Abstract：
OBJECTIVE: 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.
RESULTS: 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.
CONCLUSIONS: Our study expands the molecular genetic spectrum of TFE3-rearranged PEComa and further indicates its close relationship to ASPS.
RESULTS: 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.
CONCLUSIONS: Our study expands the molecular genetic spectrum of TFE3-rearranged PEComa and further indicates its close relationship to ASPS.
摘要：
目的：涉及TFE3基因融合的间充质肿瘤是多样的，主要包括肺泡软组织肉瘤（ASPS），其特征是ASPSCR1::TFE3融合，和一小部分血管周围上皮样细胞肿瘤（PEComas），称为TFE3重排PEComa，最常见的是SFPQ::TFE3融合。历史上,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，和一些显示形态特征更接近PEComa而不是ASPS，但具有ASPSCR1::TFE3融合的肿瘤已被记录。在这项研究中,我们报告3例PEComa伴ASPSCR1::TFE3融合。
结果：评估了临床病理特征，并在临床验证的平台上进行了伴侣不可知的靶向下一代测序。患者为两名女性和一名男性，其年龄在21至51岁之间。所有三个肿瘤都位于内脏（直肠，肾脏和子宫颈）。在相对有限的随访期（范围=9-15个月），所有患者均存活,无复发或转移性疾病的证据.肿瘤由紧密的嵌套结构的上皮样透明细胞组成，由精细的血管网隔开。其中两个与丰满的梭形细胞有关，没有显示明显的盘状肿瘤形态。免疫组织化学，除了TFE3蛋白，所有三种肿瘤均表现出melan-A和平滑肌肌动蛋白的共表达。RNA测序在所有三种情况下鉴定了ASPSCR1::TFE3融合,其通过随后的荧光原位杂交分析得到证实。
结论：我们的研究扩展了TFE3重排PEComa的分子遗传谱，并进一步表明其与ASPS的密切关系。
结果：评估了临床病理特征，并在临床验证的平台上进行了伴侣不可知的靶向下一代测序。患者为两名女性和一名男性，其年龄在21至51岁之间。所有三个肿瘤都位于内脏（直肠，肾脏和子宫颈）。在相对有限的随访期（范围=9-15个月），所有患者均存活,无复发或转移性疾病的证据.肿瘤由紧密的嵌套结构的上皮样透明细胞组成，由精细的血管网隔开。其中两个与丰满的梭形细胞有关，没有显示明显的盘状肿瘤形态。免疫组织化学，除了TFE3蛋白，所有三种肿瘤均表现出melan-A和平滑肌肌动蛋白的共表达。RNA测序在所有三种情况下鉴定了ASPSCR1::TFE3融合,其通过随后的荧光原位杂交分析得到证实。
结论：我们的研究扩展了TFE3重排PEComa的分子遗传谱，并进一步表明其与ASPS的密切关系。
