[Angiomyolipoma of the kidney--value of imaging procedures].

The angiomyolipoma of the kidney is composed by blood vessels, smooth muscle tissue, and fat. It is important to differentiate this benign tumor from a malignant one. Two cases demonstrate the diagnostic value of the different imaging procedures. In 'typical' cases computed tomography shows the density of fat; histological examination is not necessary and follow up control with ultrasonography is sufficient. In other cases with a low part of fat histological examination cannot be missed. Angiography is not helpful for the differentiation from a malignant tumor.