Fibro-adipose vascular anomaly

{{Infobox medical condition (new)

| name =

| synonym = FAVA

| image =

| image_size =

| alt =

| caption =

| pronounce =

| specialty = Pediatrics, interventional radiology,

| symptoms = Pain, difficulty moving the affected limb, contracture, mild enlargement of the affected limb

| complications =

| onset = Later childhood to young adulthood

| duration =

| types =

| causes = Unknown, potentially genetic

| risks =

| diagnosis = Ultrasound, MRI

| differential =

| prevention =

| treatment = Physical therapy, surgical resection, cryoablation

| medication = Sirolimus

| prognosis =

| frequency = rare

| deaths =

}}

Fibro-adipose vascular anomaly, also known as FAVA, is a type of vascular anomaly that is both rare and painful. FAVA is characterized by tough fibrofatty tissue taking over portions of muscle, most often contained within a single limb. FAVA also causes venous and/or lymphatic abnormalities.

Though FAVA has only been recognized as a distinct vascular anomaly, separate from common venous malformations, within the past ten years, FAVA a distinct congenital disorder.

Signs and symptoms

Common symptoms of FAVA include severe pain and difficulty moving the affected limb, mild enlargement of the affected limb with visible veins, and contracture.{{Cite web|url=http://www.childrenshospital.org/conditions-and-treatments/conditions/f/fibro-adipose-vascular-anomaly|title=Fibro-Adipose Vascular Anomaly (FAVA) {{!}} Boston Children's Hospital|website=www.childrenshospital.org|access-date=2020-01-31}}

In the cohort described by Alomari et al.{{cite journal | vauthors = Alomari AI, Spencer SA, Arnold RW, Chaudry G, Kasser JR, Burrows PE, Govender P, Padua HM, Dillon B, Upton J, Taghinia AH, Fishman SJ, Mulliken JB, Fevurly RD, Greene AK, Landrigan-Ossar M, Paltiel HJ, Trenor CC, Kozakewich HP | s2cid = 22919252 | display-authors = 6 | title = Fibro-adipose vascular anomaly: clinical-radiologic-pathologic features of a newly delineated disorder of the extremity | journal = Journal of Pediatric Orthopedics | volume = 34 | issue = 1 | pages = 109–17 | date = January 2014 | pmid = 24322574 | doi = 10.1097/BPO.0b013e3182a1f0b8 }} from the Vascular Anomalies Center at Boston Children's Hospital, FAVA was located, in descending order, in the calf, forearm/wrist and thigh. The most common presentation is severe pain. Calf lesions, particularly those located in the posterior compartment, are commonly associated with restricted ankle dorsiflexion (equinus contracture).{{citation needed|date=June 2020}}

Genetics

No one knows what causes FAVA, though recent research revealed mutations in a gene called PIK3CA in some—but not all—cases.{{cite journal | vauthors = Luks VL, Kamitaki N, Vivero MP, Uller W, Rab R, Bovée JV, Rialon KL, Guevara CJ, Alomari AI, Greene AK, Fishman SJ, Kozakewich HP, Maclellan RA, Mulliken JB, Rahbar R, Spencer SA, Trenor CC, Upton J, Zurakowski D, Perkins JA, Kirsh A, Bennett JT, Dobyns WB, Kurek KC, Warman ML, McCarroll SA, Murillo R | display-authors = 6 | title = Lymphatic and other vascular malformative/overgrowth disorders are caused by somatic mutations in PIK3CA | journal = The Journal of Pediatrics | volume = 166 | issue = 4 | pages = 1048–54.e1–5 | date = April 2015 | pmid = 25681199 | pmc = 4498659 | doi = 10.1016/j.jpeds.2014.12.069 }} PIK3CA is a gene in the receptor tyrosine kinase phosphatidylinositol 3-kinase (PI3)-AKT growth-signaling pathway. The PIK3CA gene is located on the long (q) arm of chromosome 3.{{cite web | work = Genetics Home Reference | url = http://ghr.nlm.nih.gov/gene/PIK3CA | title = PIK3CA }}

There has been no evidence to suggest that FAVA is inherited or passed along in families.

Diagnosis

FAVA is most often diagnosed in older children, teens and young adults, though it has been diagnosed earlier and later in a patient's life.

The constellation of clinical, radiologic, and histopathologic findings typically allow the diagnosis of FAVA.{{Cite web|url=http://www.childrenshospital.org/conditions-and-treatments/conditions/f/fibro-adipose-vascular-anomaly/diagnosis-and-treatment|title=Fibro-Adipose Vascular Anomaly (FAVA) {{!}} Diagnosis & Treatment {{!}} Boston Children's Hospital|website=www.childrenshospital.org|access-date=2020-01-18}} The most helpful imaging studies are ultrasonography (US) and magnetic resonance imaging (MRI). The major imaging features of FAVA include the presence of complex intramuscular solid lesion replacing normal muscle fibers with fibrofatty overgrowth and phlebectasia. The extrafascial part is composed of fatty overgrowth, phlebectasia, and occasional lymphatic malformation.

The histopathologic findings in FAVA include dense fibrous tissue, fat, and lymphoplasmacytic aggregates within atrophied skeletal muscle. Adipose tissue within skeletal muscles are associated with large, irregular, and sometimes excessively muscularized venous channels and smaller, clustered channels. Organizing thrombi, lymphatic foci and enlarged nerves encircled by dense fibrous tissue are also frequently noted in FAVA.{{citation needed|date=October 2021}}

Management

Some FAVA patients develop limb contracture; in these cases early orthopedic consultation is necessary. Achilles tendon lengthening (heel-cord release) and physical therapy can be helpful for treating equinus contracture.{{Cite journal|last1=Fernandez-Pineda|first1=Israel|last2=Marcilla|first2=David|last3=Downey-Carmona|first3=Francisco Javier|last4=Roldan|first4=Sebastian|last5=Ortega-Laureano|first5=Lucia|last6=Bernabeu-Wittel|first6=Jose|date=2014|title=Lower Extremity Fibro-Adipose Vascular Anomaly (FAVA): A New Case of a Newly Delineated Disorder|url=https://www.jstage.jst.go.jp/article/avd/7/3/7_cr.14-00049/_pdf/-char/en|journal=Annals of Vascular Diseases|volume=7|issue=3|pages=317|doi=10.3400/avd.cr.14-00049|pmid=25298836|pmc=4180696}}

Unlike classical venous malformations, pain in FAVA is multifactorial and clinical response to sclerotherapy of the venous component can be less effective.{{Cite journal|last1=Fernandez-Pineda|first1=Israel|last2=Marcilla|first2=David|last3=Downey-Carmona|first3=Francisco Javier|last4=Roldan|first4=Sebastian|last5=Ortega-Laureano|first5=Lucia|last6=Bernabeu-Wittel|first6=Jose|date=2014|title=Lower Extremity Fibro-Adipose Vascular Anomaly (FAVA): A New Case of a Newly Delineated Disorder|url=https://www.jstage.jst.go.jp/article/avd/7/3/7_cr.14-00049/_pdf/-char/en|journal=Annals of Vascular Diseases|volume=7|issue=3|pages=319|doi=10.3400/avd.cr.14-00049|pmid=25298836|pmc=4180696 |doi-access=free}} While intralesional steroid injections and nerve block may offer temporary or partial pain relief, the source of pain is often the solid intramuscular lesion. Surgical resection and image-guided percutaneous cryoablation may offer an effective control of pain in FAVA lesions.{{cite journal | vauthors = Shaikh R, Alomari AI, Kerr CL, Miller P, Spencer SA | s2cid = 20061278 | title = Cryoablation in fibro-adipose vascular anomaly (FAVA): a minimally invasive treatment option | journal = Pediatric Radiology | volume = 46 | issue = 8 | pages = 1179–86 | date = July 2016 | pmid = 26902298 | doi = 10.1007/s00247-016-3576-0 }} Sirolimus has been effective in improving the quality of life in some people with FAVA.{{cite journal | vauthors = Erickson J, McAuliffe W, Blennerhassett L, Halbert A | s2cid = 20625518 | title = Fibroadipose vascular anomaly treated with sirolimus: Successful outcome in two patients | journal = Pediatric Dermatology | volume = 34 | issue = 6 | pages = e317–e320 | date = November 2017 | pmid = 29144050 | doi = 10.1111/pde.13260 }}

Fibro-adipose vascular anomaly

Signs and symptoms

Genetics

Diagnosis

Management

References

Further reading