Chronic localized intravascular coagulation complicating multifocal venous malformations.

We present two female children aged 7 years with extensive multifocal venous malformations complicated by chronic localized intravascular coagulation. In both cases ultrasonography and magnetic resonance imaging revealed extensive venous malformations involving the skin, mucous membranes and pharynx, which were not apparent on clinical examination. Haematological investigations demonstrated persistent elevation of the D-dimer, consistent with chronic localized intravascular coagulation. The course of one patient was complicated by the development of multiple painful thromboses at distant sites following percutaneous sclerotherapy. Persistent elevation of the D-dimer occurring in association with large venous and veno-lymphatic malformations has been termed chronic localized intravascular coagulation, and is thought to occur due to thrombosis at sites of stagnant blood flow within venous malformations. It is of clinical concern due to the potential for transformation into serious thrombohaemorrhagic coagulation disorders, including disseminated intravascular coagulation. While previously described in association with large segmental venous malformations, these cases demonstrate the occurrence of chronic localized intravascular coagulation as a complication of disseminated multifocal venous malformations.