The guided FNA by endobronchial ultrasound ( Endobronchial Ultrasound guided transbronchial Needle Aspiration or EBUS-TBNA) is a minimally invasive technique with an established role in the staging of lung cancer 1, and in the evaluation of intrathoracic lymph node metastases from extrathoracic primary cancer2 . There is also a role in cases of isolated hilar and mediastinal lymph nodes in which the differential diagnosis includes mostly sarcoidosis, lymphoma and tuberculosis. 3

Various studies have evaluated more recently the diagnostic yield of EBUS-TBNA specifically for sarcoidosis 4 and thoracic lymphoma 5-6. Although there is emerging data supporting the usefulness of EBUS-TBNA in the investigation of these two pathologies, the efficacy results vary according to the target populations and certain parameters. Moreover, although a large randomized study demonstrated e superiority of EBUS-TBNA over conventional bronchoscopic sampling methods [ bronchoalveolar lavage (BAL) and trans-bronchial biopsies (TBB ] for the diagnosis of sarcoidosis , 7 the results suggest that there is still room for optimizing the performance of EBUS-TBNA [b] . In the field of lymphoma, obtaining large enough specimens for adequate subtyping also remains a concern. 8

In order to improve the performance of EBUS -TBNA , new needles have been developed with the aim to provide biopsies for histological evaluation rather than purely cytological. The ViziShot FLEX © (Olympus) 19 gauge needle (19 gauge or 19G) is a large needle, which can provide both tissue and needle aspiration , and has the advantage of being more flexible.

For this study, the investigators want to compare the diagnostic yield of EBUS-TBNA using needle ViziShot FLEX 19G (1.11 mm) with that of the standard 22G needle ( NA-201SX; Olympus) , in the investigation of hilar or mediastinal lymphadenopathy suspected to be sarcoidosis or lymphoma.

Inclusion criteria

• Patient t referred for specimens by EBUS -TBNA with clinical and radiological suspicion of sarcoidosis or lymphoma , with pathological lymph node on imaging (small diameter ≥ 1.0 cm CT-scan or hyper metabolism with PET scan) in para-tracheal stations, sub-carinal and / or hilar (stations 2, 4, 7, 10, 11 and 12), right and / or left.
• Lymph nodes with a small diameter of at least 0.5 cm in CT-scan or PET / CT scan performed in the previous 4-6 weeks.
• Patient investigated in the setting of either an initial diagnosis or a suspicion of lymphoma recurrence (post-treatment).
• Patient able to consent to the procedure and to authorize us by written proxy, included in the consent form for the study, to obtain a copy of the subsequent results or radiological (PET, CT-scan, chest X-ray) or histopathological (linked with age sampled of intrathoracic lymph nodes).
• Patient deemed fit to tolerate the procedure.

Exclusion criteria

• Patient unable to give consent.
• Female patient during pregnancy
• Patient aged under 18.
• Patient with significant coagulopathy ( INR > 1.5 ; platelet count<50 000 / mm 3 ).
• Patient anticoagulated (oral or parenteral) and whose anticoagulation can not be suspended for the procedure.
• Obvious involvement of organ (s) with the possibility of confirming granulomas or suspicious cells of lymphoma by means of a procedure considered less invasive (.. e g, lymph node biopsy of cervical, supraclavicular or inguinal nodes; skin biopsy).