Finasteride-Related Leydig Cell Tumor: Report of a Case and Literature Review

This case report describes a 36-year-old man who developed a Leydig cell tumour (LCT) of the testis after prolonged exposure to Finasteride, a drug used for the treatment of benign prostatic hyperplasia and hair loss. Leydig cell tumours are rare neoplasms that arise from the interstitial cells of the testis and produce testosterone. Finasteride is a selective inhibitor of the enzyme 5-alpha reductase, which is responsible for the conversion of testosterone to dihydrotestosterone (DHT). Mice treated with Finasteride at higher doses developed testicular Leydig cell hyperplasia and Leydig adenomas. The appearance of gynaecomastia in patients treated with Finasteride suggests that an increased level of oestrogens has an influence on this particular side effect. The authors believe in a possible relationship between Finasteride and LCT, but further reports and research are needed to confirm such a relationship.