Klippel-Trenaunay-Weber Syndrome (cont.)

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What is a port-wine stain?

A port-wine stain is a certain type of hemangioma. This capillary hemangioma has a recognizable appearance. It is usually a deep violet ("port-wine") colored lesion with fairly linear borders. These are most often found on the affected hypertrophied limb. They are generally flat or only slightly raised compared to the surrounding unaffected skin surface. The actual depth of the lesion is unpredictable and less commonly may even affect muscle and bone.

In addition to the port-wine stain, individuals with Klippel-Trènaunay-Weber also develop varicose veins. These often can be seen at birth as a large superficial vein extending from the lower leg all the way up to the buttocks. This vein has been referred to as the "Klippel-Trènaunay" vein and may not be obvious until later in childhood.

Occasionally affected individuals develop an arteriovenous fistula (abnormal connection between an artery and a vein). This is known as the Parkes-Weber variant of KTW. These patients usually have numerous fistulae that can result in heart failure if untreated.

What is asymmetrical limb hypertrophy?

Asymmetric limb hypertrophy is enlargement of one limb compared to the opposite side. For example, an individual with Klippel-Trènaunay-Weber syndrome may have a left leg or arm that is larger than his/her right leg or arm. This asymmetry is found in other inherited syndromes as well. Most commonly in individuals with Klippel-Trènaunay-Weber, the leg is involved more frequently than an arm; however, on occasion there is enlargement of two limbs, a buttock, or part of the trunk of the body.

Are there other abnormalities in Klippel-Trènaunay-Weber syndrome?

Although the triad of "port-wine stain, varicosities, and asymmetric limb hypertrophy," is the consistent clinical centerpiece of Klippel-Trènaunay-Weber, there are often other less frequent abnormalities found in those affected by the syndrome. These may include other limb or digit abnormalities such as:

  • atrophy (a limb that is underdeveloped),
  • fingers and toes that are disproportionately large or small,
  • digits that are webbed (syndactyly),
  • too many digits (polydactyly), or
  • too few digits (oligodactyly).

In addition to limb abnormalities, there are some other common features, including:

  • asymmetrical facial hypertrophy (one side of the face may be smaller than the other),
  • macrocephaly (a large head), or
  • microcephaly (a small head).

Eye problems may include glaucoma and cataracts. Any of the vascular anomalies can affect the internal organs including the intestinal and urinary tract systems. These may be at risk for spontaneous bleeding, and it is important to evaluate any individual with evidence of superficial abdominal lesions. Additionally, there is an increased risk of abnormal blood clots forming, which can move to the lungs, causing a pulmonary embolism.

Medically Reviewed by a Doctor on 1/14/2014

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