Capillary hemangiomas are benign, highly proliferative lesions involving aberrant localized growth of capillary endothelium. They are the most common tumor of infancy, occurring in up to 10% of all births (Mulliken and Young, 1988). Hemangiomas tend to appear shortly after birth and show rapid neonatal growth for up to 12 months characterized by endothelial hypercellularity and increased numbers of mast cells. This phase is followed by slow involution at a rate of about 10% per year and replacement by fibrofatty stroma. Hemangiomas are classified as distinct from vascular malformations (see, e.g., CMC1, 163000; 108010; and CCM, 116860), in that the latter are present from birth, tend to grow with the individual, do not regress, and show normal rates of endothelial cell turnover (Spring and Bentz, 2005; Legiehn and Heran, 2006). Legiehn and Heran (2006) noted that the term 'hemangioma' in adults is considered inaccurate and should be discarded.
Most hemangiomas occur sporadically, but some families with autosomal dominant inheritance have been reported (Walter et al., 1999). [from
OMIM]