What are vascular and lymphatic malformations?

A vascular malformation is a tangle of abnormal vessels you’re born with. They are not cancer, and they are not contagious — but they grow with you, and they can cause real problems. The major types are:

• Venous malformations (VMs) — the most common type. Soft, often bluish areas under the skin or deep inside muscle that can be painful and swell with activity or hormonal changes.
• Lymphatic malformations (LMs) — pockets of abnormal lymph fluid, often in the neck, armpit, or chest. Can be small fluid-filled cysts or large clusters.
• Arteriovenous malformations (AVMs) — abnormal direct connections between arteries and veins. Higher-flow and trickier to treat.
• Capillary malformations (port-wine stains) — flat skin marks present at birth.
• Combined and syndromic conditions — including Klippel-Trenaunay syndrome (KTS), CLOVES, PROS (PIK3CA-related overgrowth spectrum), Parkes Weber, Sturge-Weber, and others.

A team built for these conditions

The single most important thing a center of excellence offers is a multidisciplinary team that meets regularly — not specialists treating in silos and writing letters back and forth. For our patients, that means coordinated care across interventional radiology, vascular surgery, plastic surgery, dermatology, hematology, medical genetics, and pain medicine. Complex and recurrent malformations that smaller centers typically refer out are exactly the cases we’re built to handle.

A full range of advanced procedures

For most venous and lymphatic malformations, the mainstay treatment is image-guided sclerotherapy — a tiny needle is placed directly into the abnormal vessels under live ultrasound and X-ray, and a medication is injected to scar them down. The medication is chosen for the specific malformation; common choices include bleomycin, doxycycline, ethanol, sodium tetradecyl sulfate (STS), and — for certain large lymphatic cysts — OK-432 (picibanil). For arteriovenous malformations, we use embolization with medical-grade glue, Onyx, coils, or vascular plugs. Laser therapy and cryoablation round out the options. Most malformations are treated over multiple sessions as the malformation responds.

Genetic testing and targeted therapy

One of the most exciting advances in vascular anomalies care over the last decade is the discovery that many of these conditions are driven by specific somatic mutations — small genetic changes in the malformation itself, not inherited from parents. The most common is PIK3CA, but TIE2, RASA1, GNAQ, and others all have their place. Identifying the driver mutation can open up targeted medical therapy — the mTOR inhibitor sirolimus for many complex VMs and LMs, and the PI3K-alpha inhibitor alpelisib for PIK3CA-driven conditions like PROS, KTS, and CLOVES. These options were not available a few years ago. They are part of standard care at a center of excellence.

Higher case volume, better outcomes

Vascular malformations are rare. A general center may see a handful of cases a year. Centers of excellence see hundreds — and that experience matters. The technical decisions (which agent for this malformation, which approach for that anatomy, when to repeat versus combine versus pivot to medical therapy) are made better by teams that have made them many times before.

Lifetime care, not just a procedure

These are lifetime conditions. Malformations evolve through growth spurts, hormonal changes, pregnancy, and over decades. We see our patients for the long haul — tracking outcomes, adjusting treatment as the malformation changes, integrating new options as the science advances, and helping with the transition from pediatric to adult care when relevant. Patients are not handed a procedure and sent on their way.

References

1. ISSVA Classification of Vascular Anomalies. International Society for the Study of Vascular Anomalies. Updated 2018 (with periodic updates). Available at issva.org/classification.
2. Adams DM, Trenor CC 3rd, Hammill AM, et al. Efficacy and Safety of Sirolimus in the Treatment of Complicated Vascular Anomalies. Pediatrics. 2016;137(2):e20153257.
3. Venot Q, Blanc T, Rabia SH, et al. Targeted therapy in patients with PIK3CA-related overgrowth syndrome. Nature. 2018;558(7711):540–546.
4. Dasgupta R, Patel M. Venous malformations and lymphatic malformations: state-of-the-art management. Pediatr Surg Int. 2014;30(3):309–321.

Frequently asked questions

What is a vascular or lymphatic malformation?

A vascular malformation is a tangle of abnormal blood vessels (veins, arteries, capillaries) or lymphatic channels that you are born with. It grows with you and can cause pain, swelling, bleeding, deformity, or functional problems depending on its location and type. The major categories — venous malformations (VM), lymphatic malformations (LM), arteriovenous malformations (AVM), and capillary malformations (port-wine stain) — each behave differently and are treated differently. Some patients have a syndrome that combines several types, such as Klippel-Trenaunay syndrome, CLOVES, or PROS.

Why does it matter to be treated at a center of excellence?

Vascular malformations are rare and complex. Centers of excellence offer things general hospitals usually cannot: a true multidisciplinary team that meets regularly to discuss each case (interventional radiology, vascular surgery, plastic surgery, dermatology, hematology, medical genetics, pain medicine), the full range of advanced procedures (sclerotherapy with bleomycin, doxycycline, ethanol, STS, OK-432; embolization with glue, Onyx, coils, vascular plugs; laser; cryoablation), genetic testing for the somatic mutations that drive these conditions (PIK3CA, TIE2, RASA1), access to targeted medical therapy including sirolimus and alpelisib, higher case volume, and lifetime follow-up — because these conditions need decades of management.

What is sclerotherapy?

Sclerotherapy is the mainstay of treatment for venous and lymphatic malformations. Under live ultrasound and X-ray guidance, a thin needle is placed directly into the abnormal vessels and a medication called a sclerosant is injected to scar them down. The malformation gradually shrinks and symptoms ease. The agent — bleomycin, doxycycline, ethanol, sodium tetradecyl sulfate, polidocanol, or OK-432 for certain lymphatic cysts — is chosen by the team for the specific malformation. Multiple treatment sessions are typically required.

Are these conditions cured?

Most vascular malformations are not cured in a single procedure. They are managed over a lifetime, with treatment goals that include relieving pain and swelling, controlling bleeding, restoring function, and improving quality of life and appearance. With modern multidisciplinary care, most patients see meaningful and durable improvement. New options — particularly targeted medical therapy with sirolimus and alpelisib for selected mutations — continue to expand what is possible.

What are sirolimus and alpelisib?

Sirolimus is an mTOR inhibitor that has changed the management of complex venous and lymphatic malformations. Alpelisib is a PI3K-alpha inhibitor that targets the PIK3CA mutation found in many vascular and overgrowth conditions, including PROS, KTS, and CLOVES. These medical therapies are typically used for malformations that cannot be fully controlled with procedures alone, and access to them is one of the things that distinguishes a center of excellence.

Why are patients referred to FIS for vascular malformations?

Patients are referred to Florida Interventional Specialists by primary care physicians, dermatologists, vascular surgeons, plastic surgeons, pediatricians, hematologists, and geneticists across Florida and beyond. The reasons include the multidisciplinary care model, the breadth of sclerosing and embolic agents we use, our coordination with medical genetics for somatic-mutation testing, and access to targeted medical therapy with mTOR and PI3K inhibitors when indicated.