Trametinib normalizes angiopoietin-2 levels and successfully treats kaposiform lymphangiomatosis.

Kaposiform lymphangiomatosis (KLA) is a complex lymphatic anomaly with high morbidity and mortality. Angiopoietin-2 (Ang-2) levels are elevated in the blood of patients with KLA and can be used to aid in diagnosis and monitor treatment response. We report a male child with hydrocele, a left-sided pleural effusion, splenomegaly, and consumptive coagulopathy who was eventually diagnosed with KLA. Sirolimus did not provide a lasting therapeutic response, so treatment was switched to trametinib. The patient had an excellent response to trametinib with resolution of the pleural effusion, splenomegaly, and coagulopathy; normalization of Ang-2 levels; and significant improvement in clinical symptoms.