Erectile Dysfunction Associated with Severe Hypogonadotropic Hypogonadism in A Young Man with A History of Craniopharyngioma: A Case Report

Introduction. Craniopharyngioma is a histologically benign sellar-suprasellar tumor, yet the tumor and its treatment (surgery and radiotherapy) frequently damage the hypothalamic-pituitary axis, causing hypopituitarism including secondary hypogonadism. Erectile dysfunction (ED) as its presentation is rarely reported in young patients. The causal association between erectile dysfunction and severe hypogonadotropic hypogonadism cannot be fully established, but the clinical findings strongly support their relationship. Case. A 26-year-old unmarried man presented with suboptimal erections since October 2021 (Erection Hardness Score (EHS) 3), absent morning erections, normal libido, and preserved erections during masturbation. He underwent subtotal resection of a craniopharyngioma in 2022 followed by 30 fractions of radiotherapy, and had no follow-up between 2023 and 2026. Hormonal evaluation in 2026 showed FSH 0.8 mIU/mL, LH <0.1 mIU/mL, testosterone <0.05 ng/mL, and prolactin 29.8 ng/mL. Testicular ultrasound showed small bilateral testes. Brain MRI in April 2026 showed a 1.7 x 1.6 cm heterogeneous solid prepontine mass, suspected residual tumor. Conclusion. ED in a young man with a sellar tumor history warrants evaluation of the entire pituitary axis. In this case, ED was associated with severe hypogonadotropic hypogonadism and small testes, likely due to chronic gonadotropin deficiency rather than radiotherapy or surgery. Early assessment and long-term follow-up are essential for restoring sexual function and planning fertility.