Endoscopic ultrasound (EUS) features of mediastinal tubercular lymphadenopathy

Endoscopic ultrasound (EUS) findings in mediastinal tubercular lymphadenopathy have not been well characterized. This study aims to assess the accuracy of EUS findings of patchy anechoic or hypoechoic areas and hyperechoic foci in mediastinal lymph nodes for the diagnosis of mediastinal tuberculosis.

Forty-two patients with enlarged mediastinal lymph nodes who underwent EUS guided FNA were included. EUS findings were retrospectively reviewed for size, patchy anechoic or hypoechoic areas and hyper echoic foci. The final diagnosis was based on cytological examination of aspirate as well as clinical follow-up.

Final diagnosis was tuberculosis in 22 patients and non-tubercular diagnosis in the rest. Hyperechoic foci in the lymph nodes was seen in 77.2% of patients with tubercular mediastinal lymphadenopathy and in 5% of patients with non-tubercular mediastinal lymphadenopathy (p=0.00). Patchy anechoic or hypoechoic areas were seen in 40.9% patients with tubercular mediastinal lymphadenopathy whereas none of the patients with non-tubercular mediastinal lymphadenopathy presented these (p=0.01). The patchy anechoic or hypoechoic areas or hyperechoic foci in the mediastinal lymph nodes had accuracies of 69.0% and 85.7%, respectively, for the diagnosis of tuberculosis.

Patchy anechoic or hypoechoic areas or hyperechoic foci in the mediastinal lymph nodes on EUS are important signs of mediastinal tubercular lymphadenopathy and EUS guided FNA is a useful modality for diagnosis of mediastinal tuberculosis.