FREDERIC B.ASKINMDWILLIAM H.WESTRAMD
Vascular anomalies can be broadly classified as either malformations or tumors. Whereas malformations are true structural errors of vascular morphogenesis, a tumor shows hypercellularity and endothelial multiplication. Of the vascular tumors, the most common is the hemangioma, 60% of which occur in the head and neck region. While vascular malformations are almost always present at birth, hemangiomas have a later presentation. Although both types of vascular anomalies may present with localized hematologic disturbances, such as platelet trapping and consumptive coagulopathy, a unique syndrome has been ascribed to a type of vascular tumor known as KHE. First described by Kasabach and Merritt1 in 1940, the association of a vascular tumor and thrombocytopenia in an infant had been considered a rare complication of the common capillary hemangioma. More recent studies,2- 6 however, have shown that the tumor in question is not a common hemangioma of infancy, but a vascular tumor with features that resemble Kaposi sarcoma.
Pathology Quiz Case 2—Diagnosis. Arch Otolaryngol Head Neck Surg. 2004;130(8):993-994. doi:10.1001/archotol.130.8.993