A case of hypogonadtropic hypogonadism due to hypophysitis discovered by secondary male infertility

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.