Cell Block Examination Is Critical for Sarcoidosis Diagnosis by Endobronchial Ultrasound-Guided Mediastinal Lymph Node Fine Needle Aspiration

Intrathoracic sarcoidosis is often diagnosed by transbronchial lung parenchymal biopsy (TBBx), however, recent studies suggest endobronchial ultrasound-guided transbronchial fine needle aspiration of mediastinal lymph node (EBUS-FNA) is safer with superior diagnostic yield. We report our experience from 2008 to 2010 with combined EBUS-FNA and TBBx in 61 consecutive patients with clinical suspicion of sarcoidosis. One to three mediastinal lymph nodes (LN) in various locations were sampled using 21/22-gauge needles with on-site interpretation. Additional one to two specimens per site were collected in Normosol® for cell block preparations. A definitive diagnosis of sarcoidosis was made in 51 patients (84%) by EBUS-FNA/TBBx studies (46) and clinical information (5); alternative diagnoses were established in 8 patients (13 %); the last 2 patients remained suspicious for sarcoidosis without confirmatory tissue diagnosis. Of the 46 biopsy (EBUS-FNA and/or TBBx) confirmed cases, 37 (80.0%) were diagnosed by EBUS-FNA. Cell blocks prepared from all 37 patients contained diagnostic material, 10 (27.0%) were interpreted as such by on-site evaluations. The diagnostic yield of LNs at different locations varied, being 100, 68, 50 and 20% in R12, subcarinal, R4, and R11, respectively. A total of 36 patients had both EBUS-FNA and TBBx performed during the same visit. Diagnoses were identical in 15 patients (42 %). TBBx independently identified 9 cases of sarcoidosis. This study indicates that cell block preparation is valuable for EBUS-FNA diagnosis of sarcoidosis. EBUS-FNA and TBBx are effective and complimentary tools for intrathoracic sarcoidosis diagnosis. [N A J Med Sci. 2012;5(4):198-202.]