More than one-third of infants are born with a vascular birthmark.¹ Although most of these lesions are benign and uncomplicated, a minority require treatment and inpatient care. The pediatric hospitalist should be able to recognize major types of vascular anomalies and identify lesions requiring referral to, or immediate medical care in collaboration with, vascular anomaly specialists in fields such as dermatology, surgery, hematology/oncology, pathology, orthopedics, and radiology.

In 1996, vascular anomalies were reclassified into two main categories: malformations and tumors (Table 60-1).^2,3 Vascular malformations are comprised of structurally abnormal vessels with normal endothelial turnover, and are subcategorized based on their endothelial components (e.g. capillary, venous, lymphatic, and/or arteriovenous) and flow characteristics (i.e. slow flow vs. fast flow). These anomalies may be stable or progressive; they generally do not regress. In contrast, vascular tumors arise by endothelial hyperplasia, and may be benign, borderline, or sometimes malignant.

Capillary malformations (also known as “port-wine stains”) are slow-flow lesions that may be focal, regional, or diffuse. Clinically, capillary malformations are pale pink to deep red blanching patches that are present at birth and generally permanent. Over time, some lesions, particularly those on the face, may darken, thicken, and become more nodular. Regional and diffuse capillary malformations may be associated with soft tissue or bony overgrowth or undergrowth.

Fading macular stains of infancy (also referred to as “angel’s kisses,” “stork bites,” or “salmon patches”) are a subset of capillary malformations located on the glabella, eyelids, forehead, and posterior neck. Unlike the typical vascular malformation, these lesions may fade or disappear entirely after 1 to 2 years of life; however, some lesions, particularly those on the nape of the neck, may persist.

Venous malformations (sometimes called “venous angioma” or “cavernous hemangioma”) are slow-flow vascular malformations comprised of irregular, dilated venous channels. Lesions are present at birth, though they may not be clinically evident. Typically, venous malformations present as soft, compressible bluish papules, nodules, or masses that tend to become more prominent with age, dependency, and physical activity (Figure 60-1). Lesions may be confined to the skin and subcutaneous tissue, or may involve deeper structures such as muscle, bone, and viscera. Diminished or stagnant blood flow within ectatic venous channels may lead to production of thrombin and conversion of fibrinogen to fibrin, resulting in chronic localized intravascular coagulation with episodes of localized thrombosis or bleeding.⁴

Lymphatic malformations consist of irregular, ectatic lymphatic channels, and are classified as macrocystic or microcystic based on the size of the cystic spaces present. Microcystic lesions (formerly called “lymphagioma circumscriptum”) may form clear or hemorrhagic thin-walled vesicles or hyperkeratotic papules at the surface of the skin. Macrocystic lymphatic malformations (formerly referred to as “cystic hygroma”) are usually visible at birth, commonly occur on the neck and axilla, and form large, subcutaneous, compressible masses.

Arteriovenous malformations (AVMs) are fast-flow lesions consisting of structurally abnormal arterial and venous vessels directly connected without an intervening capillary bed. Although present at birth, many AVMs may not be apparent until childhood. Early AVMs typically present as pink to red patches on the head or neck and may mimic a capillary malformation or infantile hemangioma. Lesions may have increased warmth, or a palpable thrill. Over time, AVMs may expand, darken, and invade deeper structures, particularly after pregnancy, puberty, trauma, or radiologic or surgical treatment. Late-stage lesions may cause deep destruction with necrosis, ulceration, severe pain, and bleeding. Large AVMs may induce high-output cardiac failure due to increased blood flow.

Combined malformations are vascular malformations that include more than one anomalous vessel type, and are frequently associated with skeletal and soft tissue hypertrophy or hypotrophy. Klippel-Trenaunay syndrome is a slow-flow combined anomaly comprised of abnormal capillary, lymphatic, and venous elements. In contrast, Parkes Weber syndrome is fast-flow combined anomaly characterized by capillary staining with arteriovenous fistulas. Both Klippel-Trenaunay and Parkes Weber syndromes may present with the triad of a capillary stain, venous varicosities, and soft tissue and bony hypertrophy of the lower limb. CLOVES syndrome consists of congenital lipomatous overgrowth (typically, a truncal lipomatous mass), vascular malformations (frequently capillary malformations, lymphatic malformations, or high-flow lesions), epidermal nevi, and scoliosis, skeletal, and spinal anomalies.⁵

DIAGNOSTIC EVALUATION

The assessment and management of a vascular malformation depends on the type, location, and extent of the lesion. Typically, venous malformations and lymphatic malformations can be diagnosed clinically or with the aid of magnetic resonance imaging (MRI). AVMs can usually be diagnosed by ultrasonography or MRI.

Infants with a capillary malformation in the distribution of the ophthalmic (V1) branch of the trigeminal nerve should be evaluated for Sturge-Weber syndrome, characterized by a facial capillary malformation, leptomeningeal angiomatosis, and vascular malformations of the choroid of the eye. Clinical manifestations may include seizures, developmental delay, and glaucoma. Further workup should include MRI with and without contrast to assess for leptomeningeal angiomatosis, and an ophthalmologic examination to evaluate for choroidal vascular malformations and glaucoma.

Like other congenital midline lesions such as lipomas, tails, or dermal sinuses, capillary malformations in the midline lumbosacral region may warrant further investigation for occult spinal dysraphism. Paraspinal lumbosacral capillary malformations that appear in combination with a second congenital midline skin lesion present a particularly high risk of spinal anomalies.⁶ Evaluation should include ultrasonography for infants less than 4 months of age, or MRI for children older than 4 months of age.

Patients with regional capillary malformations of the lower limb, Parkes Weber syndrome, or Klippel-Trenaunay syndrome may have overgrowth or undergrowth of the affected leg. Such patients should be evaluated by an orthopedic surgeon for limb length discrepancy around the age of 1 year.

Multiple cutaneous venous malformations, particularly on the palms and soles, may be associated with gastrointestinal tract venous malformations in blue rubber bleb nevus syndrome. Clinical manifestations may include anemia from chronic occult gastrointestinal bleeding, abdominal pain, rectal bleeding, melena, or hematemesis. Further work up should include a complete blood count to assess for anemia, as well as imaging studies (such as MRI or computed tomographic scan) to evaluate for gastrointestinal involvement.

Multifocal capillary malformations may be associated with fast flow vascular lesions in capillary malformation-arteriovenous malformation (CM-AVM), which results from autosomal dominant mutations in RASA1.⁷ CM-AVM typically presents with multiple pink-red, small, round-to-oval macules, some of which have a pale halo. Larger lesions are sometimes fast-flow by Doppler exam. Although patients with CM-AVM generally have a benign clinical course, CM-AVMs have rarely been associated with cerebral AVM.⁸ As a result, further workup with MR/magnetic resonance angiogram (MRA) of the brain may be considered.

MANAGEMENT

Capillary malformations may be treated with pulsed dye laser, which selectively targets oxyhemoglobin.

The goal of treatment of venous malformations is to prevent disfigurement, functional impairment, pain, and swelling. Conservative management may include compression therapy only, which can limit swelling, alleviate pain, and reduce localized intravascular coagulation.⁹ Sclerotherapy and surgical excision, alone or in combination, can be considered for more symptomatic lesions. Low molecular weight heparin may improve pain resulting from localized thrombus formation.⁴

Treatment of lymphatic malformations may be considered to preserve function, limit deformity, and minimize pain and swelling. The primary therapeutic interventions for lymphatic malformations, like venous malformations, are sclerotherapy and surgical excision. Recently, marked regression of lymphatic malformations has been reported after treatment with oral sildenafil.¹⁰ Microcystic lymphatic malformations tend to be less responsive to sclerotherapy, and are sometimes more successfully treated with pulsed dye laser (when hemorrhagic), carbon dioxide laser, and Nd-YAG laser.^11-13

Management of AVMs is challenging. Treatment generally consists of embolization, surgical resection, or a combination of the two; however, rates of recurrence are high, ranging between 85% and 98%.¹⁴ The risk of recurrence has been found to be lower following treatment of earlier-stage lesions.¹⁴

ADMISSION CRITERIA

Certain clinical scenarios require immediate attention and possible inpatient admission for complications of vascular malformations.

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  A patient with Sturge-Weber syndrome and extensive leptomeningeal angiomatosis may require hospitalization for management of seizures or following surgical procedures, such as goniotomy or trabeculotomy, for treatment of glaucoma.

  
  
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  Extensive venous malformations may cause localized intravascular coagulopathy, with risk for deep venous thrombosis and pulmonary embolus, particularly perioperatively; inpatient management is recommended.

  
  
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  Patients with blue rubber bleb nevus syndrome may require inpatient stabilization or possible surgical intervention for gastrointestinal bleeding, intussusception, volvulus, or infarction.

  
  
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  Patients with lymphatic malformations may be hospitalized for bacterial superinfection (which may present as sudden enlargement of the lesion), or less commonly, chylous pleural effusions and chylous ascites leading to respiratory distress.

  
  
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  Large AVMs may result in ulceration, pain, bleeding, obstruction of vital structures, and rarely, high-output cardiac failure, which may warrant inpatient admission for endovascular embolization, surgical resection, or management of heart failure.

  
  
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  Complications of combined vascular malformations of an extremity (such as ulceration, pain, bleeding, recurrent cellulitis, deep venous thrombosis, and pulmonary embolism), may require immediate inpatient care. In addition, patients with combined vascular malformation involving the lower limb (such as Klippel-Trenaunay or Parkes Weber syndromes) may be hospitalized following epiphysiodesis for leg length discrepancy.

  
  
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  Patients with CLOVES syndrome may be hospitalized following spinal fusion for treatment of scoliosis.

  
  
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  Patients with combined vascular anomalies (such as Klippel-Trenaunay, Parkes Weber, or CLOVES syndromes) may be admitted for surgical debulking.