ANGPT1 and Thrombocytopenia: • KLA patients have more serious symptoms (thrombocytopenia and hemorrhagic pleural effusion) and a more unfavorable prognosis than those with GLA.• Both diseases show dilated, malformed lymphatic channels, but KLA partially shows foci of patternless clusters of spindle cells.• Ang-2, Ang-2/Ang-1: KLA >controls, GLA