Venous Malformations | Symptoms and Causes

What are the symptoms of venous malformations?

Venous malformations (VMs) most commonly appear on the skin but can be present in other tissues and organs as well. They are typically blue, soft and compressible.

They can range in size from a very small lesion in one spot to widespread lesions that also affect the underlying tissue, muscles and bones. They can also arise on their own, or as part of an underlying condition like blue rubber bleb nevus syndrome.

VMs can appear anytime during childhood, adolescence or adulthood. Most are present at birth, though they may not be apparent or diagnosed until later — especially if the malformation is small or not in an obvious location.

The symptoms of a VM depend on the malformation's size and location and most commonly include:

  • pain
  • swelling
  • psychological/social issues related to the appearance of the lesion

What causes venous malformations?

VMs are caused by genetic mutations that arise during the embryonic stage of life. No known food, medication or activity during pregnancy can cause a VM.

What are the most common venous malformation complications?

Some possible complications include:

  • pain when the VM suddenly expands if a clot forms
  • growth as the result of injury or during puberty
  • obstruction of vital functions like breathing or vision
  • fractures of the affected bone and arthritis with limbs impacted by VMs
  • a pulmonary embolism if a large VM affects a child’s deep venous system
  • chronic bleeding and anemia with gastrointestinal VMs