Abstract
The stimulatory effect of low doses of clomiphene citrate on the human male gonad is accepted widely. We used 25 mg. clomiphene daily for 3 weeks, with 1 week of rest, for 6 to 12 months in 650 oligospermic men without increased serum levels of follicle-stimulating hormone (less than 20 IU/1.). Unilateral testicular neoplasm developed in 2 subjects. Although a definite cause-and-effect relationship between treatment and tumor development cannot be assigned the possible risk of tumor development in men undergoing long-term clomiphene treatment is suggested. Since clomiphene administration or gonadotropin treatment might enhance tumor development in men, patients at risk undergoing such therapy should be examined frequently and when a testicle enlarges a malignant tumor must be ruled out.