Vascular Anomalies

What are vascular anomalies?

Vascular anomalies are birthmarks or growths made up of blood vessels that have developed incorrectly. These growths can cause functional or cosmetic problems and may be composed of arteries, veins, capillaries, lymph vessels, or any combination of these.

While many vascular anomalies are present at birth, others do not appear until later in a child’s life, even into the teenage years. Vascular anomalies are common, with some vascular tumors such as hemangiomas occurring in 1 out of every 10 full term births.

Types of vascular anomalies

Vascular anomalies are grouped into two main categories: vascular tumors and vascular malformations. Although these lesions often look very similar, they are unique conditions that require different treatment methods.

Vascular tumors

There are many types of vascular tumors. The majority are benign. By far the most common type of vascular tumors are infantile hemangiomas, which typically grow for 6 to 12 months and then begin to shrink (regress).

Types of vascular tumors include:

Vascular malformations

Vascular malformations are present at birth, though they may not be obvious for several years. They are often named according to the type of blood vessel that is most affected.

Types of vascular malformations include:

  • Capillary vascular malformations (port-wine stains)
  • Arterial malformations (abnormal arteries)
  • Venous malformations (abnormal veins)
  • Arteriovenous malformations (abnormal arteries and veins)
  • Lymphatic malformations (abnormal lymphatics, or lymph vessels, which can lead to enlarged water-filled cysts and swelling)
  • Spider angiomas (arteries that show on the surface of the skin with a central red dot and outer branches)
  • Angiofibromas (pink, raised skin bumps seen in patients with tuberous sclerosis, formerly called adenoma sebaceum)
  • Complex combined malformations (sometimes accompanying a genetic syndrome), including:
    • Sturge-Weber syndrome (port wine stain in the upper third of the face, with eye and central nervous system involvement)
    • Klippel-Trenaunay syndrome (abnormal capillaries, veins, and lymphatics with overgrowth of the involved area of the body)
    • Parkes-Weber syndrome (port wine stain with arteriovenous malformation and overgrowth of the involved area of the body)
    • Hereditary hemorrhagic telangiectasia (may have nose and GI bleeding from small dilated vessels)
    • CLOVES syndrome (a collection of conditions that may include congenital lipomatous overgrowth, vascular malformations, epidermal moles, and spinal abnormalities)
    • Proteus syndrome (vascular malformations and overgrowth of body parts)

Patients that present with vascular malformations will receive multidisciplinary care to ensure coordinated treatment for all of their symptoms.


Vascular anomalies are caused by disorders in vascular development. These disorders during development lead to an increased number of abnormally twisted and enlarged blood vessels collecting in a single location.

The majority of vascular anomalies occur without any family history and are not inherited. There are some rare forms, though, that are inherited. Genetic defects have been identified in several of these conditions. If a genetic condition is suspected, your child’s evaluation may include consultation with a geneticist and genetic testing.

Signs and symptoms

The signs and symptoms of a vascular anomaly will depend on the type of anomaly your child has.

Vascular anomalies can cause:

  • Pain
  • Swelling
  • Bleeding
  • Infection
  • Obstruction
  • Ulceration
  • Misshapenness or overgrowth of the involved region, particularly in the extremities, hands and feet

Depending on their location, they can also be associated with abnormal growth of the affected part of the body.

Vascular malformations are present throughout a person’s lifetime and will slowly grow in proportion to your child’s growth. Hormonal changes during puberty may cause these lesions to grow. They may also get larger due to trauma or infection. 

Superficial vascular malformations — those that occur on the surface of the skin — are often pink, red, blue or purple. Deeper malformations may not show any color change to the skin. In both cases, swelling of the affected area may be visible.

Vascular malformations can cause pain in sensitive areas such as the feet and hands, which can impair walking and hand movement. Malformations may also cause swelling and enlargement of the arms, legs, and genitals. Facial malformations can cause swelling or distortion of the face, or tongue swelling and problems with speaking.


Most vascular anomalies can be diagnosed with a thorough health history and physical examination.

Imaging tests can provide additional information about the extent of the anomaly and help confirm the diagnosis. These tests can also help your child’s doctor determine which type of vascular anomaly he has. Ultrasound and MRI are the tests most commonly used, but catheter angiography or other imaging studies may also be recommended.

A growth can also be biopsied, but this is rarely needed to diagnose the anomaly.


Your child’s healthcare team will recommend a treatment approach based on the type of vascular anomaly she has. Because these conditions can be complex to manage, it’s important to seek treatment at a center that offers the full range of care and specialists your child may need, such as The Children’s Hospital of Philadelphia’s Vascular Anomalies Program. Our program offers multidisciplinary care for the long-term treatment of blood vessel abnormalities of the face and body.

If the anomaly is not causing your child any pain or discomfort, is not interfering with her functioning, or presenting any other complications, intervention may not be needed.

The primary treatment for problematic lymphatic and venous malformations is often sclerotherapy. This involves injection of the lesion with a substance designed to shrink the lesion. Surgical debulking (removal of part of the lesion) may also be required for bulky lesions. Complex malformations may also be successfully managed with medication such as Rapamycin, an immunosuppression drug that also has the ability to control blood vessel growth.

Arteriovenous malformations are often difficult to treat as they may progress extensively and have high recurrence rates. Treatment can include embolism via catheter angiography and surgical resection. Intervention is determined by the size and location of the lesion, the child’s age, and the stage of the lesion.

Certain vascular tumors (i.e. hemangiomas) respond to treatment with medications, which may include corticosteroids or beta blockers, or in rarer cases, chemotherapeutic medication.

Some vascular tumors may require surgery. For example, hemangiomas that do not shrink completely can be surgically reduced in size or completely removed. Any leftover small blood vessels in the skin (telangectasias) can be treated with pulse dye laser.

When considering surgical intervention for any vascular anomaly, the postoperative scar or deformity is weighed against the preoperative appearance of the malformation.

Long-term outlook

Making a correct diagnosis is extremely important in determining the long-term outlook for children with vascular anomalies.

In many cases, once a vascular tumor such as a hemangioma shrinks, it will not regrow — the regression is permanent. However, up to 30 percent of hemangiomas will not completely shrink. In these cases, children may have remaining soft tissue lumps, loose skin and blood vessels. Any leftover fibrofatty tissue or overlying skin color changes can be addressed as needed with surgery or laser therapy.

Unlike tumors, vascular malformations do not spontaneously shrink. Vascular malformations grow proportionately with your child’s growth. They may remain asymptomatic, or progress to cause problems. If there are no symptoms, intervention may not be needed. Symptomatic lesions may require multiple staged interventions over time.

Follow-up care

Vascular anomalies can be complicated. It is important for children with vascular anomalies to be followed by an experienced medical team in a dedicated center that can provide the interdisciplinary care your child may need.

Many lesions require expertise from multiple specialties, including plastic surgery, dermatology, interventional radiology, diagnostic radiology, general pediatric surgery, hematology, oncology, orthopedic surgery, oculoplastic surgery, ophthalmology and genetics. Receiving follow-up care through a program like CHOP’s Vascular Anomalies Program will ensure your child receives the accurate diagnosis and expert care she needs.

Reviewed by David W. Low, MD,