You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A lesion composed of microscopic vessels is called as: and explain in detail?
The term hemangioma traditionally has been used to describe a variety of developmental vascular anomalies. Currently, hemangiomas are considered to be benign tumors of infancy that display a rapid growth phase with endothelial cell proliferation, followed by gradual involution.
 
Ref: Nevilles oral and maxillofacial pathology 4th edition page 504