The diagnosis and management of vascular anomalies of the extremities can be challenging as these disorders are uncommon and may clinically overlap. The aim of this paper is to describe the clinical, radiologic, and histopathologic features of fibro-adipose vascular anomaly (FAVA), a previously unrecognized disorder of the limb.
The clinical, imaging, operative, and histopathologic data from patients with a unique intramuscular lesion of the extremities comprising dense fibrofatty tissue and slow-flow vascular malformations were retrospectively reviewed.
Sixteen patients diagnosed with FAVA of the extremity (3 male and 13 female individuals) met the clinical, radiologic, and histopathologic inclusion criteria. The age at presentation ranged from the time of birth to 28 years. The locations of the lesions were: calf (n=10), forearm/wrist (n=3), and thigh (n=3). Fourteen patients presented with severe pain. Seven of the patients with calf lesions had limited ankle dorsiflexion. On imaging, the complex intramuscular lesions replaced muscle fibers with fibrofatty overgrowth and phlebectasia (dilation of the veins). The extrafascial component comprised fatty overgrowth, phlebectasia, and an occasional lymphatic malformation. The histopathologic features comprised dense fibrous tissue, fat, and lymphoplasmacytic aggregates within atrophied skeletal muscle. Adipose tissue also infiltrated skeletal muscle at the periphery of the lesion. There were large, irregular, and sometimes excessively muscularized venous channels and smaller, clustered channels. Other findings include organizing thrombi, a lymphatic component, and dense fibrous tissue–encircled nerves.
The constellation of clinical, radiologic, and histopathologic features constitutes a distinct entity comprising fibrofatty infiltration of muscle, unusual phlebectasia with pain, and contracture of the affected extremity. The clinical and radiologic findings permit the diagnosis of FAVA with major therapeutic implications.
*Divisions of Vascular and Interventional Radiology
†Vascular Anomalies Center
Departments of ‡Orthopedic Surgery
∥Plastic and Oral Surgery
††Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA
§Department of Diagnostic and Interventional Imaging, Memorial Hermann and Memorial Hermann Children’s Hospital, Houston, TX
None of the authors received financial support for this study.
The authors declare no conflict of interest.
Reprints: Ahmad I. Alomari, MD, MSc, FSIR, Division of Vascular and Interventional Radiology, Children’s Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115. E-mail: firstname.lastname@example.org.