Angiomyolipoma is commonly found in the forearms and lumbar region of the upper extremities and can be solitary or multiple. It consists mainly of a mixture of mature adipose tissue and abnormally proliferating active blood vessels, and can be nodular, plaque-like, diffusely infiltrating, or striated in clinical presentation. The texture is harder than that of lipoma, with internal pulsating sensation, usually 1-4 cm in diameter, and some patients have painful sensation when pressed. If the tumor grows gradually, it may cause compression and lead to dysfunction of the corresponding organs.