A vascular anomaly is a kind of birthmark caused by a disorder of the vascular development, although it is not always present at birth. A vascular anomaly is a localized defect in blood vessels that can affect each part of the vasculature (capillaries, arteries, veins, lymphatics or a combination of these). These defects are characterized by an increased number of vessels and vessels that are both enlarged and sinuous.
Some vascular anomalies are congenital and therefore present at birth, others appear within weeks to years after birth and others are acquired by trauma or during pregnancy. Inherited vascular anomalies are also described and often present with a number of lesions that increase with patients’ age. Vascular anomalies can also be a part of a syndrome and, occasionally, they can be acquired by trauma. The estimated prevalence of vascular anomalies is 4.5%. Vascular anomalies can occur throughout the whole body (skin, bone, liver, intestines, i.e.), but in 60% of patients vascular anomalies are localized in the head and neck region.
Vascular anomalies can present in various ways. Vascular anomalies that are situated deep below the skin, appear blue and are often called cavernous. Superficial vascular anomalies appear as red-coloured stains and are associated with vascular anomalies affecting the dermis. Historically, vascular anomalies have been labeled with descriptive terms, according to the food they resembled (port wine, strawberry, cherry, salmon patch). This imprecise terminology has caused diagnostic confusion, blocked communication and even caused incorrect treatment, as it does not differentiate between various vascular anomalies.
VASCULAR TUMORS
Vascular tumors, often referred to as hemangiomas, are the most common tumors in infants, occurring in 1-2%. Prevalence is even higher (10%) in premature infants of very low birth weight. Vascular tumors are characterized by overgrowth of normal vessels, which show increased endothelial proliferation. It can be present at birth, but often appears within a couple of weeks after birth or during infancy. There are different kinds of vascular tumors, but the 4 most common types are: infantile hemangioma, congenital hemangioma, kaposiform hemangioendothelioma and pyogenic granuloma.
INFANTILE HEMANGIOMA
Infantile hemangioma is the most common vascular tumor. It is a benign tumor, which occurs in 4-5% of Caucasian infants, but rarely in dark skinned infants. It occurs in 20% of low weight premature infants and 2.2 to 4.5 times more frequently in females. IH most commonly presents in the head and neck region (60%), but also involves the trunk and extremities. One third of these lesions is present at birth as a telangiectatic stain or ecchymotic area. During the first four weeks of life, 70% to 90% appear. Lesions that are situated beneath the skin may not appear until 3 to 4 months of age, when the tumor is large enough. During the first 9 months, IH undergoes rapidly growth, which is faster than the growth of the child. This is called the proliferating phase. After 9 months, the growth of the tumor will decrease and equal the growth of the child for about 3 months.
After 12 months, the tumor will start to involute and might even disappear. Involution occurs in one-third of patient by the age of 3 years, in 50% by the age of 5 years and in 72% by the age of 7 years. Involution may result in residual telangiectasis, pallor, atrophy, textural changes and sometimes fibrofatty residuum. Since 90% of IH is small, localized and asymptomatic, treatment mainly consists of observation and awaiting until involution is complete. IH can be treated with corticosteroids, which accelerate involution: in 95% of patients, growth is stabilized and 75% of tumors decrease in size. Intralesional corticosteroids are most effective, but may require additional injections, as the effect is only temporarily. Systemic corticosteroids may cause lost of side-effects and are only used in problematic IH, which is too large to treat with intralesional injections. During the proliferating phase, the tumor is highly vascular. Patients who undergo operative treatment during this period, are at risk for blood loss.
Moreover, surgery during this phase, often leads to an inferior aesthetic outcome. However, patients may require intervention during childhood, because 50% of IH leave residual fibrofatty tissue, redundant skin, or damaged structures after involution. Waiting until involution is completed, ensures that the least amount of fibro fatty residuum and excess skin is resected, giving the smallest possible scar. Another option for treatment in the pulsed-dye laser. After involution residual telangiectasias can be treated with laser therapy.
CONGENITAL HEMAGIOMA
Congenital hemangioma can be distinguished from infantile hemangioma because it is fully developed at birth. It forms during prenatal life and has reached its maximal size at birth.