Review Question - QID 108702

A 24-year-old male presents to his primary care physician with progressive chest discomfort over the last month. The discomfort is constant and sometimes associated with shortness of breath. The patient has also noticed a 12-pound unintentional weight loss over the last 6 weeks. He also thinks his breasts have increased in size. He feels more fatigued than usual but denies night sweats, palpitations, and dizziness. The patient had unilateral cryptorchidism with successful orchiopexy as an infant. He also had an episode of hepatitis A during a trip to Mexico in college. He is now a graduate student, drinks socially, and occasionally smokes marijuana. His mother has type 2 diabetes and his father has alcohol use disorder. At this visit, his temperature is 99.9°F (37.7°C), blood pressure is 121/78 mmHg, pulse is 80/min, and respirations are 14/min. There is notable bilateral gynecomastia and fullness of the anterior chest wall. His labs are shown below:

Leukocyte count: 8,000/mm^3
Hemoglobin: 13.9 g/dL
Platelet count: 155,000/mm^3

Serum:
Aspartate aminotransferase: 12 U/L
Alanine aminotransferase: 18 U/L
Alkaline phosphatase: 82 IU/L
Alpha-fetoprotein (AFP): 5,500 ng/mL
Serum ß-hCG: 31,000 IU/L

A chest radiograph is shown in Figure A. Which of the following is the most appropriate next step in management for this patient?