[Application of the pathological classification of "CCCG-WT-2016" (2019 revision) for treatment of Wilms tumors].

Objective: To describe our experiences in application of the 2019 revision of "CCCG-WT-2016" for the diagnosis of Wilms tumors. Methods: Ninety-one cases of Wilms tumor diagnosed at Shanghai Children's Medical Center from January 2015 to December 2018 were collected. All cases were reviewed by two senior pathologists, including one from China and the other from Singapore, according to the 2019 revision of "CCCG-WT-2016." Results: The specimens were obtained by core biopsy (n=21), primary nephrectomy (n=41), post-chemotherapy nephrectomy/resection (n=18), or biopsy/resection of metastatic/relapse/post-chemotherapy metastatic lesion(s) (n=11). The specimens of core biopsy and primary nephrectomy (n=62) all had favorable histology.Twelve post-chemotherapy nephrectomy cases were subdivided into three risk groups: low risk (n=0), intermediate risk (n=10) and high risk (n=2). Six post-chemotherapy resection cases were subdivided into 3 risk groups:low risk (n=0), intermediate risk (n=5) and high risk (n=1). The remaining 11 cases were comprised of metastatic, relapse, and post-chemotherapy metastatic lesions. The concordance rate of the two senior pathologists was 100%(91/91). Conclusions: The 2019 revision of "CCCG-WT-2016" is clearly written and easy to use. It can serve as the basis of accurate classification for clinical treatment.