What is the likely diagnosis for a 3-month-old infant with a red, vascular growth on the back?

A hemangioma is the most likely diagnosis for a 3-month-old infant presenting with a red, vascular growth on the back. Hemangiomas are benign vascular tumors that typically appear in infancy and are characterized by a raised, red or purplish lesion due to an overgrowth of blood vessels. These lesions are most commonly found on areas like the head, neck, and trunk but can occur anywhere on the body.

In the case of an infant, a hemangioma is the leading consideration because they can grow rapidly in the first few months of life and then usually undergo involution, shrinking in size and fading in color over time.

In contrast, a pigmented nevus, commonly known as a mole, typically presents as a darker, flat, and pigmented lesion, which does not match the description of a red, vascular growth. A salmon patch (stork bite) refers to a type of flat, pink mark that is often seen on the back or neck of newborns, but it is less raised and not typically described as a vascular growth. Malignant melanoma is quite rare in infants and usually appears as a dark, irregularly shaped lesion rather than a vascular one. Thus, hemangioma stands out as the