Right Atrial Tumor Thrombus in Pediatric Nephroblastoma: A Case Report

Nephroblastoma is the most common malignant renal tumor in children. Tumor thrombus extending into the vena cava and right atrium increases the complexity of surgical treatment. We report the case of a nine-year-old girl with nephroblastoma complicated by a tumor thrombus extending into the inferior vena cava and right atrium. She received four weeks of preoperative chemotherapy, which resulted in a reduction of both the primary tumor and the thrombus. The tumor thrombus was classified as T3c according to the 2010 AJCC staging system and as Level IV according to the Mayo Clinic classification. The surgical strategy was planned according to the extent of tumor thrombus as defined by these two classification systems. The patient then underwent en bloc resection of the tumor via a combined thoracoabdominal approach, consisting of an extended right nephrectomy via a subcostal incision with thrombectomy of the right atrium performed under extracorporeal circulation. Postoperatively, she received radiotherapy and additional chemotherapy based on risk stratification. At the three-year follow-up, she remains in complete remission with no evidence of recurrence. The presence of a tumor thrombus does not necessarily worsen prognosis if complete surgical resection is achieved. Preoperative chemotherapy can shrink the tumor and thrombus, facilitating resection and preventing complications. Simultaneous thoracoabdominal surgery under extracorporeal circulation enables en bloc resection of the primary tumor and thrombus. With multimodal treatment, children with Wilms tumor and tumor thrombus can achieve long-term survival.