The so-called “port wine stain” is a special form of nevus flammeus. These lesions tend to grow during childhood, thicken the skin surface, and do not fade with time. Such lesions occurring in the distribution of the trigeminal nerve are associated with the Sturge-Weber syndrome (also called encephalotrigeminal angiomatosis). This uncommon congenital disorder is associated with facial port wine nevi, ipsilateral venous angiomas in the cortical leptomeninges, mental retardation, seizures, hemiplegia, and radiologic opacities of the skull. Thus, a large facial telangiectasia in a child with mental deficiencies may indicate the presence of additional vascular malformations.
Spider telangiectasias are non-neoplastic vascular lesions. These lesions manifest as radial, often pulsatile arrays of dilated subcutaneous arteries or arterioles (the “legs” of the spider) about a central core (the spider’s “body”) that blanch with pressure. Spider telangiectasias commonly occur on the face, neck, or upper chest and most frequently are associated with hyperestrogenic states (e.g., in pregnant women or patients with cirrhosis).
Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease) is an autosomal dominant disorder caused by mutations in genes that encode components of the TGF-β signaling pathway in ECs. The telangiectasias are malformations composed of dilated capillaries and veins that are present at birth. They are widely distributed over the skin and oral mucous membranes, as well as in the respiratory, gastrointestinal, and urinary tracts. The lesions can spontaneously rupture, causing serious epistaxis (nosebleed), gastrointestinal bleeding, or hematuria.
Hemangiomas are very common tumors composed of blood-filled vessels These lesions constitute 7% of all benign tumors of infancy and childhood; most are present from birth and initially increase in size, but many eventually regress spontaneously (
Fig. 10.28 ). While hemangiomas typically are localized lesions confined to the head and neck, they occasionally may be more extensive (angiomatosis) and can arise internally. Nearly one third of these internal lesions are found in the liver. Malignant transformation is rare. Several histologic and clinical variants have been described:
Capillary hemangiomas are the most common type; these occur in the skin, subcutaneous tissues, and mucous membranes of the oral cavities and lips, as well as in the liver, spleen, and kidneys (
Fig. 10.28A). Histologically, they are composed of thin-walled capillaries with scant stroma (
Fig. 10.28B
Juvenile hemangiomas (so-called “strawberry hemangiomas”) of the newborn skin are extremely common (1 in 200 births) and can be multiple. These grow rapidly for a few months but then fade by 1 to 3 years of age, with complete regression by 7 years of age in the vast majority of cases.
Pyogenic granulomas are capillary hemangiomas that manifest as rapidly growing red pedunculated lesions on the skin, gingival, or oral mucosa. Microscopically they resemble exuberant granulation tissue. They bleed http://ebooksmedicine.net
Fig. 10.28 Hemangiomas.(A)Hemangiomaofthetongue.(B)Histologicappearanceinjuvenilecapillaryhemangioma.(C)Pyogenicgranulomaofthelip.
(D)Histologicappearanceincavernoushemangioma.(A and D, Courtesy of John Sexton, MD, Beth Israel Hospital, Boston, Massachusetts. B, Courtesy of Christopher
D.M. Fletcher, MD, Brigham and Women’s Hospital, Boston, Massachusetts. C, Courtesy of Thomas Rogers, MD, University of Texas Southwestern Medical School, Dallas,
Texas.)