Vascular anomalies are abnormalities or disorders of the vascular system, either in veins or arteries. Vascular anomalies are classified as either a vascular tumor or a vascular malformation.

Blood is pumped through the body in tube-like structures called blood vessels. These vessels form a network. Some vessels, called arteries, pump the blood from the heart out to the body. Other vessels, called veins, bring blood back to the heart, where it gets oxygen from the lungs. The cells of the body use oxygen to make energy.

The body also has a network of lymphatic vessels. These vessels carry a clear fluid called lymph, which transport white blood cells in it. These white blood cells help fight infection and disease as part of the immune system.

Arteries, veins and lymphatic vessels have something important in common. They are all lined with a type of tissue called endothelium. Endothelium acts as a gatekeeper by letting some cells into the vessels and keeping other cells out. It also helps control blood pressure. This means that blood will travel faster or slower when needed.

These vessels and the endothelium that lines them are vital to the body’s health. Vascular anomalies are disorders of the endothelium and its associated blood vessels.

Vascular Tumors

While a baby is developing, the cells that line blood vessels can multiply more than is normal. The extra growth forms a complex mass (tumor). After birth, the cells can keep increasing and the mass can get bigger. The mass can be on the surface of the skin, deep under the skin or both. As the heart pumps blood out to the body, the spaces within the mass fill with blood. These masses are called vascular tumors.

Some vascular tumors have a growth cycle. They get bigger until they reach a maximum size. Then they slowly shrink. Often these vascular tumors resolve by themselves.

Some vascular tumors don’t need treatment because they can heal on their own. Others are treated with medication taken by mouth or applied to the skin. After the tumor shrinks, surgery can be done to remove any remaining mark.

Learn more about vascular tumors:

• Infantile hemangioma
• Congenital hemangioma

Vascular Malformations

Vascular malformations form when a baby is developing in the uterus. Instead of creating normal, smooth tube-like vessels, the vessels form into pockets, extra vessels or even shunting vessels (in the case of arteriovenous malformations/fistulae). Blood or lymph can collect here abnormally. This can cause swelling, infection and pain. Some kinds of vascular anomalies can even prevent parts of the body from getting the blood supply they need.

As a child grows, the vascular malformation will grow, too, and might start causing problems. Unlike some vascular tumors, vascular malformations don’t have a growth cycle and they won’t go away on their own.

Sclerotherapy is an effective treatment for vascular malformations. Surgery can be done to get rid of any mark or growth left on the skin after sclerotherapy treatment. Some vascular malformations can be managed with medications taken by mouth.

Vascular malformations can be classified into two main categories:

1. Low-flow malformations: venous, lymphatic and capillary malformations
2. High-flow malformations: arteriovenous malformations and arteriovenous fistulae