A venolymphatic malformation (VLM) is a rare type of venous malformation that involves veins and lymph vessels. They can cause areas of fluid buildup as well as swelling, pain, infection and deformity.
What You Need to Know
- Vascular malformations that involve lymphatic vessels and veins are called venolymphatic malformations (VLMs).
- Complications of VLMs may include deformity of the arms or legs, airway problems and infections.
- VLMs are treated with compression garments, sclerotherapy or surgery.
- The female-to-male ratio of people born with venolymphatic malformations is 9:1.
What is a VLM?
A venolymphatic malformation ― a type of vascular malformation ― is an abnormally formed area of blood and lymph vessels. Forming early in the developing fetus, VLMs can involve the veins, arteries, capillaries and lymph vessels.
Although rare, VLMs are much more common in females; the ratio of females to males with these disorders is 9:1.
They commonly show up as a mass, most often in the head and neck and involving the mouth, lip, tongue or facial muscles. In addition to affecting one’s appearance, venolymphatic malformations can cause health problems if they grow in the airway. Very rarely, they can grow in the leg, intestine, heart or in the space between the lungs.
Venolymphatic malformations are categorized as low-flow vascular malformations. This means that blood and lymph flow through them relatively slowly, compared with vascular malformations that involve arteries.
A venolymphatic malformation under the voice box (larynx) in the throat can endanger breathing if it compresses the trachea. This is a risk in VLMs that affect babies because their tracheas are more flexible than those of adults. Swelling and airway compromise may require tracheostomy.
VLMs in the limbs may distort the child’s appearance. If the VLM becomes large enough to affect function of an arm or leg, treatment may be called for.
Venolymphatic Malformation: Orbit
Treating venolymphatic malformations involving the eye can be challenging. VLMs arising in the orbit (the bones surrounding the eyeball) can develop and expand quickly, causing optic nerve compression, disk swelling and vision problems. Using ultrasound, doctors can drain cysts filled with blood or lymph to relieve pressure. It is difficult to surgically remove these growths without risking damage to the eye.
What causes VLMs?
VLMs are caused by gene mutations. Specifically, there is a link between a mutation in the tyrosine kinase (TEK) chromosome on the ninth gene and areas of veins and lymph vessels growing together abnormally. This happens at embryo stage when the body’s blood and lymph vessels are forming.
When veins and lymph vessels grow together in an abnormal way, they can cause a buildup of blood and lymph that cannot drain. VLMs cause symptoms such as:
- A large mass, especially in the head, face or neck, but can also involve an arm or leg
- Facial asymmetry (the halves of the face look markedly different) or facial features that are distorted or displaced. An enlarging mass in the soft tissues of the face can push one eye to a lower position than the other or cause one cheek or side of a lip to be much larger than the other.
- Enlarged tongue (macroglossia) that may protrude from the mouth
- A large, benign, sac-like growth on the neck or upper back of a fetus or newborn (cystic hygroma)
- Very dark red, raised marks on the skin (lymphangioma)
- Abnormal bone growth, including the jaws and teeth
- Blood clots
- Recurring infections because fluids in the malformation cannot drain properly
In some cases, venolymphatic malformations are not obvious in a newborn. Most are diagnosed in people in their 30s. They can become symptomatic due to hormone changes such as:
- Taking birth control pills
Systemic (all over the body) conditions such as infection, trauma or surgery can make a venolymphatic malformation grow or start to cause symptoms.
As a first step in diagnosing a venolymphatic malformation, the doctor will inspect it as part of an overall physical examination. Diagnosis can rule out other problems such as cysts, hemangiomas or tumors.
If a VLM is suspected, the following tests may be recommended:
- MRI is the most useful test in evaluating a malformation of veins and lymph vessels. Using this test, the doctor can see the full size and shape of the malformation, which can help plan surgery if this will be part of the treatment. A special kind of MRI that examines veins, called magnetic resonance venography, or MRV, may be used.
- Vascular studies using ultrasound can also detect a venolymphatic malformation.
- An X-ray can detect hardened blood clots (vein stones, called phleboliths) that can occur with venolymphatic malformations.
- Computed tomography (CT) is seldom used, except when the doctor suspects that the malformation has affected bone.
Vascular and lymphatic malformations can get larger due to lymph flow, bleeding within the lesion and inflammation. Treatment may be necessary for a VLM that is large, disfiguring, painful or repeatedly infected.
Treatment method depends on the size and location of the malformation.
Like other venous malformations, VLMs can be treated with a range of approaches, including:
- Observation: If the venolymphatic malformation is not causing symptoms, your doctor may periodically examine it to see if it grows or changes.
- Local pressure: Special compression garments may be recommended for a person with venolymphatic malformation in the arm or leg.
- Antibiotics: Fluids pooling in a venolymphatic malformation raise the risk of repeated infection, especially if bacteria or viruses are circulating in the blood stream. Antibiotics may be prescribed to bring a bacterial infection under control.
- Laser therapy: A dermatologist may use this technique to treat small malformations on or close to the skin surface.
- Sclerotherapy: Treatment to block or seal off vessels that are draining into a VLM is one approach. Doctors use image-guided needles to inject medicine into the vessels that creates scar tissue so blood and lymph cannot get through.
- Surgery: Removing the malformation surgically may be possible if doctors can use imaging to determine the shape and size of the malformation, ensure bleeding can be controlled, and confirm that other structures (eyes, nerves) are not at risk for injury.
Living with a Venolymphatic Malformation
A venolymphatic malformation may grow with hormone changes. Some may recur. You may have to return to your doctor throughout your lifetime to have malformations examined and treated if they cause symptoms.