Kaposiform Lymphangiomatosis (KLA) Multifocal lymphatic anomaly that often involves thorax, bones, viscera Progressive involvement, severe morbidity, high mortality rate Coagulopathy: severe hypofibrinogenemia, thrombocytopenia and high rate of bleeding complications Effusions Hemorrhage Respiratory and multiorgan failure Focal areas of spindled lymphatic endothelial cells with abnormal lymphatics; similar to KHE but the spindle cell component is more dispersed and arranged in poorly defined clusters or anastomosing strands/sheets Mutation: NRAS