To the Editor. —
The cause of renal cell carcinoma is not well understood although chemical carcinogens, radiation, hormones, heredity, and viruses have all been implicated.1 We recently cared for a patient born with ambiguous genitalia treated for 2 years with testosterone, who presented at the relatively young age of 22 years.
Report of a Case.—
The patient was born with ambiguous genitalia. His chromosomal sex was male, and he underwent several surgical procedures on his genitalia in infancy to make him an anatomical male. He was treated with testosterone, both orally and parenterally, for 2 or more years following these surgical procedures. At age 22 years, the patient presented with flank pain, hematuria, and a right renal mass that on biopsy was found to be poorly differentiated adenocarcinoma of the kidney. At presentation, he already had widespread metastatic disease to the liver, pleura, retroperitoneum, and elsewhere. He had