Esophageal tuberculosis: role of endoscopic ultrasound in diagnosis

Esophageal involvement by tuberculosis is rare and is commonly secondary to mediastinal lymph nodal involvement. Endoscopic ultrasound (EUS) is a good modality for evaluation of both esophageal wall and mediastinal lymph nodes. The objectives were to study the role of EUS in diagnosing esophageal tuberculosis, to differentiate primary from secondary form, and to assess the response. Retrospective analysis of data over 7 years (i.e. from 2003 to 2009) was used. The study was set in a tertiary care referral institute and focused on patients diagnosed with esophageal tuberculosis. Interventions used included endoscopy, EUS, EUS-FNA (fine needle aspiration) followed by antituberculosis treatment. The main outcome measurements were symptoms, endoscopic features, EUS features, pathological yield, and response to treatment. There were 32 cases of esophageal tuberculosis. The primary symptom was dysphagia, and endoscopy showed ulcers in 18/32 (56.25%) and extrinsic bulge in 20/32 (62.5%) in middle one third of esophagus. EUS showed lymph nodes adjacent to esophageal pathology in all cases. Subcarinal region was the most common site of lymphadenopathy and they were matted, heterogeneous with predominantly hypoechoic center. Histopathology of endoscopic biopsy of ulcers and EUS-FNA of lymph nodes provided the diagnosis of tuberculosis in 27/32 (84.35%). All patients were treated with antitubercular treatment and showed good clinical, endoscopic and endosonographic response. This is a retrospective study, and PCR and culture for Mycobacterium tuberculosis were not done. Esophageal tuberculosis does not appear to be a primary disease and is most likely secondary to mediastinal nodal tuberculosis. A conglomerated mass of heterogeneous with predominantly hypoechoic lymph nodes with intervening hyperechoic strands and foci on EUS appears to be characteristic of mediastinal tuberculosis.