[A case of adult mature nephroblastic tumor]

A 22-year-old woman had a well differentiated nephroblastic tumor. The tumor was composed of mesenchymal elements with mature tubules and occasionally smooth muscle elements. None of the cellular elements showed any feature indicative of malignancy. Histologically this was similar to congenital mesoblastic nephroma, but the tumor showed an evidence of a uniform expansile growth. It was considered to be a form of mature nephroblastoma.