FDG PET/CT and MR imaging of CD34-negative soft-tissue solitary fibrous tumor with NAB2-STAT6 fusion gene.
FDG PET/CT and MR imaging of CD34-negative soft-tissue solitary fibrous tumor with NAB2-STAT6 fusion gene.
复制标题
具有 NAB2-STAT6 融合基因的 CD34 阴性软组织孤立性纤维瘤的 FDG PET/CT 和 MR 成像。
作者：
J. Nishio;H. Iwasaki;M. Aoki;K. Nabeshima;M. Naito
摘要胸膜外孤立性纤维性肿瘤是一种罕见的间叶性肿瘤，具有中等的生物学潜能。在此，我们描述了放射学，组织学，免疫组织化学和分子遗传学特征的SFT发生在左大腿的一个55岁的女人。磁共振成像显示一个边界清楚的肿块，T1加权序列呈中等信号强度，T2加权序列呈不均匀高信号强度。增强T1加权序列显示肿块均匀强化。可见突出的血管蒂。正电子发射断层扫描（PET）/计算机断层扫描（CT）显示肿块中中度18 F-氟脱氧葡萄糖（FDG）摄取（最大标准化摄取值，4.45）。在开放性活检后，进行了肿瘤的广泛切除。组织学上，肿瘤是由梭形细胞增生的纤维间质与局灶性玻璃样变。薄壁分支状血管外皮细胞瘤样血管。免疫组化显示肿瘤细胞信号转导和转录激活因子6（STAT 6）呈弥漫性阳性，但CD 34呈阴性。MIB-1标记指数小于5%。随后的逆转录-聚合酶链反应分析鉴定了神经生长因子诱导A结合蛋白2-STAT 6基因融合体。我们的病例支持STAT 6免疫组化作为辅助诊断CD 34阳性丢失的软组织SFT的效用。据我们所知，这是第一个报告显示的FDG PET/CT表现的软组织SFT。
Extrapleural solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm of intermediate biological potential. Herein, we describe the radiological, histological, immunohistochemical and molecular genetic features of an SFT arising in the left thigh of a 55-year-old woman. Magnetic resonance imaging exhibited a well-defined mass with intermediate signal intensity on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. Contrast-enhanced T1-weighted sequences showed strong homogeneous enhancement of the mass. A prominent vascular pedicle was visible. Integrated positron-emission tomography (PET)/computed tomographic (CT) scan demonstrated a moderate 18F-fluorodeoxyglucose (FDG) uptake (maximum standardized uptake value, 4.45) in the mass. Following an open biopsy, wide excision of the tumor was performed. Histologically, the tumor was composed of a proliferation of spindle cells in a fibrous stroma with focal hyalinization. Thin-walled branching hemangiopericytoma-like vessels were observed. Immunohistochemically, the tumor cells were diffusely positive for signal transducer and activator of transcription 6 (STAT6) but negative for CD34. The MIB-1 labeling index was less than 5%. Subsequent reverse transcriptase-polymerase chain reaction analysis identified a nerve growth factor inducible-A binding protein 2-STAT6 gene fusion. Our case supports the utility of STAT6 immunohistochemistry as an adjunct in the diagnosis of soft-tissue SFT with loss of CD34 positivity. To the best of our knowledge, this is the first report showing the FDG PET/CT findings of soft-tissue SFT.