Malignant renal tumors in male hamsters (Cricetus auratus) treated with estrogen.

In summary, it has been found that chronic treatment of male hamsters with diethylstilbestrol is followed by the appearance of multiple cortical tumors in both kidneys. The exact origin or origins of the tumor cells is still under investigation. Ultimately, the tumors become malignant, but metastases have not been observed outside the abdominal cavity. A detailed description of the tumors will appear later, as will accounts of experimental work now in progress.