ACQUIRED VON-WILLEBRAND DISEASE IN MALIGNANT PERIPHERAL NEUROECTODERMAL TUMOR (PNET)

In week 12 of the EICESS 92 protocol a 12-year-old boy with pelvic PNE T developed acquired von Willebrand disease: bleeding time was prolong ed (>15 min) and von Willebrand factor antigen (54%) and ristocetin co factor activity (50) were reduced. Platelet aggregations with thrombin and collagen and the number of major platelet glycoproteins/per plate let did not differ from the controls. After Haemate P(R) (Behring Werk e, Marburg, Germany) bleeding time normalized and surgery could be per formed without occurrence of bleeding episodes. Three weeks after surg ery bleeding time, ristocetin cofactor activity, and von Willebrand fa ctor antigen increased to normal paediatric values. Without occurrence of further bleeding episodes the patient received another 10 courses of polychemotherapy (EICESS 92). (C) 1995 Wiley-Liss, Inc.