Activated lymphatic and capillary vessels in KHE with KMP. (A) Rapid expansion and infiltration of KHE in response to inflammation, infection, or injury. (B) D2-40⁺ histologic stain ×20 view reveals abnormal lymphatic vessels. (C) CD61⁺ histologic stain ×40 view reveals platelet trapping within abnormal capillary vessels. (D) Upregulated and overexpressed signaling from activated abnormal lymphatic endothelium results in increased vessel immune transport, protein trafficking, and lymphangiogenesis. (E) Turbulent blood flow within abnormal capillary vessels results in activated endothelium, consumptive platelet trapping, and hyperfibrinolysis causing KMP. ANGT2, angiopoietin-2; TF, tissue factor; vWF, von Willebrand factor.