Fibro-Adipose Vascular Anomaly (FAVA)

What is FAVA?

Fibro-adipose vascular anomaly (FAVA) is a rare, but painful, vascular anomaly in which a significant portion of a muscle in one of a child's limbs is taken over by tough, fibrous, fatty tissue. In addition to muscle tissue changes, FAVA can also cause abnormalities in the veins or lymphatic vessels. It has only been recognized as a distinct kind of vascular anomaly within the last couple of years.

What are the symptoms of FAVA?

The most common symptoms of FAVA are:

  • pain, often severe, in the affected limb
  • difficulty moving the affected limb and contracture (such as a fixed bending of the arm or flexing of the ankle)
  • mild enlargement of the limb with some visible veins

Patients have been diagnosed with FAVA anywhere between infancy and adulthood but the majority are older children, teens or young adults.

What causes FAVA?

No one knows what causes FAVA, though recent research revealed mutations in a gene called PIK3CA in some — but not all — cases. It appears to be a spontaneous condition, and is not inherited or passed along in families.

How we care for FAVA

Because FAVA was first identified as a unique condition by clinicians at Boston Children’s Hospital, we have the depth of knowledge to ensure an accurate diagnosis. Once a diagnosis and the extent of the disease are confirmed, the team at the Vascular Anomalies Center will work with you to develop a coordinated care plan that matches your child's specific needs. The team brings the expertise of other Boston Children's departments and services as necessary to provide your child with the best care in a family-friendly atmosphere.

Our areas of innovation for FAVA

Researchers and clinicians in the VAC conduct research that may lead to the development of new, more effective therapies and ways to prevent FAVA and other anomalies. Members of our team published the first paper that defined FAVA as a unique vascular anomaly, and recently identified mutations in a gene called PIK3CA in tissues from several patients with FAVA. Also, in a recent retrospective review study, VAC clinicians determined that image-guided percutaneous cryoablation (a procedure where a clinician partially freezes a FAVA lesion) is an effective and safe option for controlling pain associated with FAVA.