Hemangiomas are tumors identified by rapid endothelial cell proliferation in early infancy, followed by involution over time; all other abnormalities are malformations resulting from anomalous development of vascular plexuses. The malformations have a normal endothelial cell growth cycle that affects the veins, the capillaries, or the lymphatics, and they do not involute.
Hemangiomas are lesions that are not present at birth. They manifest within the first month of life, exhibit a rapid proliferative phase, and slowly involute to near complete resolution. Hemangiomas exhibit both a proliferating phase and an involuting phase, whereas vascular malformations are more stable and fail to regress.[1]
Hemangiomas of the oral cavity are not common pathologic entities, but, among hemangiomas, the head and the neck are common sites. Most true hemangiomas involute with time, but a certain small percentage do not, which may present with complications that require treatment (see Complications). An estimated 10-20% of true hemangiomas incompletely involute and require postadolescent ablative treatment.[2]
Hemangiomas are associated with the following syndromes:
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Rendu-Osler-Weber syndrome (autosomal dominant inheritance, multiple telangiectasias, occasional GI tract involvement, occasional CNS involvement)
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Sturge-Weber-Dimitri syndrome (noninherited and nonfamilial, port-wine stain, leptomeningeal angiomas)
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Kasabach-Merritt syndrome (thrombocytopenic purpura associated with hemangioma, consumptive coagulopathy, microangiopathic hemolysis, intralesional fibrinolysis)
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Maffucci syndrome (hemangiomas of the mucous membranes, dyschondroplasia)
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von Hippel-Lindau syndrome (genetic transmission variable, hemangiomas of the cerebellum or the retina, cysts of the viscera)
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Klippel-Trenaunay-Weber syndrome (port-wine stain, angiomatosis of the extremities)
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PHACE(S) (posterior fossa brain malformations, hemangiomas of the face [large or complex], arterial anomalies, cardiac anomalies, and eye abnormalities): The association is referred to as PHACE(S) when ventral developmental defects, such as sternal clefting or supraumbilical raphe, are present.
The term hemangioma has been commonly used to describe a large number of vasoformative tumors. Unfortunately, the nomenclature and the classification of these entities have been complex and not entirely consistent over time. The complexity and the inconsistency have led to a large number of terms and classification schemes being used, resulting in confusion in understanding the pathophysiology of these lesions and in comparing data from different periods. The nomenclature lends little insight into the natural history and the management of these lesions.
What was referred to as a hemangioma 30 years ago is not necessarily what a hemangioma would be referred to as today. The term hemangioma described many lesions that bore little relationship to each other apart from their being involved with vessels. With this concept in mind, this article discusses oral vasoformative tumors under the broad and not entirely correct term oral hemangiomas.
In 1982, Mulliken and Glowacki[1] described the classification scheme that is most accepted today. This scheme is straightforward and essentially divides the vasoformative tumors into 2 broad groups: hemangiomas and vascular malformations. The vascular malformations can be further subdivided into arterial, venous, capillary, and lymphatic malformations
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