A 31-year-old married white man presents with breast enlargement and tenderness of 6 months’ duration

A 31-year-old married white man presents with breast enlargement and tenderness of 6 months’ duration. He reports normal sexual functions and has 2 biologic children. He is not taking any medications, he does not smoke or drink, and he has not used any recreational drugs. Physical examination fi ndings are unremarkable except for bilateral, tender, symmetrical gynecomastia. His secondary sex characteristics, external genitalia, and testicular size and consistency are all normal. Laboratory test results are normal for serum total and free testosterone, prolactin, thyrotropin, and dehydroepiandrosterone-sulfate (DHEA-S). Other results (and reference ranges) include serum estradiol 78 pg/mL (10–40 pg/mL) and ß -human chorionic gonadotropin (hCG) 50,000 IU/L ( following tests is the most appropriate next step? a. Ultrasonography of the testicles b. Computed tomography imaging of the adrenals c. Magnetic resonance imaging of the pituitary d. Mammography e. Liver biopsy