Glomus Tumor

Overgrowth syndromes are rare genetic disorders defined by tissue hypertrophy that can be either localized or generalized, affecting both latitudinal and longitudinal growth. The genes involved in overgrowth syndromes are not well characterized but mostly concern the PIK3CA/AKT/mTOR pathway, a major actor of cell growth and proliferation. The mutations are not inherited but occurs during embryogenesis leading to somatic mosaicism. Owing to the variability of the clinical presentation, their exact prevalence is yet unknown. In order to answer this question, the investigators team create here the first French national registry on overgrowth syndromes.

In current practice, options for venous and lymphatic malformations remain limited. Recently an oral medication, sirolimus, has been found to benefit patients when taken once or twice a day for several months. Unfortunately there are many side effects associated with this medication, some of which can be severe including, neutropenia, oral ulcerations, and lab abnormalities. The purpose of this study is to determine if once weekly dosed sirolimus will be effective for the treatment of venous and lymphatic malformations. Additionally, the study will evaluate patient satisfaction and identify adverse effects. Participants will be on the medication for 6 months with an option to continue after this time period.