Sarcoidosis is a multisystem granulomatous disease of unknown cause that is diagnosed more reliably in the presence of the following three criteria: a compatible clinical-radiological presentation; the demonstration of a nonnecrotizing granulomatous inflammation in at least one tissue sample; and the reliable exclusion of alternative causes of granulomatous disease. Because thoracic involvement is highly prevalent, bronchoscopy with its ancillary techniques of sampling the airways (endobronchial biopsy), lung parenchyma (transbronchial lung biopsy), or intrathoracic lymph nodes (conventional transbronchial needle aspiration, endosonography) has the highest diagnostic yield, unless more easily accessible sites (ie, superficial lymph nodes, conjunctiva, skin) are available. In the last decade, the possibility to sample under ultrasound guidance (endosonography) the intrathoracic lymph nodes through the airways (endobronchial ultrasound guided, EBUS-TBNA) or through the esophagus (endoscopic ultrasound-guided fine needle aspiration, EUS-FNA/EUS-b-FNA) has revolutionized the diagnostic approach to sarcoidosis.
Learning Objectives:• Discuss the clinical reasons why endosonography (EBUS, EUS-B) has become the first-step method for the pathological confirmation of the clinical suspicion of sarcoidosis.
• Discuss the possible drawbacks associated with the use of endosonography in sarcoidosis.
• Discuss the main technical aspects (ie, needle size, airways vs esophageal route, number of needle passes, number of revolution within the target lymph node, processing of the samples, and the role of the pathologist) that influence the diagnostic success of EBUS-TBNA and EUS-B-FNA.