Pulmonary thromboembolism associated with Klippel-Trenaunay syndrome

Klippel-Trenaunay syndrome (KTS) is a rare congenital anomaly characterized by unilateral limb overgrowth, venous varicosities, and capillary malformations (port wine stains) of the affected limb or limbs. Large venous malformations such as those observed in KTS are rare, and many physicians are unfamiliar with the potential complications, which include hypercoagulability, thrombosis, and pulmonary embolism (PE). As a result, patients may suffer from delayed diagnosis of a potentially life-threatening thromboembolic event. We present 2 cases of children with KTS complicated by PE, and we review the English-language literature regarding pathophysiologic features, interventions, and outcomes of PE in the setting of KTS among both pediatric and adult patients, with emphasis on issues relevant to pediatricians.