A 56-year-old woman has had recurrent nosebleeds starting in childhood and has visible telangiectasias on her lips and tongue (Figure 211-1). In early adulthood, she was diagnosed with hereditary hemorrhagic telangiectasias (HHTs) (Osler-Weber-Rendu syndrome) and was found to have an arteriovenous malformation (AVM) in the lung requiring surgical resection. She has led a normal productive life and has two children who have not inherited this condition. Her mother had recurrent epistaxis, but never had an AVM.
Hereditary hemorrhagic telangiectasias (Osler-Weber-Rendu syndrome) in a 56-year-old woman with recurrent nosebleeds and an arteriovenous malformation in the lung. (Reproduced with permission from Richard P. Usatine, MD.)
Hereditary and congenital vascular lesions range from the very common and benign stork bite (a variation of nevus flammeus) to rare but serious neurocutaneous syndromes. Childhood hemangiomas are covered separately in Chapter 115, Childhood Hemangiomas.
Hereditary hemorrhagic telangiectasia (HHT) is an autosomal-dominant vascular disorder that affects one in several thousands of people (see Figure 211-1). Certain populations in Europe and the United States have a higher prevalence of this disease.1
Nevus flammeus, or port-wine stains, are congenital vascular malformations that occur in 0.1% to 0.3% of infants as developmental anomalies. They persist into adulthood (Figure 211-2).2 They may be associated with rare syndromes such as Klippel-Trenaunay and Sturge-Weber syndromes (Figure 211-3).
Maffucci syndrome is a rare, nonhereditary condition characterized by hemangiomas and enchondromas involving the hands, feet, and long bones (Figure 211-4).3
Large nevus flammeus or port-wine stain over the trunk of a 55-year-old man since birth. (Reproduced with permission from Casey Pollard, MD.)
Port-wine stain, since birth, on the face of a man. Its distribution puts this patient at risk of Sturge-Weber syndrome. (Reproduced with permission from Richard P. Usatine, MD.)
Hereditary hemangiomatosis, also called Maffucci syndrome. Note the cobblestone deformity of the foot. (Reproduced with permission from Jeff Shellenberger, MD.)
ETIOLOGY AND PATHOPHYSIOLOGY
HHT is associated with mutations in two genes: endoglin on chromosome 9 (HHT type 1) and activin receptor-like kinase-1 on chromosome 12 (HHT type 2). These genes are involved in vascular development and repair. With the mutations, arterioles become dilated and connect directly with venules without a capillary in between. Although manifestations are not present at birth, telangiectasias later develop on the skin, mucous membranes, and GI tract. In addition, AVMs ...