one SQSTM1, three novel CPSF6, IGR (downstream PMVK), and GAS2L1 genes. Interestingly, the last tumour concurrently harboured a second EWSR1-PBX1 fusion, which has never been reported. Four patients developed local recurrence and two of them suffered metastasis. In our study, NTRK-RSCNs had peculiar fusions that displayed unusual or complicated clinicopathological features. Histological clues and IHC helped streamline a small subset of potential candidates. Although FISH is a powerful technology for identifying NTRK rearrangements, RNA-/DNA-based NGS is recommended for highly suspected cases in which FISH signal patterns are not discernible as classic positive patterns, particularly if targeted therapy is considered.
