Diagnosis of Extrapulmonary TB Acid-fast staining, microscopic analysis, and mycobacterial culture of fluid and tissue samples, and, when available, nucleic acid amplification testing (NAAT) Chest x-ray Tuberculin skin test (TST) or interferon-gamma release assay (IGRA) Testing is similar to that for pulmonary TB (see Diagnosis of TB), including chest x-ray, TST or IGRA, and microscopic analysis (with appropriate staining) and mycobacterial cultures of affected body fluids (cerebrospinal fluid, urine, or pleural, pericardial, or joint fluid) and tissue for mycobacteria.