Pituitary Apoplexy Following Initial Dose of Gonadotropin-Releasing Hormone Agonists Administration: A Case Report and Review of Literature

Introduction : Gonadotropin-releasing hormone (GnRH) agonists are commonly used for hormonal treatment of advanced prostate cancer. Pituitary apoplexy is a very rare, but life-threatening reaction to this treatment. Onset of symptoms could start as early as an hour after injection. We encountered a patient with known pituitary macroadenoma who developed pituitary apoplexy shortly after leuprolide administration.

Case Description : A 90-year-old man with past medical history of prostate cancer, type 2 diabetes, chronic kidney disease and history of non-functioning pituitary macroadenoma presented to ED following sudden onset headache, vision changes, nausea and vomiting. He had received the first dose of Leuprolide an hour before symptoms started. Brain MRI showed hemorrhagic pituitary macroadenoma 3.8 cm in size. He received stress dose steroids and started on Levothyroxine given low free T4. Prolactin was normal. Patient also developed central diabetes insipidus needing desmopressin treatment. He underwent transsphenoidal pituitary resection. Pathology revealed necrotic tissue and adenoma.

Discussion : Androgen deprivation therapy remains the cornerstone of systemic therapy for advanced prostate cancer.
Few cases of pituitary apoplexy following GnRH therapy has been described. The mechanism by which GnRH administration could lead to pituitary apoplexy is not established. One study suggested that GnRh agents may stimulate the growth of pituitary adenoma and might affect the vasculature leading to hemorrhage.  Treatment can vary from surgery to conservative management considering patients age and severity of symptoms.
Sudden onset of headache, visual disturbance, mental status change following treatment with Gonadotropin-releasing hormone agonists should prompt suspicion for pituitary apoplexy. Physicians need to be aware of this complication to avoid delay in diagnosis and start appropriate management to improve outcomes.