Testicular histology after treatment with the new antiandrogen Casodex for carcinoma of the prostate. A preliminary report.

Five men aged 55-78 years, had received Casodex 50 mg p.o. daily for seven to 12 months. Because of tumour progression orchiectomy was performed. All testes were examined with light- and electronmicroscopy. Evidence of Leydig cell hyperplasia was present in testes from three patients. However, the ultrastructural appearance of the Leydig cells was normal. The spermatogenesis was reduced in all testes, although not significantly different from controls. We believe the Leydig cell hyperplasia reflects an increased proliferative stimulation by luteinizing hormone or a direct effect of Casodex.