A Case of Wilms Tumor with a Tumor Thrombus in a Boy with WAGR Syndrome

Intravascular extension of Wilms tumor (WT) can occur in approximately 4-10% of patients. In general, it does not cause any clinical problems because most of these tumors are small. Although there is no standard treatment currently, preoperative chemotherapy and delayed nephrectomy is generally recommended for children with WT accompanied by tumor thrombus. We report a rare case of WT, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome in a boy who also had a huge inferior vena cava thrombus, 7 cm length. The prevalence of bilateral WT and tumor thrombus in WAGR has not been identified. The patient was successfully treated with neoadjuvant chemotherapy to decrease the size of the tumor thrombus with WT and delayed nephrectomy following chemotherapy without any invasive intervention and did not show complications.