What is a Venous Malformation? 

Venous malformations occur when veins do not properly form. They may include vessels that are irregular or enlarged and may lack the valves that prevent backflow in normal venous structures. Sometimes these vascular anomalies appear as small, bluish lesions in the skin. In other patients, they may also involve larger abnormal vessels, which can pose a risk for blood clots. Venous malformations may involve any body area and may be limited to the skin or arise in deeper tissues. They may also be found in conjunction with lymphatic malformations in some patients (mixed vascular malformations).

Although the exact cause is unknown, physician-scientists have found that improper assembly of the smooth muscle cells normally forming the outer layer of veins can result in venous malformations in some cases. In other instances, venous malformations may be associated with other vascular anomalies, such as glomuvenous malformations or blue rubber bleb nevus syndrome.

Signs & Symptoms

Venous malformations typically are present at birth. Because they often get larger over time, as a child grows, a patient may not notice them or have any symptoms until childhood or adolescence. Venous malformations appear as bluish-purple marks that feel soft to the touch. When compressed, blood empties from the area and the malformation may look smaller or lighter in color. Symptoms vary based on the size and location of the malformation(s) and may include pain and/or swelling.


Physicians can usually diagnose venous malformations based on a patient's medical history and a physical examination. In addition, imaging studies may provide more information about the extent of the lesion(s).


Treatment for venous malformations depends on the size and location of the lesion(s). Smaller malformations that occur on the skin's surface and do not cause pain may only require observation. Treatment for symptomatic, larger or more extensive lesions may include:

  • Compression garments to reduce swelling
  • Surgical removal of the malformation
  • Sclerotherapy, the injection of a solution directly in the vein, which causes it to collapse

The vascular anomalies team will recommend the best treatment option for your child's venous malformation.

Why Choose Us?

The vascular anomalies program at Comer Children's offers an integrated and comprehensive approach to the diagnosis, care and management of vascular malformations. Our multidisciplinary team of pediatric experts works together to educate families and to evaluate and treat children with all types of these vascular lesions.

Resources & Support for Patients with Vascular Anomalies

Patient Resources at Comer Children’s

Kids want to feel like kids, even when they're sick. Our Child Life therapists use play, art and other approaches to take some of the scare away from the hospital experience and to help kids feel as normal as possible, in spite of their disease. Located near Comer Children's, the Ronald McDonald House provides a home away from home for families while their child is hospitalized.

Patient Resources & Support Groups

These organizations and support groups may be helpful to families and patients by providing support, education and treatment information on vascular anomalies.