What was the earliest classification system of vascular anomalies?
The oldest classification systems for vascular anomalies were based on folklore. Often the mother was indicted for somehow imprinting her unborn child because she had seen something, eaten too little, eaten too much, frightened by something or other in some way was responsible. That doctrine was called “maternal impressions”. In the 19th century, vascular tissues were examined through a microscope, particularly by Virchow, the father of cellular pathology. He proposed the first histological classification of vascular anomalies, calling them all “angiomas,” that term eventually became “hemangiomas.” Throughout the late 19th century and most of the 20th century, every vascular lesion in the skin, whether it was blue, purple, or pink or some combination, was called “hemangioma.” Even today, many colleagues cannot stop calling vascular malformations hemangiomas.” Some of the specialties have been slower to understand the differences between these vascular anomalies. There was a period where embryology was a burgeoning science early in the 20th century. Embryology tried to explain the various vascular anomalies but that approach was only somewhat useful, but not clinically helpful. Recently we’ve been studying the molecular basis of development of vasculature. In the future, there will be molecular classifications. We have already found genes for certain vascular anomalies, malformations in particular. There is excitement about the genes that are involved in hemangiomas and other tumors.
John Mulliken, MD
How are vascular anomalies classified?
MBS: Vascular anomalies actually were classified by one of the physicians who works in our group, Dr. John Mulliken. He classified them into vascular tumors and vascular malformations. The most common vascular tumor is hemangioma, but there are other very rare vascular tumors, such as kaposiform hemangioendothelioma. Vascular malformations are abnormalities that develop during fetal life in any of the vessels within the body, be it capillaries, veins, lymphatic vessels, arteries or any combination of these vessels.
ES: The majority of the vascular tumors we follow are benign, or non-cancerous, but they can certainly cause problems and symptoms throughout a person’s life. Parents and patients are understandably concerned when they hear the word “tumor”, so we work to provide education on the type of tumor a patient has and what that may mean in terms of risks.
Erin Spera, MS, CPNP and Mary Beth Sylvia, MS, FNP-BC
The simple (though revolutionary) way of classifying these disorders was the one proposed by professor John Mulliken in 1982; it divides anomalies simply into vascular tumors and vascular malformations. Vascular tumors are the ones that grow rapidly such as infantile hemangiomas, the prototype of this group. These vascular tumors enlarge during the first year of life and then shrink over time; they are more likely not to leave anything leftover. Other tumors can be a little bit more aggressive, or even malignant and lethal.
On the other side, you have the vascular malformations. These are disorganized tissue made mainly of blood vessels with 3 different lineages of vessels; lymphatic vessels (lymphatic malformation), veins (venous malformations), and capillaries (capillary malformations). Also, there are combinations as seen in arteriovenous malformations. These malformations are like having an excessive, unneeded overgrowth of an organ, it grows with you.
Ahmad Alomari, MD, MSc, FSIR