Review Question - QID 211093

A 26-year-old man presents to the office complaining of “enlarging breasts.” He reports that he has been “intensely” working out over the past 3 months. Despite losing 8 lbs, he feels that his breasts are increasing in size. He also complains of headache and fatigue. He has no chronic medical conditions except for acne vulgaris. He uses topical benzoyl peroxide and clindamycin, and he reports he takes spironolactone and an over-the-counter multivitamin. He had an orchiopexy of an undescended right testes at 8 months of age. The patient’s diet consists of 3 protein shakes a day, eggs, chicken, and broccoli. He drinks 3-4 beers on the weekends with his friends and occasionally smokes marijuana. He denies tobacco use. He states he and his longtime girlfriend have not been sexually active in the past month because he’s “just not into it.” His temperature is 98.7°F (37°C), blood pressure is 112/71 mmHg, pulse is 81/min, respirations are 12/min, and oxygen saturation is 98% on room air. On physical examination, there is proliferation of breast tissue bilaterally, without tenderness on palpation. Pubic hair is Tanner stage 4. Testicular length is 5 cm and width is 3 cm, bilaterally. A visual field defect is noted in the lateral aspects of the visual fields. Which of the following is the most likely cause of the patient's symptoms?