Background: A study was undertaken to evaluate the clinical impact of endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) in patients with mediastinal masses suspected of malignancy.
Methods: From April 1993 to December 1999, 84 patients were referred for EUS-FNA. In all patients CT scanning had shown a lesion of the mediastinum suspected of malignancy located adjacent to the oesophagus. In order to evaluate the clinical impact of EUS-FNA, the history of each patient up to referral for EUS-FNA was reviewed. A board of thoracic specialists was asked to decide the further course of the patient if EUS-FNA had not been available, and this diagnostic strategy was compared with the actual clinical course after EUS-FNA.
Results: For the 79 patients in whom sufficient verification was obtained, EUS-FNA had a sensitivity of 92%, specificity of 100%, PPV of 100%, NPV of 80%, and an accuracy of 94% for cancer of the mediastinum. In 18 of 37 patients (49%) a thoracotomy/thoracoscopy was avoided as a result of EUS-FNA, and in 28 of 41 patients (68%) a mediastinoscopy was avoided. The direct result of the cytological diagnosis obtained by EUS-FNA was that a final diagnosis of small cell lung cancer was made in eight patients resulting in referral for chemotherapy, and in another three patients with benign disease specific treatment could be initiated (sarcoidosis, mediastinal abscess, and leiomyoma of the oesophagus).
Conclusions: EUS-FNA is a safe and sensitive minimally invasive method for evaluating patients with a solid lesion of the mediastinum suspected by CT scanning. EUS-FNA has a significant impact on patient management and should be considered for diagnosing the spread of cancer to the mediastinum in patients with lung cancer considered for surgery, as well as for the primary diagnosis of solid lesions located in the mediastinum adjacent to the oesophagus.