Diagnosis of mediastinal tuberculosis by using EUS-guided needle sampling in a geographic region with an intermediate tuberculosis burden

BackgroundEUS-guided FNA (EUS-FNA) or trucut biopsy (TCB) is indispensible in the diagnosis of mediastinal malignancies. Less is known, however, about the usefulness of EUS-guided sampling for nonmalignant, mediastinal tuberculosis (TB), despite the increase in the incidence of TB.ObjectiveTo assess the diagnostic yields of EUS-FNA/TCB in patients with mediastinal TB.DesignRetrospective study.SettingTertiary-care referral hospital in a geographic region with an intermediate TB burden.PatientsThis study involved 24 consecutive patients with mediastinal TB, who underwent EUS-FNA/TCB from July 2005 to September 2008.InterventionEUS-FNA/TCB.Main Outcome MeasurementsTechnical success and diagnostic yields of EUS-FNA/TCB.ResultsMediastinal lesions (mean diameter, 28.6 mm; range 17.0-49.5 mm) were targeted by using 22-gauge-needle FNA in 10 patients and 19-gauge-needle TCB in 14 patients. Before EUS, only 10 of the 24 patients had a presumptive diagnosis of mediastinal TB, whereas 11 patients were suspected of having malignancies. Six patients showed mass-like lung parenchymal lesions mimicking lung cancer, and 7 patients had a history of malignancy. Pathologic examination showed granulomatous inflammation in 16 patients (66.7%), including 10 patients with caseating granulomas. Positive microbiologic results were obtained in 10 patients (41.7%): 3 by Ziehl-Neelsen staining, 5 by Mycobacterium tuberculosis culture, and 5 by TB polymerase chain reaction (PCR) assay. EUS-FNA/TCB confirmed mediastinal TB in 20 of the 24 patients and directed 11 patients clinically suspected of having malignancies to anti-TB treatment. The diagnostic yields of FNA and TCB were similar (90.0% vs 78.6%).LimitationsRetrospective design in a tertiary-care referral hospital.ConclusionEUS-FNA/TCB is sufficiently useful to confirm mediastinal TB and can exclude suspected malignancies in TB patients.