Definition Hemangioma, also known as infantile hemangioma (IH), is the most common benign tumor in infants and young children and is a true vascular tumor caused by overproliferation of normal vascular tissue in the mesoderm. It is a true vascular tumor caused by excessive proliferation of normal vascular tissue in the mesoderm. Hemangiomas are most common in the head, face and neck, followed by the extremities and trunk. The incidence is 1.1%-2.6% in newborns and about 30% can be seen at birth, usually growing slowly at 2 or 4 weeks after birth, thus the incidence is 10%-12% at the age of 1 year. Female infants are more common than male infants, with a ratio of 2 to 5:1, and multiple cases account for 15% to 30%. Clinical manifestations Most hemangiomas occur in the skin or subcutaneous tissues and are divided into proliferative, receding, and completed stages according to the process of lesion development. This typical feature is an important basis for its differentiation from vascular malformations. Although most hemangiomas can regress on their own, the rate of proliferation and regression is not the same.