A case of bilateral Wilms tumor and a case of Wilms tumor with cavoatrial extension, safely operated after preoperative chemotherapy without initial pathological diagnosis

Abstract

The general treatment strategy for Wilms tumor in Japan consists of initial surgery for staging and pathological diagnosis, followed by chemotherapy. However, in many cases of bilateral or advanced Wilms tumor with extension to the right atrium, initial surgical resection of the tumor is not possible. Although treatment strategies for these cases have not yet been fully established, the efficacy of preoperative chemotherapy has been reported, and pathological diagnosis prior to chemotherapy is not always necessary. In our case of bilateral renal tumor in a one-year-old girl, and in the case of renal tumor extending to the right atrium in a four-year-old boy, chemotherapy was started without pathological diagnosis, and safe tumor resection was possible. In these two cases, Wilms tumor was diagnosed after surgery. In cases of advanced Wilms tumor, whose safe surgical removal at diagnosis is not possible, preoperative chemotherapy may be considered, and pathological diagnosis prior to the initiation of chemotherapy is not always necessary.