Abstract
BACKGROUND: A 29-year-old man presented to a clinic with infertility and hypogonadism in the setting of morbid obesity. On presentation, he had notable gynecomastia and a low testicular volume. The patient's weight was 154 kg and his height was 168 cm (BMI 54.5 kg/m(2)). Before referral to the clinic, the patient had been treated with testosterone therapy for 4 months for hypogonadism. This treatment had caused his initially low sperm concentration to fall to undetectable levels. INVESTIGATIONS: Measurement of reproductive hormone levels, pituitary MRI, and semen analysis. DIAGNOSIS: Infertility secondary to hypogonadotropic hypogonadism and an elevated estrogen:testosterone ratio. MANAGEMENT: Treatment with an aromatase inhibitor, anastrozole, led to normalization of the patient's testosterone, luteinizing hormone and follicle-stimulating hormone levels, suppression of serum estradiol levels, and to normalization of spermatogenesis and fertility.