Video-assisted thoracoscopic surgery for the diagnosis of patients with hilar and mediastinal lymphadenopathy

Abstract

In areas where tuberculosis (TB) is rare, cases of hilar and mediastinal lymphadenopathy are often attributed to the diagnosis of sarcoidosis or a malignant process. However, these manifestations have been only sparsely reported in countries with high rates of TB. The role of simultaneous lung biopsy in the differential diagnosis of these patients using a thoracoscopic approach is also undetermined. In this prospective study, 15 adult patients with hilar and mediastinal lymphadenopathy were evaluated using video-assisted thoracoscopy during the period from May 1995 through September 1999. Biopsy of the hilar and mediastinal lymph nodes was undertaken in all 15 patients, and a wedge biopsy of the lungs was performed whenever frozen section of the nodes disclosed granulomatous inflammation. The final diagnoses included sarcoidosis (10 patients), TB (2), metastatic small cell carcinoma (2), and reactive lymphoid hyperplasia (1). No morbidity or mortality was associated with the operation. In patients with sarcoidosis and TB, most of the lymph node biopsy specimens disclosed extensive hyaline fibrosis. Lung biopsy specimens presented small non-necrotizing granulomas with multinucleated giant cells even in the absence of demonstrable parenchymal lesions. In the two patients with TB, identification of acid-fast bacilli and growth of Mycobacterium tuberculosis occurred only in lung specimens and not in specimens from lymph nodes. Video-assisted thoracoscopic surgery is a safe, simple, and effective procedure for the diagnosis of patients with hilar and mediastinal lymphadenopathy. Our results suggest that for a better differentiation between TB and sarcoidosis, an additional lung biopsy could be undertaken to provide specimens for microscopic examination and culture.