Abstract
INTRODUCTION: The main causes of secondary male infertility are varicocele and aging. It is rarely caused by adult-onset hypopituitarism. The onset of hypopituitarism is often due to brain tumors, trauma, surgery, or congenital disorders. CASE PRESENTATION: A 29-year-old man was admitted to the hospital with complaints of decreased libido and semen volume, which lasted for 4 months. He had no abnormalities in adolescence and has a 2-year-old child. Blood tests showed low luteinizing hormone and follicle-stimulating hormone, and semen tests showed azoospermia. Magnetic resonance imaging T1-weighted images showed swelling and enhancement effect of the pituitary gland, and lymphocytic hypophysitis was suspected. After an Insulin-thyroid-stimulating hormone releasing hormone-luteinizing hormone-releasing hormone test, a decrease in luteinizing hormone/follicle-stimulating hormone secretion was considered. We diagnosed hypogonadotropic hypogonadism due to lymphocytic hypophysitis. Currently, the patient is being treated with a hormone replacement therapy. CONCLUSION: We experienced a case of hypogonadotropic hypogonadism due to lymphocytic hypophysitis discovered by secondary infertility.