Angiomyxolipoma (vascular myxolipoma) of the knee in a 9-year-old boy.

Angiomyxolipoma (vascular myxolipoma) is a very rare variant of lipoma. This tumor is characterized by mature adipose tissue mixed with myxoid stroma and vascular vessels. To date, nine cases have been reported, all of them occurring in adults. Herein, we report a unique case of a 9-year-old boy presenting with a solitary painful mass on the right medial thigh and illustrate the imaging characteristics of this rare tumor.