Expression of KRT7 and WT1 differentiates precursor lesions of Wilms' tumours from those of papillary renal cell tumours and mucinous tubular and spindle cell carcinomas.
The tumor was detected in an 70-year-old Japanese man who presented with hematuria Histologic examination showed an undifferentiated round or spindle cell carcinoma (cytokeratin 7+, cytokeratin 20+, epithelial membrane antigen+, vimentin-) with abundant lymphocytes (predominantly UCHL-1+ T cells), plasma cells, and macrophages in and around the tumor cell nests.