Glomuvenous Malformation

A glomuvenous malformation (GVM) is a type of vascular malformation formed by an abnormal growth of blood vessels and the presence of glomus cells in the wall of the malformation.

While they may be present at birth, they can also appear at any age and tend to be hereditary. Without treatment, GVMs change in appearance over time, becoming thicker and darker in color.

Glomuvenous malformations typically appear on the skin, most commonly on fingers and toes. In some cases, they can involve the mucous membranes, such as the inside of the mouth or extend into fat and muscles.

At first, a glomuvenous malformation looks like a raised pink or blue patch that feels bumpy to the touch. Over time, they tend to thicken and become more bluish in color, resembling a raised bruise.

These malformations vary in size and may develop at any age. GVMs can be painful with or without touch. Pain may be caused by:

• Getting bumped or hit
• Direct pressure
• Extreme temperature changes (because they are associated with an abnormal growth of cells that regulate body heat)

Sclerotherapy, surgery, and medications are treatment options that relieve and reduce pain.

Glomuvenous malformations are frequently hereditary. Researchers have identified mutations in the glomulin gene in the majority of GVM cases. If a child has a hereditary form, it means at least one parent carries the mutated gene.

While GVMs may run in families, they can present differently from one person to the next. Some family members may have less prominent lesions, while another may have multiple or extensive malformations.

Your visit will start with a complete medical history and a physical exam. In most cases, the physician will be able to diagnose your child’s glomuvenous malformation with a thorough examination. However, further testing will be necessary to determine the extent of the disease and therefore the best treatment course.

The best imaging test for seeing deeper lesions is an MRI (magnetic resonance imaging). An MRI is a high-resolution scan that shows the exact location and depth of your child’s malformation and can identify abnormalities in nearby blood vessels.

Our team uses this information to develop customized treatment plans that will best target your child’s GVM.

Treatment depends on how many lesions your child has, as well as their size, location, and severity.

The primary goal of treatment is to relieve your child’s symptoms, such as the pain often associated with GVMs.

Our team will surgically remove a glomuvenous malformation whenever possible. However, because many GVMs tend to be large, deep, or spread out, your child’s treatment course may include other options to shrink and lighten the lesion.

Treatments may include:

• Sclerotherapy: This minimally invasive (non-surgical) treatment involves injecting a liquid medication into a vascular malformation that causes it to shrink over time.
• Medication (sirolimus): This oral medication is an immunosuppressant that improves symptoms, including pain, and improves skin appearance. After treatment with sirolimus, GVMs tend to be softer and less discolored.
• Surgery: Patients with small GVMs that can be completely removed are candidates for surgery.
• Pulsed dye laser: This treatment uses a laser device that destroys abnormal blood vessels without damaging surrounding skin. It does not penetrate into deeper layers of the skin.

Prognosis varies from one person to the next, depending on the size, location, and severity of the malformations.

Because GVMs tend to become darker and thicker over time, they respond best to treatment when diagnosed early. Not all GVMs respond to treatments the same way. That is why our customized treatment approach takes into account your child’s unique needs and makes adjustments as needed.

We treat children with glomuvenous malformations in our Vascular Anomalies Center, considered a premier center in the world for all types of vascular malformations.

Families choose us because we offer:

• Nationally recognized expertise: Families travel to us from all over the country because of our reputation for experience. As a national referral center, we have diagnosed and treated more cases of glomuvenous malformation than any other hospital.
• Comprehensive team approach: At the Vascular Anomalies Center, patients and their families benefit from a team of specialists working together to develop a customized treatment plan for your child. Our clinic brings together the expertise of many fields including hematology/oncology, dermatology, and interventional radiology (minimally invasive treatments) surgery.
• Expert diagnosis: Some cases of GVM may be misdiagnosed as hemangioma or venous malformation. We offer a definitive diagnosis that determines the exact location and depth of the lesions for the most targeted treatment possible.
• Leaders in advanced treatments: Members of our team have unmatched experience with many of the top GVM treatments. Our hematologists were among the first to study and prescribe medications such as sirolimus for vascular malformations and are experts in precise dosing for the best possible results.

At Boston Children’s Hospital, our Vascular Anomalies Center team is known for its expertise in diagnosing and treating multiple and extensive glomuvenous malformations in infants and children of all ages.

For decades, our center has collaborated with genetic researchers in Belgium to understand the genetic causes of vascular malformations. This work led to the discovery of the gene responsible for glomuvenous malformation. Read more about research and innovation at the Vascular Anomalies Center.