Our results of mediastinal endoscopic ultrasound-guided fine needle aspiration

Introduction: Endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration (EUS-FNA) in the posterior mediastinum is technically a relatively simple procedure, however the anatomical location is ususally unfamiliar for the practicing gastrointestinal endoscopist. The aim of the present study was to analyze our results on mediastinal EUS-FNA.

Patients and Methods: We retrospectively analyzed our data on mediastinal EUS-FNA of 31 patients referred to our Endoscopy Center between 1 January 2010 and 1 January 2012. For the FNA 22 G Olympus EZ Shot and 22 and 25 G Boston Scientific Expect needles were used. Two-six needle passes were performed in each patients. All slides were prepared at the Endoscopy Unit but examined at the Pathology Department.

Results: We performed mediastinal EUS-FNA for enlarged lymph nodes or suspected mediastinal malignancy in all but 1 patient (suspected oesophageal cancer with undiagnostic biopsies). We suspected benign lesions based on the EUS morphology in 5, and malignant disease in 26 of them. The cytology confirmed all benign lesions and showed malignancy in 19 cases. 4 slides were not informative for cytological analysis. EUS suspected but cytology did not show malignancy of the enlarged mediastinal lymph node of a patient with central pulmonary tumour. In 1 patient PET/CT was equivocal, the EUS showed suspicion, but the cytology did not prove malignancy, and the patient was lost to follow up. The latter two were counted as false negative EUS-FNA diagnoses. The diagnostic accuracy calculation was based on the 27 cases where the slides were informative: sensitivity 86%, specificity 100%, positive predictive value (PPV) 1.0, negative predictive value (NPV) 0.63. No complications were encountered.

Discussion: EUS-FNA of mediastinal pathology is accurate, safe and usually technically easy procedure, however it requires practice and skills of mediastinal anatomy. Our results are concordant with the literature. EUS-FNA has an excellent PPV, very good sensitivity, but slightly poorer NPV. Broader information of its usefulness is recommended especially for pulmonologists.