Klippel-Trenaunay-Weber syndrome

Klippel-Trenaunay-Weber syndrome A rare congenital malformation syndrome of the vascular system characterized by enlargement of a single limb (asymmetric limb hypertrophy), varicose veins, abnormal connections in the vasular system (arteriovenous malformations), and abnormal nests of blood vessels that proliferate inappropriately and excessively (hemangiomata, or port-wine stains), and pigmented moles on the skin (nevi). Abbreviated KTW syndrome. Some sources subclassify those patients with arteriovenous malformations as having Parkes-Weber syndrome and those with the original findings of port-wine stain, varicose veins, and bony and soft tissue hypertrophy involving an extremity as having Klippel-Trenaunay syndrome. The cause of KTW syndrome is unknown.