摘要
BACKGROUND Minimal-fat angiomyolipoma(mf-AML)is often misdiagnosed as renal cell carcinoma before surgery.AIM To analyze the magnetic resonance imaging(MRI)features of mf-AML and the causes of misdiagnosis by MRI before operation.METHODS A retrospective analysis was performed on ten patients with mf-AML confirmed by surgical pathology,all of whom underwent preoperative MRI examination to analyze the morphological characteristics and MRI signals of the tumor.RESULTS MRI revealed a circular-like mass in 4/10(40%)patients,an oval mass in 6/10 patients(60%),a mass with a capsule in 9/10 patients(90%),and a mass with a lipid component in 7/10 patients(70%).The diameter of the masses in all ten patients was from 11 to 47 mm;the diameter was between 11 mm and 40 mm in 8/10(80%)patients and between 40 mm and 47 mm in 2/10(20%)patients.CONCLUSION An oval morphological characteristic is strong evidence for the diagnosis of mf-AML,while a capsule and lipids are atypical manifestations of mf-AML.