涉及 TFE3 基因融合的间叶肿瘤多种多样，主要包括以 ASPSCR1::TFE3 融合为特征的肺泡软组织肉瘤 (ASPS)，以及一小部分血管周围上皮样细胞肿瘤 (PEComas)，称为 TFE3 重排 PEComa，大多数经常包含 SFPQ::TFE3 融合。从历史上看，ASPS 和 TFE3 重排的 PEComa 被认为是两个独特的实体，尽管它们已知形态重叠。然而，最近的研究表明它们之间存在潜在的组织遗传学关系，并且已经记录了一些形态学特征更接近 PEComa 而不是 ASPS 但具有 ASPSCR1::TFE3 融合的肿瘤。在本研究中，我们报告了三例具有 ASPSCR1::TFE3 融合的 PEComa 病例。评估了临床病理学特征，并在临床验证的平台上进行了与伴侣无关的靶向下一代测序。患者为两名女性和一名男性，就诊时年龄从 21 岁到 51 岁不等。所有三个肿瘤均位于内脏（直肠、肾脏和子宫颈）。在相对有限的随访期内（范围=9-15个月），所有患者均存活，没有复发或转移性疾病的证据。肿瘤由紧密巢状的上皮样透明细胞结构组成，由精致的血管网络分隔开，其中两个与丰满的梭形细胞片相关，并且没有一个显示出显着的不连贯的肿瘤形态。免疫组织化学显示，除了 TFE3 蛋白外，所有三种肿瘤均显示黑色素 A 和平滑肌肌动蛋白的共表达。 RNA 测序在所有三个病例中均鉴定出 ASPSCR1::TFE3 融合，并通过随后的荧光原位杂交分析得到证实。我们的研究扩展了 TFE3 重排的 PEComa 的分子遗传谱，并进一步表明其与 ASPS 的密切关系。© 2023 John Wiley

Mesenchymal neoplasms involving TFE3 gene fusions are diverse, mainly include alveolar soft part sarcoma (ASPS) that is characterised by ASPSCR1::TFE3 fusion, and a small subset of perivascular epithelioid cell tumours (PEComas) referred to as TFE3-rearranged PEComa, that most frequently harbours SFPQ::TFE3 fusion. Historically, ASPS and TFE3-rearranged PEComa are considered two distinctive entities despite their known morphological overlap. However, recent studies have suggested a potential histogenetic relationship between them, and several neoplasms that showed morphological features more closely fit PEComa rather than ASPS but harboured ASPSCR1::TFE3 fusion have been documented. In this study, we report three cases of PEComa with ASPSCR1::TFE3 fusion.Clinicopathological features were assessed and partner agnostic targeted next-generation sequencing on clinically validated platforms were performed. The patients are two females and one male with age at presentation ranging from 21 to 51 years. All three tumours were located in the viscera (rectum, kidney and cervix). On a relatively limited follow-up period (range = 9-15 months), all patients are alive without evidence of recurrent or metastatic disease. The neoplasms were composed of tight nested architecture of epithelioid clear cells separated by a delicate vascular network, two of which were associated with sheets of plump spindle cells, and none showed significant discohesive tumour morphology. Immunohistochemically, in addition to TFE3 protein, all three neoplasms demonstrated co-expression of melan-A and smooth muscle actin. RNA-sequencing identified ASPSCR1::TFE3 fusion in all three cases that were confirmed by subsequent fluorescence in-situ hybridisation analyses.Our study expands the molecular genetic spectrum of TFE3-rearranged PEComa and further indicates its close relationship to ASPS.© 2023 John Wiley & Sons Ltd.