Background: The neoplastic thrombus in Wilms' tumor rarely can extend in to the inferior vena cava or to the right atrium. The neoplastic thrombus usually is diagnosed concurrently with the tumor, although in some cases the diagnosis of the thrombus may precede the diagnosis of nephroblastoma.
Methods: Among 90 children with Wilms' tumor who were treated in the authors' unit, 4 had extensive tumor thrombosis of the inferior vena cava or the right atrium. One of these patients was found with a life-threatening thrombosis of the inferior vena cava and the right atrium, which was treated surgically; in this case, the diagnosis of nephroblastoma was made postoperatively. As for the 3 remaining patients the diagnosis of neoplastic thrombosis and Wilms' tumor was made simultaneously.
Results: In the first case, the patient underwent surgical excision of the thrombus with cardiopulmonary bypass and a short period of hypothermic cardiopulmonary arrest. In the other 3 cases the thrombus resolved with chemotherapy only.
Conclusions: Surgical excision of extensive neoplastic thrombosis is suggested in the case of life-threatening thrombosis even with cardiopulmonary bypass. Chemotherapy is suggested in cases lacking clinical symptoms of thrombosis.