1. A 13-year-old girl with multiple hemangiomata and thrombocytopenia is described.
2. Complications of surgical treatment included severe bleeding, septicemia and a fibrinolytic event.
3. Simultaneous platelet counts from the tumor and peripheral blood were performed and showed a significantly higher concentration of platelets in the tumor vessels.
4. With the rise in the platelet count, a decreased platelet fragility as well as a persistently abnormal prothrombin consumption could be demonstrated.
5. The possible role of the tumor in the pathogenesis of the thrombocytopenia is discussed.