累及肾被膜下的血管平滑肌脂肪瘤CT表现

CT Findings of Renal Angiomyolipoma Extended to Subcapsular Area

目的:探讨累及肾被膜下的血管平滑肌脂肪瘤CT特征。方法:回顾性分析29例患者33个累及肾被膜下的血管平滑肌脂肪瘤的CT表现,其中10例有尿路排泄性造影检查,5例行MRI检查,2例行DSA检查。15例经手术病理证实。结果:33个肿块的中心均位于肾实质外,肿块最大径范围2.5～12cm,平均(5.4±2.2)cm。富脂肪肿块30个(90.9%),21个(70%)肿块内脂肪和软组织混杂分布,16个肿块增强扫描软组织呈持续网格状强化,9个(30%)病灶内软组织为结节状,4个病灶均呈持续强化,另1个结节为慢性血肿,其内见动脉瘤;3个(9.1%)病灶呈乏脂肪性肿块,1个早期强化另2个呈持续强化。5个肿块因自发破裂合并出血。结论:累及肾被膜下血管平滑肌脂肪瘤较大,多富含脂肪,CT易于定位和定性诊断,并判断有无破裂出血。

Objective：To explore the CT findings of renal angiomyolipoma extended to subcapsular area. Methods：CT features of 33 subcapsular masses of renal angiomyolipoma in 29 patients were retrospectively analyzed. Of them, 10 patients had undergone intravenous urography examination （IVU）,5 had MRI and 2 had DSA. 15 cases had been proved by surgery and pathology. Results：Center of all 33 tumors located out of the renal parenchyma and the mean size was （5.4 ± 2.2）cm （range 2.5-12cm）. There was more fat in 30 （90.9%） tumors,it located among the soft tissue in 21 （70%） of them. Soft tissue structures showed reticulate enhancement in all 16 tumors during dynamic contrast scanning ; the soft tissue displayed local nodule in the tumor in other 9 （30%） tumors, and 4 of them showed prolonged enhancement pattern, and one was chronic hematoma with an aneurysm in it. There was minimal fat in the remaining 3 （9.1%） tumors, and one with an early washout pattern,two with prolonged enhancement pattern. There was hemorrhage associated with spontaneous rupture of the tumor in 5 patients. Conclusion：Renal angiomyolipomas extending to subcapsular area are mostly large and contain more fat. It is easy to make diagnosis and to find hemorrhage on CT.