Department of Nuclear Medicine, Changhai Hospital, No. 168, Changhai Rd, Yangpu District, Shanghai, 200433, China.
AJR Am J Roentgenol. 2020 Sep;215(3):645-651. doi: 10.2214/AJR.19.22467. Epub 2020 Jul 1.
The purpose of this article is to investigate the value of F-FDG PET/CT and enhanced CT in the diagnosis of renal cell carcinoma (RCC) with sarcomatoid differentiation and the differential diagnosis of clear cell renal cell carcinoma (ccRCC). Among patients with renal tumors confirmed by pathologic examination from September 2010 to August 2019, 29 patients with RCC with sarcomatoid differentiation and 82 patients with ccRCC who underwent FDG PET/CT, renal contrast-enhanced CT examination, or both, before surgery were studied. Features of the two groups on CT and PET/CT were retrospectively reviewed. The tumor size of RCC with sarcomatoid differentiation was larger than that of ccRCC ( = 0.0086). Cystic necrosis, peritumoral neovascularity, and metastasis were more common in RCC with sarcomatoid differentiation ( = 0.0052, = 0.0008, < 0.0001, respectively). The ratio of necrotic area to tumor diameter of RCC with sarcomatoid differentiation was statistically significantly larger than that of ccRCC ( = 0.0032). Three cases of RCC with sarcomatoid differentiation showed a large central necrotic area and dense intratu-moral neovascularity in the surrounding parenchyma, defined as the ring-of-fire sign, which was not found in ccRCC. The maximum standardized uptake value (SUV), mean standardized uptake value (SUV), and peak standardized uptake value (SUV) of RCC with sarcomatoid differentiation were statistically significantly higher than those for ccRCC (all < 0.0001), and the SUV, SUV, and SUV cutoff values of 5.4, 4.2, and 5.0, respectively, were helpful for discrimination. Imaging features including higher SUV, SUV, and SUV; a larger ratio of necrotic area to tumor diameter; the presence of peritumoral neovascularity; and metastasis are more commonly associated with RCC with sarcomatoid differentiation than with ccRCC. The ring-of-fire sign and SUV, SUV, SUV cutoff values of 5.4, 4.2, 5.0, respectively, may be helpful to indicate RCC with sarcomatoid differentiation.
本文旨在探讨 F-FDG PET/CT 和增强 CT 在诊断具有肉瘤样分化的肾细胞癌（RCC）和鉴别透明细胞肾细胞癌（ccRCC）中的价值。在 2010 年 9 月至 2019 年 8 月期间，经病理检查证实为肾肿瘤的患者中，研究了 29 例具有肉瘤样分化的 RCC 患者和 82 例术前接受 FDG PET/CT、肾增强 CT 检查或两者检查的 ccRCC 患者。回顾性分析了两组 CT 和 PET/CT 的特征。RCC 具有肉瘤样分化的肿瘤大小大于 ccRCC（=0.0086）。囊性坏死、肿瘤周围新生血管和转移在具有肉瘤样分化的 RCC 中更为常见（=0.0052，=0.0008，<0.0001）。RCC 具有肉瘤样分化的肿瘤坏死区与肿瘤直径之比大于 ccRCC（=0.0032）。有 3 例具有肉瘤样分化的 RCC 表现为中央大坏死区和周围实质内密集的瘤内新生血管，定义为“火环征”，在 ccRCC 中未发现。RCC 具有肉瘤样分化的最大标准化摄取值（SUV）、平均标准化摄取值（SUV）和峰值标准化摄取值（SUV）均显著高于 ccRCC（均<0.0001），SUV、SUV 和 SUV 截断值分别为 5.4、4.2 和 5.0，有助于鉴别。SUV、SUV 和 SUV 较高；坏死区与肿瘤直径的比值较大；存在肿瘤周围新生血管；以及转移等影像学特征与具有肉瘤样分化的 RCC 更为常见，与 ccRCC 相比。火环征和 SUV、SUV、SUV 截断值分别为 5.4、4.2、5.0，可能有助于提示具有肉瘤样分化的 RCC。
