Hemangiomas, the most common benign tumors of infancy, occur in about 5% of term infants (Chapter 642). The risk of hemangioma is 3-5 times higher in girls than boys. The risk is doubled in premature infants and 10 times higher in offspring of women who had chorionic villus sampling. Hemangiomas can be present at birth but usually arise shortly after birth and grow rapidly during the 1st yr of life, with slowing of growth in the next 5 yr and involution by 10-15 yr of age.

Lymphatic malformations, including lymphangiomas and cystic hygromas, which arise in the embryonic lymph sac, are the 2nd most common benign vascular tumors in children. About half are located in the head and neck area. Approximately 50% are present at birth, with most presenting by 2 yr of age. There is no gender predisposition. Spontaneous regression has been reported but is not typical.

Lymphatic malformations present as soft, painless masses that transilluminate if superficial. Intrathoracic lymphatic malformation can present as symptoms related to a mediastinal mass or pericardial or pleural effusion. Rapid enlargement can occur with infection or hemorrhage. Localized lesions may be surgically resected, but this can be difficult, owing to their infiltrative nature. Recurrence is common with incompletely resected lesions. Aspiration can provide temporary relief in an emergency, such as in the presence of dyspnea, but reaccumulation will occur. Treatment by injection of sclerosing agents, laser therapy, and systemic interferon therapy also has been used. The streptococcal immunotherapeutic agent OK-432 (Picibanil) is the sclerosing agent of choice, avoiding the need for surgery in most cases. Bleomycin is also an effective sclerosing agent but has a risk of pulmonary toxicity. It appears to be especially effective for the treatment of macrocystic lymphangiomas of the head and neck.