[Endoscopic ultrasound-guided fine needle aspiration cytology in the mediastinum].

INTRODUCTION: Endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration in the posterior mediastinum is technically a relatively simple and safe procedure, and it can provide important information for the further management of patients. AIM: To analyze and compare the results of mediastinal endoscopic ultrasound-guided fine needle aspiration with the data available in the literature. PATIENTS AND METHODS: The authors retrospectively analyzed their prospective database on mediastinal endoscopic ultrasound-guided fine needle aspiration of 49 patients referred to their endoscopy centre between 1 November 2009 and 1 November 2012. For the fine needle aspiration 22 and 25 G needles were used. Two to six needle passes were performed in each patient. All slides were prepared at the endoscopy unit and analyzed at the cytology laboratory.
RESULTS: The authors performed mediastinal endoscopic ultrasound-guided fine needle aspiration for enlarged lymph nodes or suspected mediastinal malignancy in all but 4 patients (2 suspected oesophageal cancers, 1 suspected benign oesophageal stenosis with wall thickening and 1 cardia tumour, all with non-diagnostic endoscopic biopsies). Five patients were excluded from the analysis since fine needle aspiration was not performed in them. Benign lesions were suspected based on the endoscopic ultrasound morphology in 7, and malignant disease in 37 patients. In 3 cases samples obtained by biopsy were not informative for cytological analysis. Cytology confirmed all benign lesions and showed malignancy in 28 cases. Cytology failed to reveal malignancy in 6 patients, although it was suspected based upon endoscopic ultrasound finding. Furthermore, endoscopic ultrasound-guided fine needle aspiration provided the diagnosis in 15 of the 17 patients when bronchoscopy was non-diagnostic. The diagnostic accuracy of the EUS-FNA was the following: sensitivity 82%, specificity 100%, positive predictive value 1.0, negative predictive value 0.54. Only one infectious complication was encountered after fine needle aspiration despite antibiotic prophylaxis. DISCUSSION: Endoscopic ultrasound-guided fine needle aspiration of mediastinal pathology is an accurate, safe and technically relatively easy procedure, however it requires practice and skills in mediastinal anatomy. It has an excellent positive predictive value, a very good sensitivity, but slightly poor negative predictive value. The results of this study are concordant with the literature data. The authors suggest that at least 4 needle passes in the absence of on-site pathologist should be performed in order to minimize the number of false-negative results.