In the cases of upper urinary tract carcinoma associated with bladder carcinoma, higher grade malignancy and lower ureter carcinoma the recurrence rate was higher and usually occurred within 3 years.

The study results suggested that the measurement of nuclear DNA of tumor cells may be helpful to ascertain the degree of differentiation and malignancy of nephroblastomas.

Both benign and malignant endocrine neoplasms demonstrate some degree of cellular pleomorphism, so it is not easy to tell benign from malignant on histologic grounds alone.