TY - CHAP M1 - Book, Section TI - Nonneoplastic Abnormalities of the Extremity Soft Tissues A1 - Wells, Robert G. Y1 - 2015 N1 - T2 - Diagnostic Imaging of Infants and Children AB - Klippel-Trenaunay syndrome (Klippel-Trenaunay-Weber syndrome; angio-osteohypertrophy syndrome) is a developmental vascular abnormality of the extremities. Classically, there is the triad of cutaneous capillary malformations, dilated superficial veins or venous malformations, and overgrowth of the limb (local gigantism). Capillary-lymphaticovenous malformations are present in the deeper soft tissues in most of these patients as well. Typically, the abnormality involves a single lower extremity (95%); arm involvement is rare. Klippel-Trenaunay syndrome apparently is due to a disturbance in embryogenesis, with persistence of primitive arteriovenous communications within the developing limb bud. Abnormalities of superficial veins in these patients range from ectasia of small veins to large venous or lymphaticovenous malformations. Potential deep venous abnormalities include aplasia, hypoplasia, aneurysmal dilation, duplications, and valvular incompetence.1–3 SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1148954151 ER -