Review Question - QID 210535

A 24-year-old woman presents to the emergency department for chest pain and shortness of breath while she was at home making breakfast. The pain is sharp and located in her chest. She thought she was having a heart attack and began to feel short of breath shortly after. The patient is a college student who recently joined the soccer team. She has no significant medical history except for a progesterone intrauterine device which she uses for contraception, and a cyst in her breast detected on ultrasound. Last week, she returned on a trans-Atlantic flight from Russia. Her temperature is 98.4°F (36.9°C), blood pressure is 137/69 mmHg, pulse is 98/min, respirations are 18/min, and oxygen saturation is 99% on room air. A physical exam reveals an anxious young woman. Cardiac and pulmonary exams are within normal limits. Deep inspiration and palpation of the chest wall elicit pain. A neurologic exam reveals a stable gait and cranial nerves 2-12 are grossly intact. Which of the following describes the most likely underlying etiology of this patient's symptoms?