Review Question - QID 210384

A 67-year-old woman presents to her oncologist for a follow-up appointment. She was diagnosed and treated for breast cancer 1 year ago and had recent blood work that she wants to review. The patient has a medical history of breast cancer, osteoporosis, and bulimia nervosa. She recently broke her ankle when she fell down a flight of stairs. She is currently taking fluoxetine. Her temperature is 98.7°F (37.1°C), blood pressure is 122/77 mmHg, pulse is 85/min, respirations are 12/min, and oxygen saturation is 98% on room air. A physical exam reveals a lean woman in no acute distress with an ankle brace. Her exam is unremarkable. Laboratory values are seen below. Figure A shows a test that was performed.

Hemoglobin: 13.0 g/dL
Hematocrit: 39%
Leukocyte count: 7,500/mm^3 with normal differential
Platelet count: 197,000/mm^3

Which of the following is the most likely diagnosis?