Clinical significance of endoscopic ultrasound-guided transoesophageal fine-needle aspiration biopsy of mediastinal lesions

Background and objective: As the mediastinum has been a region difficult to access for biopsy, mediastinoscopy has been required in most cases. In a prospective study the value of transoesophageal endoscopic ultrasound (TEUS) guided aspiration biopsy was assessed as an alternative. Patients and methods: TEUS-guided fine-needle aspirations were performed between May 1995 and March 1998 in 35 patients with mediastinal space-occupying lesions. In all cases the conventional endoscopic method or percutaneous puncture-sonography had been impossible or had failed. In one patient it had been performed after a negative mediastinoscopy. Results: In 34 patients (97%) the aspirated tissue cylinder could be evaluated histologically. There were no complications. Malignancy was demonstrated in 24 patients, and there were one case each of sarcoidosis, silicoanthracosis and two cases of retrosternal goitre. In four of seven patients the negative preoperative diagnosis was confirmed at operation or by follow-up. There were two false-negative results and in one patient there has been no definitive diagnosis. The accuracy of the method was thus 91.4%, the positive predictive value for malignancy 88.9% and the negative predictive value for malignancy 72.7%. Ultrasound alone was a poor predictor of malignancy in lymph node enlargement. Conclusion: TEUS-guided fine-needle aspiration of space-occupying mediastinal lesions is an effective and low-risk method that can in selected cases shorten the diagnostic process and avoid methods that are expensive or lead to complications such as transpulmonary biopsy guided by computed tomography or mediastinoscopy.