A 42 year old migrant Mexican farm worker comes to the emergency room complaining of fever and chest pain. The pain started 3 days ago and is substernal and does not radiate. As you examine the patient you notice that the pain seems to get worse while he is laying down, and improves somewhat when you ask him to sit up in the bed. On review of systems, he states that he has experienced a 15lb unintentional weight loss over the last 3 months and has also been having a cough, night sweats and intermittent fevers during this time. Vital signs are T 38.8 BP 134/82 P 88 RR 20 O2 97%. Exam reveals a man seated uncomfortably in the bed with mild bitemporal wasting. Sclera are anicteric and mucous membranes are moist. The oropharynx is clear without exudates or erythema. There is no cervical lymphadenopathy. Chest wall is nontender. Cardiac auscultation reveals normal S1 and S2 with a 2 part friction rub heard substernally. Lung exam is positive for coarse breath sounds on the left. Routine labs, CXR and EKG are all ordered and are pending."
Question 1 (Step 1 & Step 2-CK): What is the most likely etiology of this patient's chest pain?
Question 2 (Step 2-CK): Elevation of which of the following markers is most consistent with the process described above?