Activation of the coagulation system occurs within rather than outside cutaneous haemangiomas.

UNLABELLED: Haemangiomas are the commonest tumours of infancy. They can become even more serious if followed by consumption coagulopathy and even life-threatening in cases of Kasabach-Merritt syndrome, with thrombocytopenia and haemorrhage. Data exist concerning systemic coagulation abnormalities in children with haemangiomas but to our knowledge there are no data on local consumption coagulopathy in haemangioma per se. We examined blood coagulation and fibrinolysis parameters in blood withdrawn from haemangioma blood vessels and blood withdrawn from the systemic vein in 14 children with cutaneous haemangiomas (3M, 11F; age range 3 mo to 10y). Compared with controls, significant decreases in fibrinogen levels, FVII activity, antithrombin and plasmin inhibitor levels and increases in international normalized ratio (INR) and D-dimer levels were observed in the blood samples withdrawn directly from haemangioma blood vessels. Fibrinogen and antithrombin levels in samples withdrawn from systemic veins were reduced in relation to control values whilst INR values increased, but within normal ranges. D-dimer levels were increased in peripheral blood. The fibrinogen level was significantly lower and the INR and D-dimer levels were significantly higher in blood samples from haemangiomas compared to systemic blood. Clinical signs of systemic disseminated intravascular coagulation were not observed. CONCLUSIONS: Our results suggest a strong local activation and local consumption coagulopathy in haemangioma, along with less conspicuous but observable systemic changes in coagulation and fibrinolysis parameters, although without signs of consumptive coagulopathy. These systemic changes could be a reflection of intra-lesion coagulation activation although there is no evidence to suggest truly systemic disseminated intravascular coagulation.