Fibroadipose Vascular Anomaly (FAVA)

Overview

Fibroadipose vascular anomalies, also known as FAVA, is a special type of malformation which closely resembles intramuscular venous malformations.

This condition typically affects musculature, most commonly found in the calf muscles (70%) but also in other areas such as the thigh, forearm, gluteal region, and ankle or foot.

Symptoms and History

FAVA symptoms can appear at any age but typically manifest in adolescence/teenage years. FAVA is differentiated from typical venous malformations in that they are more commonly associated with pain (sometimes severe/debilitating) and can lead to contractures. FAVA can surround the nerves, leading to paresthesias (nerve pain).

Diagnosis

Clinical Exam. As discussed above, the patient may present with significant pain and contractures. Early manifestations are similar to venous malformations and the patient may just show mild fullness of the affected limb.

Imaging. On MRI (Magnetic Resonance Imaging) and ultrasound, FAVA has more fat and scar tissue component present than the typical spongiform channels seen with venous malformations.

Pathology. Histopathologically, FAVA is more infiltrative in the musculature and has greater fibroadipose tissue content compared to venous malformations

Genetics. Not much is yet known regarding genetics of FAVA

Treatment

FAVA can be treated in multiple ways:

  • Aggressive physical therapy can help to reduce the development of contractures
  • Steroid injections can help reduce inflammation/pain symptoms
  • Sclerotherapy can be performed if there are adjacent dilated veins and thrombosis present
  • Nerve block can be performed to reduce neurologic symptoms
  • More recently, a special therapy called cryoablation can be performed, which has been shown to help reduce symptoms of pain
  • Surgical resection can be performed to remove parts of the lesion to reduce pain
  • Medical therapy with sirolimus may be offered in complicated cases