Lower Extremity Fibro-Adipose Vascular Anomaly (FAVA): A New Case of a Newly Delineated Disorder

Abstract

The acronym FAVA (Fibro-Adipose Vascular Anomaly) has been recently given to a distinct vascular entity that is characterized by fibrofatty infiltration of muscle, unusual phlebectasia with pain, and contracture of the affected extremity. We report a new case of FAVA in a 10-year-old girl with pain in her right lower leg and equinus contracture. As in our case, FAVA typically presents in young females with calf involvement and limited ankle dorsiflexion with local pain. FAVA should be considered as a differential diagnosis when evaluating vascular anomalies in the lower extremities.

Keywords: Fibro-Adipose Vascular Anomaly; vascular anomalies; venous malformation.

Fig. 1

(A) Magnetic resonance imaging (MRI). Sagittal fat-saturated T1-weighted MRI following contrast administration demonstrating moderate enhancement of the lesion located in the gastrocnemius muscle. (B) Sclerotherapy. Phlebectasia (black arrow).

Fig. 2

Intraoperative findings. (A) Gastrocnemius muscle infiltrated by venous malformation (black arrow). (B) Specimen with venous malformation (black arrow) and fibroadipose tissue components (asterisk).

Fig. 3

Histological findings. (A) Cross section consisted of a variable admixture of dense fibro-fatty tissue and vascular clusters. The fibrous component was particularly prominent. (B) Clusters of vascular channels with a extensive fibro-fatty tissue, separating bundles of skeletal muscle. (C) Cluster of thin walled, back to back and empty or blood filled venous channels. (D) Anomalous lymphatic vascular component, supported by endothelial D2-40 inmunopositivity.