Table 1. Alternate diagnosis for the pericardial effusion and respective test results .

ft4: free thyroxine, TSH: thyroid-stimulating hormone, BUN: blood urea nitrogen, eGFR: effective glomerular filtration rate, ANA: antinuclear antibodies, ANCA: antineutrophilic cytoplasmic antibodies, C3: complement component 3, C4: complement component 4, ACS: acute coronary syndrome, PPD: purified protein derivative, Hep: hepatitis, RVP: respiratory viral panel.

Diagnosis	Laboratory test result
Hyperthyroidism	fT4 = 0.994 ng/dl, TSH = 5.03 U/L (wnl)
Hyperuricemia	BUN = 9 mg/dL, creatinine = 0.3 mg/dL, eGFR = 258 ml/min/1.73m2 (wnl)
Autoimmune disorders	ANA, ANCA were negative, C4 = 10.9 mg/dl (wnl) and C3 = 75.6 mg/dl (mildly decreased)
ACS	Cardiac enzymes negative
Tuberculosis	PPD and quantiferon were negative
Hepatitis	Hep B and C serologies were negative
Other viruses	RVP negative
Trauma	No evidence of trauma on imaging
Malignancy	No malignant cells in the pericardial fluid