Influence of the cell block in the diagnostic yield of sarcoidosis b ysectorial endobronchial ultrasound

Introduction: Endobronchial ultrasound (EBUS) has been a major breakthrough in the staging of lung cancer, but its usefulness in the diagnosis of other diseases is limited by the size of the needles available. Objectives: Analyze the diagnostic yield of EBUS without ROSE, and the influence of the use of the cell block in the diagnosis of sarcoidosis. Methods: From August 2010 through November 2015, 804 EBUS were performed without ROSE. Until June 2012 a smear of the material obtained in puncture was subsequently referred to the pathology department. Thereafter the samples were prepared as cell block. Results: Among the 804 EBUS performed, we found 44 (5.4%) sarcoidosis [30 men (68.2%; mean age 51.5 ± 16.2 years) and 14 women (31.8%; 55 7 ± 18.2 years)]. In 13/44 patients (29.5%) had previously undergone another diagnostic procedure with negative results. EBUS was diagnostic in 35 patients (79.5 %). In the remaining 9 patients, the diagnosis was established by mediastinoscopy (7 patients) peripheral lymph node biopsy and transbronchial biopsy. EBUS diagnostic yield increased to 88% (32/36) when cell block was used. On the other hand it fell to 37.5% (3/8) when a conventional smear was used. An average of 1.84 lymph nodes per patient were punctured. Stations most frequently punctured were 7, 4R and 11R (in 38, 16 and 11 cases, respectively). No significant differences were found in diagnostic yield in relation with the number of stations punctured (p=0.259). Conclusions: EBUS is an useful technique for the diagnosis of sarcoidosis. The use of the cell block technique for processing EBUS samples ,improves the diagnostic yield in sarcoidosis and should be the method of choice.