Distinguishing Features of Vascular Tumors (Hemangiomas) and Vascular Malformations
| Tumors | Malformations | |
|---|---|---|
| Presence at birth | Usually postnatal, 30% nascent, rarely full grown | 100% (presumably), not always obvious |
| Male:female ratio | 1:3-1:5 | 1:1 |
| Incidence | 1-12.6% at birth; 10-12% at 1 year | 0.3-0.5% port-wine stain |
| Natural history | Phases: proliferating, involuting, and involuted | Proportionate growth; can expand |
| Cellular | Endothelial hyperplasia | Normal endothelial turnover |
| Skeletal changes | Occasional mass effect on adjacent bone; rare hypertrophy | Slow-flow: distortion, hypertrophy, or hyperplasia Fast-flow: destruction, distortion, or hypertrophy |
Source: Reproduced with permission from Virnelli-Grevelink S, Mulliken JB. Vascular anomalies and tumors of skin and subcutaneous tissues. In: Freedberg IM, Eisen AZ, Wolff K, et al, eds. Fitzpatrick's Dermatology in General Medicine. 6th ed. New York, NY: McGraw-Hill; 2003:1002-1019.