Inferior vena cava thrombosis in a child with nephroblastoma and combined deficiency of antithrombin III and free protein S.

A 3 1/2-year-old girl developed thrombosis of the inferior caval and renal veins several weeks after complete resection of a nephroblastoma. Her mother had suffered from pulmonary embolism at the age of 18 years. Familial antithrombin III deficiency and persistently lowered free protein S levels in the proposita were found. It is assumed that the combination of these two regulatory defects of hemostasis contributed to the early occurrence of this severe thrombotic event.