Abstract
Vascular malformations are poorly recognized constitutional anomalies which arises during early childhood. Several classifications tried to draw a distinction across the different entities. Recent advances in molecular biology have contributed to the update of their nosology. Syndromic vascular malformations are an example: while Klippel-Trenaunay syndrome, Proteus or CLOVES syndrome share many common features, understanding of pathological mechanism and specially the role of the PIK3/AKT/mTOR pathway enables us to rethink their classification. Then, some syndromes associated with overgrowth and vascular malformation have been grouped under a single term: "PIK3CA-related overgrowth spectrum" (PROS), and this group continues to grow. This new approach suggests new treatment options. Rapamycin, a PIK3/AKT/mTOR pathway inhibitor, demonstrated its efficiency for some forms of PROS. Targeted therapies such as PIK3 or mTOR selective inhibitor are still in a developmental phase and results are encouraging. This is an example of personalized medicine with significant therapeutic benefit for some patients. However, genotype relation with therapeutic efficiency must be clarified and physicians should pay attention to possible negative effects of these drugs, especially for young patients.