肾脏上皮样血管平滑肌脂肪瘤的MSCT表现(附6例报告)

MSCT imaging appearance of renal epithelioid angiomyolipomas: report of six cases

目的探讨肾脏上皮样血管平滑肌脂肪瘤（epithelioid angiomyolipoma,EAML）的MSCT表现,提高对本病的认识和诊断水平。方法回顾性分析6例经手术病理证实为肾脏EAML的MSCT表现,所有病例术前均进行了双肾MSCT平扫及动态增强扫描。结果 6例患者中5例为单发病灶,1例为多发病灶,但仅最大病灶进行手术切除经病理证实。所有病例均累及单侧肾脏。病灶最大径范围10-72mm,平均值为30.8mm。病灶边缘均无分叶,边界清晰,均向肾外突出生长导致肾轮廓改变,其中5个病灶与肾实质界面成角,外观酷似＂冰淇淋＂。所有病灶CT平扫及增强密度均不均匀,无钙化,5个病灶呈＂快进慢出＂的强化方式,仅1例病灶呈＂快进快出＂的强化方式。增强扫描4个大病灶（最大径≥39mm）内可见明显强化的粗大的瘤内血管,2个小病灶（最大径≤20mm）内未见瘤内血管。5个病灶内存在CT可分辨的脂肪密度,所有病例均无局部浸润、血管受累和远处转移。结论肾脏EAML与经典型AML和肾癌的CT表现存在重叠,鉴别诊断困难。EAML内部可含有或不含有CT可分辨的脂肪组织,含有CT可分辨脂肪组织的EAML与经典型AML难以鉴别。不含有CT可分辨脂肪组织的EAML与肾癌难以鉴别。EAML的最终诊断仍依靠病理学检查。

Objective To evaluate multislice spiral computed tomography（ MSCT） imaging manifestations of renal epithelioid angiomyolipomas（ EAMLs） for better understanding and improving the diagnosis of the tumour. Methods MSCT images from 6cases with histologically confirmed EAMLs identified by surgical excision were retrospectively analysed. All patients underwent MSCT with and without contrast medium administration. Results There were multiple lesions in one case and single lesion in another five cases. Unilateral kidney was involved in all cases. The largest diameter of the six EAMLs ranged from 10 to 72 mm（ mean,30. 8 mm）. Bulging contour of the involved kidney,distinct edges without a lobulate appearance appeared in all cases.Angular interface was present in five lesions,just like ice-cream cone. All lesions were heterogeneous on both unenhanced and dynamic contrast MSCT,without calcification. The majority of lesions were demonstrated the pattern of ＂rapid wash-in and slow wash-out＂contrast-enhanced CT features. Enlarged vessels were present in four larger lesions（ the largest diameter larger than or equal to 39 mm） and absent in two smaller lesions（ the largest diameter smaller than or equal to 20 mm）. Five lesions demonstrated macroscopic fat on MSCT. None of the EAMLs showed evidence of local invasion,vascular involvement,or distant metastases. Conclusion Renal EAML can have a range of imaging appearances and can be indistinguishable from renal cell carcinoma and typical angiomyolipoma. EAMLs may or may not demonstrate macroscopic fat. Those with macroscopic fat do not possess any CT imaging characteristics that allow them to be distinguished from typical angiomyolipomas. EAMLs without macroscopic fat are indistinguishable from renal cell carcinomas. The final diagnosis will depend on the histopathological examination.