Vascular malformations are abnormal formations of blood vessels present at birth, resulting from irregularities in arteries, veins, capillaries, or lymphatic vessels during fetal development. They are not cancerous and do not spread to other parts of the body, unlike tumors. While some may be immediately apparent, others can become noticeable later in childhood or even adulthood.
What They Are
Vascular malformations represent structural defects in the formation of blood vessels, resulting from errors during embryonic development. Instead of forming smooth, organized networks, the vessels in these malformations can enlarge, tangle, or create abnormal connections, leading to irregular blood flow. This underlying developmental anomaly means they are present from birth, even if not immediately visible.
It is important to distinguish vascular malformations from hemangiomas, which are another type of vascular anomaly. Hemangiomas are benign tumors that appear shortly after birth, grow rapidly, and then often disappear on their own over several years. In contrast, vascular malformations grow proportionally with the child, do not regress spontaneously, and persist throughout a person’s life.
Vascular malformations are categorized based on the type of blood vessel involved:
- Capillary malformations, often known as port-wine stains, are flat, pink or purple patches on the skin.
- Venous malformations involve abnormally formed veins and are the most common type, appearing as soft, bluish lumps.
- Lymphatic malformations occur when lymphatic vessels are malformed, leading to fluid-filled cysts.
- Arteriovenous malformations (AVMs) are characterized by abnormal direct connections between arteries and veins, bypassing the capillaries, and are considered high-flow lesions.
While the exact cause of vascular malformations is often unknown, they are generally thought to arise from sporadic errors in vascular development during pregnancy, rather than being commonly inherited. However, some types can be associated with genetic syndromes.
Recognizing Vascular Malformations
The signs and symptoms of vascular malformations vary depending on their type, size, and location. Those on the skin might appear as discolored patches, such as the red or purple marks of capillary malformations. Venous and lymphatic malformations often present as soft tissue masses, lumps, or swelling under the skin. Venous malformations may feel soft and compressible when pressed.
Beyond visible changes, vascular malformations can cause a range of symptoms. Individuals might experience pain, warmth, or pulsation, particularly with arteriovenous malformations due to their high blood flow. Depending on the location, they can also lead to functional issues, such as impaired movement in a limb or affecting swallowing or vision if in the head or neck. Bleeding or fluid leakage from skin lesions can also occur.
Diagnosis of vascular malformations begins with a clinical examination by a specialist. Imaging studies then visualize the malformation’s extent and type. Magnetic Resonance Imaging (MRI) is frequently used for detailed soft tissue images and to differentiate malformation types, including high-flow and low-flow lesions, while Magnetic Resonance Angiography (MRA) or Computed Tomography (CT) scans may also assess blood vessels. For certain cases, particularly AVMs, an angiography may be performed, involving dye injection to outline blood vessels and provide a clearer view. Early and accurate diagnosis by a specialized team is important for developing an appropriate management plan.
Treatment Options
Treatment for vascular malformations is individualized, considering the specific type, size, location, and symptoms. Small, asymptomatic malformations might only require careful observation. The goal of treatment often focuses on managing symptoms, reducing malformation size, and preventing complications.
Medical management can involve medications, such as sirolimus, used for certain lymphatic or venous malformations to help reduce their size. Pain management is also provided for symptomatic malformations. Procedures like sclerotherapy involve injecting a sclerosant solution directly into the malformation. This substance irritates the lining of abnormal vessels, causing them to scar, collapse, and shrink. Sclerotherapy is commonly used for venous and lymphatic malformations.
Embolization is another treatment option, a minimally invasive procedure where a substance is injected to block blood flow to the malformation. This technique is often used for arteriovenous malformations (AVMs) to reduce symptoms like pain and swelling. Laser therapy is employed for superficial malformations, such as port-wine stains, to reduce discoloration. Lasers can also be combined with other treatments for more complex malformations.
Surgical excision, which involves physically removing the malformation, is considered when feasible and safe. This approach may be used alone or with other treatments, especially for localized malformations. Often, a combination of treatments is used for effective management. Managing vascular malformations frequently involves a multidisciplinary team of specialists, including dermatologists, interventional radiologists, surgeons, and neurologists, to provide comprehensive care. Long-term management and surveillance are often necessary, as malformations can change over time, sometimes requiring re-evaluation and additional treatment.