What type of tumor is a hemangioma, and where is it commonly found?

A hemangioma is classified as a benign tumor that originates from blood vessels, specifically endothelial cells that line the blood vessels. These tumors are often characterized by their proliferation of capillaries and are typically found in areas of the skin that are frequently exposed to sunlight. This is particularly relevant in species like dogs and cats, where hemangiomas can appear on areas of the skin such as the ears, nose, and other sun-exposed regions. Being benign, hemangiomas generally have a favorable prognosis and are less likely to metastasize compared to malignant tumors.

The context of hemangiomas being benign tumors of blood vessels on sun-exposed skin is crucial, as it highlights the biological behavior of these tumors and their common clinical presentations in small animals.