Deep vein thrombosis in the setting of Klippel-Trenaunay syndrome and sirolimus treatment

Klippel-Trenaunay syndrome (KTS) is a congenital vascular disorder characterized by the triad of cutaneous capillary malformation, lymphatic and venous anomalies, and soft tissue and bone overgrowth. Sirolimus is a mechanistic target of rapamycin inhibitor used as an immunosuppressive drug. It has also been used to improve and treat vascular malformations that can predispose to intravascular coagulopathy. We have described the case of a patient with KTS receiving a therapeutic anticoagulation dose, for whom sirolimus was initiated, and who had presented with an extensive venous thromboembolism. Correlations between the use of sirolimus in patients with KTS are limited, and cautious use and monitoring could be necessary.