Evaluation and management of the lateral marginal vein in Klippel-Trénaunay and other PIK3CA-related overgrowth syndromes

Mechanochemical and surgical ablation of an anomalous upper extremity marginal vein in CLOVES syndrome identifies PIK3CA as the culprit gene mutation

“…Moreover, the immediate subdermal location of the anomalous marginal veins and their characteristic lack of fascial encasement can render these entities more susceptible to symptomatic thrombophlebitis after embolization. 1,[9][10][11] CONCLUSIONS This is the first ever report of exome sequencing performed on an anomalous extremity marginal vein. The p.C420R PIK3CA mutation is one of five recurrent oncogenic variants, found in up to 80% of the vascular malformations in KTS and CLOVES, 12 and enhances binding to membrane phospholipids, triggering constitutive kinase activity.…”

“…10,11 We therefore continue to recommend transcatheter embolization as first-line treatment. 1 As seen in this particular case, prior embolization and thrombosis of the marginal vein minimize operative blood loss should surgical excision be needed in the future.…”

“…Complete thrombosis of the anomalous vein with an initial thrombophlebitic response is the desired outcome. 1,9 Immediate postoperative symptoms and the severity thereof are variable, depending on the volume and location of the embolized vein. In general, larger, more voluminous venous trunks tend to have a more profound thrombophlebitic response after embolization, which warrants close postoperative surveillance.…”

“…Treatment of these incompetent, anomalous venous structures was warranted to address symptoms, to prevent hematologic derangements, and to minimize risk of thromboembolic events. 1 The patient consented to publication of this report. Completion venography and duplex ultrasound showed no residual flow through the lateral marginal vein and the embolized venous tributaries (Fig 2, E).…”

“…Anomalous marginal veins of the trunk and extremities—found in association with Klippel-Trénaunay syndrome (KTS) and congenital lipomatous overgrowth, vascular malformations, epidermal nevus, and skeletal deformities (CLOVES) syndrome—are a major source of venous hypertension-related morbidity and potentially lethal thromboembolic events. 1 , 2 These congenitally incompetent anomalous veins have been referred to as persistent embryonic veins, suggesting that they are noninvoluting embryonic remnants. 3 , 4 Our staged, multimodal therapeutic approach incorporating paired exome sequencing to identify a somatic mutation provides further insight into the pathophysiologic mechanism of these anomalous entities and questions the validity of traditionally applied nomenclature.…”