Acquired Von Willebrand disease in children with a Wilms' tumor.

The association between acquired von Willebrand disease and Wilms' tumor has been reported in eight cases: four cases reports and one prospective study of Coppes et al. (J. Clin Oncol 10:422-427, 1992) who found this in four out of 50 patients. We retrospectively studied 73 children who were diagnosed with a Wilms' tumor between 1970 and 1993. All patients were treated according to the running international SIOP protocol. According to our local diagnostic workup protocol, blood samples for screening coagulation tests were obtained at diagnosis and during preoperative chemotherapy. Since 1984, factor VIII analysis was added. In four patients, no coagulation screen was done. Bleeding time and screening tests apart from APTT were normal in all 69 children tested before or within 2 days after starting therapy. In 47 out of 73 patients, an APTT was performed before starting therapy. In 19 patients (40%), it was prolonged (>33 sec). In 8 of them (17%), the prolongation was severe (> or = 40 sec). In 11 out of the 19 patients, factor VIIIc, factor VIIIag, and factor VIII RcoF determinations were done. In two children, all three factors were decreased suggestive for von Willebrand disease. One of the 19 patients with a prolonged APTT had hematuria. The others had no increased bleeding tendency or signs of bleeding in the tumor. In all patients, the prolonged APTT normalised during preoperative chemotherapy within 6 weeks. Frequent blood samples were obtained of the two children with acquired von Willebrand disease and showed normalisation of the coagulation disorder after 1 and 2 weeks, respectively. No specific therapy to correct the coagulation abnormalities was given to any patient.