肾少见良性肿瘤的影像学诊断分析

目的:分析肾少见良性肿瘤的影像学表现,提高术前诊断准确性。方法:回顾性分析20例肾脏少见良性肿瘤的影像学资料,其中嗜酸细胞腺瘤9例、后肾腺瘤1例、不典型血管平滑肌脂肪瘤(AML)4例(上皮样型2例,平滑肌瘤型2例)、纤维瘤3例、中胚叶肾瘤2例、神经鞘瘤1例。15例行CT检查,3例行MRI检查,2例同时进行了CT和MRI检查。结果:本组病例除1例中胚叶肾瘤和1例神经鞘瘤外,均表现为境界清楚、均质性的实性肿块影。中央瘢痕及可以高于肾皮质的强化方式是嗜酸细胞腺瘤的特征。不典型AML、纤维瘤、后肾腺瘤及实性中胚叶肾瘤,在抑脂序列T2WI上呈较明显的低信号,且纤维瘤和后肾腺瘤都具有延迟强化的特征。良性神经鞘瘤具有境界清楚和易于发生坏死、囊变的特征。囊性中胚叶肾瘤缺少特征性的影像学表现。结论:肾少见良性肿瘤的影像学表现具有一定的特征性,有助于与肾癌进行鉴别,准确的术前诊断对指导治疗具有重要价值。

Imaging Diagnosis of Rare Benign Renal Tumors

Objective:To investigate the imaging features of rare benign renal tumors and to review the literature,in order to improve the accuracy of diagnosis.Methods:Imaging materials of 20 patients with rare benign renal tumors were analyzed retrospectively,including oncocytomas (n=9),atyical angiomyolipoma (AML,n=4;epitheliod type and leiomyoma type for 2 each),fibroma (n=3),mesoblastic nephroma (n=2),metanephric adenoma and neurilemmoma for 1 patient each.Fifteen patients underwent CT examination,4 patients underwent MR examination,2 patients had both CT and MRI.Results:Apart from the patients with mesoblastic nephroma or neurilemmoma,all the other tumors showed well-defined,homogeneous,solid mass.Central scar as well as enhancement of the mass higher than that of renal cortex were the characteristic findings of oncocytoma.Atypical AML,fibroma,metanephric adenoma and solid mesoblastic nephroma showed obvious hypo-intensity on fat suppression T2WI.Delayed enhancement after contrast administration might be revealed in fibroma and metanephric adenoma.Characteristic imaging features of benign neurilemmoma were well-defined,apt to have necrosis and cystic formation.No characteristic imaging finding was assessed in cystic mesoblastic nephroma.Conclusion:Charac-teristic imaging findings could be assessed in rare benign renal tumors,which is helpful in the differential diagnosis from renal cell carcinoma.Accurate preoperative diagnosis has important value in therapy guidance.