Department of Radiology, Lucile Packard Children's Hospital, Stanford University, Stanford, CA.
Department of Biostatistics, College of Public Health & Health Professions and College of Medicine, University of Florida, Gainesville, FL.
AJR Am J Roentgenol. 2020 May;214(5):987-994. doi: 10.2214/AJR.19.22301. Epub 2020 Mar 11.
Distinguishing nephrogenic rests from small Wilms tumors can be challenging. This retrospective study was performed to determine if imaging characteristics can be used to distinguish nephrogenic rests from Wilms tumors. All cases of pathologically confirmed nephrogenic rests and Wilms tumors smaller than 5 cm in maximum dimension on imaging in patients younger than 5 years old were identified from the Children's Oncology Group AREN03B2 study (July 2006-August 2016). Exclusion criteria were chemotherapy before pathologic evaluation or more than 30 days between imaging and surgery; in addition, patients with nephrogenic rests occurring within or juxtaposed to a Wilms tumor and patients with diffuse hyperplastic perilobar nephroblastomatosis were excluded. Two radiologists who were blinded to pathology results assessed all lesions. The two-sample test was used for continuous variables, and the Fisher exact test was used for categoric variables. ROC analysis was performed to determine the optimal size cutoff for distinguishing between nephrogenic rests and Wilms tumors. Thirty-one pathologically confirmed rests (20 perilobar, 11 intralobar) and 26 Wilms tumors smaller than 5 cm met the eligibility criteria for study inclusion. The median diameter of the nephrogenic rests was 1.3 cm (range, 0.7-3.4 cm) and the median diameter of the Wilms tumor was 3.2 cm (range, 1.8-4.9 cm) ( < 0.001). Imaging findings supportive of Wilms tumors were spherical ( < 0.001) and exophytic ( < 0.001) lesions. Perilobar rests (17/20) were more likely to be homogeneous than intralobar rests (3/11) or Wilms tumor (3/26) ( < 0.001). ROC analysis showed that the optimal size cutoff for distinguishing between nephrogenic rests and Wilms tumors was 1.75 cm. In children younger than 5 years old, the diagnosis of a Wilms tumor should be favored over a nephrogenic rest when a renal mass is spherical, exophytic, or larger than 1.75 cm. Homogeneity favors the diagnosis of perilobar nephrogenic rests, whereas intralobar rests and Wilms tumors are more likely to be inhomogeneous.
鉴别肾源性遗迹与小的威尔姆斯瘤可能具有挑战性。本回顾性研究旨在确定影像学特征是否可用于区分肾源性遗迹与威尔姆斯瘤。从儿童肿瘤学组 AREN03B2 研究（2006 年 7 月至 2016 年 8 月）中确定了所有经病理证实的小于 5cm 的肾源性遗迹和威尔姆斯瘤病例，这些病例在影像学上均小于 5 岁的患者。排除标准为化疗前进行病理评估或影像学与手术之间间隔超过 30 天；此外，排除了发生在威尔姆斯瘤内或紧邻威尔姆斯瘤的肾源性遗迹以及弥漫性增生性副肾胚细胞瘤病的患者。两名对病理结果不知情的放射科医生评估了所有病变。对于连续变量使用两样本检验，对于分类变量使用 Fisher 确切检验。进行 ROC 分析以确定区分肾源性遗迹与威尔姆斯瘤的最佳大小截止值。31 例经病理证实的遗迹（20 例副肾胚细胞瘤，11 例肾内）和 26 例小于 5cm 的威尔姆斯瘤符合研究纳入标准。肾源性遗迹的中位直径为 1.3cm（范围 0.7-3.4cm），威尔姆斯瘤的中位直径为 3.2cm（范围 1.8-4.9cm）（<0.001）。支持威尔姆斯瘤的影像学发现为球形（<0.001）和外生性病变（<0.001）。副肾胚细胞瘤（17/20）比肾内遗迹（3/11）或威尔姆斯瘤（3/26）更可能为均质（<0.001）。ROC 分析表明，区分肾源性遗迹与威尔姆斯瘤的最佳大小截止值为 1.75cm。在 5 岁以下的儿童中，当肾肿块为球形、外生性或大于 1.75cm 时，应更倾向于诊断为威尔姆斯瘤而非肾源性遗迹。均质性支持副肾胚细胞瘤的诊断，而肾内遗迹和威尔姆斯瘤更可能为不均质。
