Hemangiomas and Other Vascular Lesions

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Hemangiomas and Other Vascular Lesions

Description

  • Hemangiomas: Nonmalignant neoplasms consisting of vascular endothelial cells
  • Vascular malformations: Capillaries, veins, lymphatics, or arteries that underwent errors of morphogenesis (e.g., hamartomas)
  • Salmon patches: Distended dermal capillaries

Epidemiology

  • Hemangiomas:
    • 80% are single lesions.
    • 60% found on the head and neck
    • 25% found on the trunk
  • Vascular malformations:
    • Port-wine stains and lymphatic malformations occur equally in males and females.
    • Venous malformations occur within any body tissue including bone.

Incidence
Hemangiomas:
  • Increased incidence with prematurity
  • 10% increased incidence if chorionic villus sampling was performed during pregnancy.

Prevalence
Salmon patches: Found in 30–40% of all newborns

Risk Factors

Genetics

  • Hemangiomas:
    • Usually no genetic association
    • Seen with Klippel-Trénaunay syndrome, Parkes-Weber syndrome, Maffucci syndrome, diffuse neonatal hemangiomatosis, Cobb syndrome, and PHACES syndrome (posterior fossa malformations, hemangiomas, arterial anomalies, cardiac anomalies, eye anomalies, sternal or abdominal cleft), Gorham-Stout syndrome
    • May have autosomal dominant inheritance in some families
  • Vascular malformations:
    • Most often a sporadic finding
    • Seen with Sturge-Weber syndrome, Cobb syndrome, Wyburn-Mason (or Bonnet-Dechaume-Blanc) syndrome, Klippel-Trénaunay syndrome, Parkes-Weber syndrome, Osler-Weber-Rendu syndrome (or hereditary hemorrhagic telangiectasia [HHT]), Turner and Noonan syndromes (lymphatic malformations), Blue Rubber Bleb Nevus Syndrome (dominant inheritance)
  • Salmon patches: No genetic association

Pathophysiology

  • Hemangiomas: Appear in 1st few weeks of life; grow rapidly in 1st 6–12 months, followed by a static period, and then involute. Lesions are made up of proliferating endothelial cells.
  • Vascular malformations: Grow proportionally with the affected individual. Lesions are dysplastic vessels without endothelial proliferation. Port-wine stains (nevus flammeus) are capillary vascular malformations.
  • Salmon patches (nevus simplex): Grow proportionally with affected individual. Lesion consists of distended dermal vessels.

Associated Conditions

  • Spinal dysraphism
  • Rapidly involuting and noninvoluting congenital hemangioma (RICH and NICH, respectively): RICH, <3% of all hemangioma; NICH, extremely rare