Gonadotropin-releasing hormone agonist used for prostate cancer has the potential to induce pituitary apoplexy, particularly in the setting of a preexisting pituitary adenoma.<h4>Case presentation</h4>A 76-year-old male with prostate cancer initially chose active surveillance; however, prostate-specific antigen (PSA) elevation required hormonal therapy 5 years later. This evidence concerns the gene KLK3 and pituitary gland adenoma.