Abstract
Angiomyolipomas are the most common type of benign renal tumors and are characterized by a mixture of mature adipose tissue, sheet of smooth muscle, and thick-walled blood vessels of various proportions. Several cases of angiomyolipoma with partial malignant transformation invading the adjacent structure and lymph node have been reported. On the other hand, benign angiomyolipomas invading the adjacent structures has been rarely reported. We report a case of a benign angiomyolipoma with renal vein invasion.