How do I know what kind of pigmented lesion I have?

Classification of congenital vascular birthmarks has historically been confusing. The medical literature has been inundated by an assortment of terminologies, including hemangioma, nevus flammeus, "stork bites" and port-wine stains. Hemangioma became the generic term used to describe a variety of acquired and congenital vascular lesions. Because this classification was so broad, however, it led to confusion regarding prognosis.

Lesions that develop by undergoing an initial phase of rapid proliferation followed by cessation of growth and involution are classified as hemangioma. Vascular birthmarks that persist throughout the patient's lifetime and grow commensurately are classified as vascular malformation; this group includes port-wine stains.

Hemangiomas tend not to be present at birth but appear during the first few days to weeks of life, often as single small macules. These lesions grow rapidly, becoming red and raised. The lesions increase in size during the following weeks to months, until the child reaches about 12 months of age, when growth stops. Hemangiomas occur most frequently on the face or neck and tend to vary in size from a few millimeters to many centimeters in diameter.

The fully developed hemangioma is often dome-shaped, ranging in color from bright red to dark purple. Approximately 50 percent of hemangiomas spontaneously involutes (diminish) by the time the child is five years of age. Vascular malformations (port-wine stains) are almost always present at birth and occur with equal frequency in males and females.

The port-wine or red color of these lesions is a consequence of enlarged, ectatic (expansion) blood vessels in the dermis, rather than an increase in the number of blood vessels. The incidence of port-wine stains is estimated to be 0.3 percent; 80 to 95 percent are located on the head and neck. Most port-wine stains appear to involve only the skin; however, approximately 5 percent of patients with port-wine stains have concomitant leptomeningeal involvement (Sturge-Weber syndrome) and/or ocular involvement.

At birth, port-wine stains appear as pale pink macules. They darken with age, becoming red to purple, and often develop small nodules within the birthmark, which give the lesions a studded appearance. In extensive lesions, hypertrophy of underlying soft tissues often occurs. These lesions result from blood vessels which become enlarged (or dilated), such as port-wine stains (red birthmarks like Mikhail Gorbachev's) or spider veins. They can also appear when too many blood vessels grow in an area, such as hemangiomas.