Please cite this article in press as: Attili F, et al. Accuracy and inter-observer agreement of the Procore TM 25 gauge needle for endoscopic ultrasound-guided tissue core biopsy. Dig Liver Dis (2015), http://dx.doi.org/10.1016/j.dld.2015.07.003 ARTICLE IN PRESS G Model YDLD-2924; No. of Pages 7 Digestive and Liver Disease xxx (2015) xxx–xxx Contents lists available at ScienceDirect Digestive and Liver Disease jou rnal h om epage: www.elsevier.com/locate/dld Digestive Endoscopy Accuracy and inter-observer agreement of the Procore TM 25 gauge needle for endoscopic ultrasound-guided tissue core biopsy Fabia Attili a , Gianluigi Petrone b , Ihab Abdulkader d , Loredana Correale a , Frediano Inzani b , Julio Iglesias-Garcia c , Cesare Hassan a , Santiago Andrade Zurita a , Guido Rindi b , J. Enrique Dominguez-Mu ˜ noz c , Guido Costamagna a , Alberto Larghi a,∗ a Digestive Endoscopy Unit, Catholic University, Rome, Italy b Department of Pathology, Catholic University, Rome, Italy c Gastroenterology Department, Foundation for Research in Digestive Diseases (FIENAD), University Hospital of Santiago de Compostela, Spain d Department of Pathology, University Hospital of Santiago de Compostela, Spain a r t i c l e i n f o Article history: Received 3 April 2015 Accepted 5 July 2015 Available online xxx Keywords: EUS-FNA EUS-FNB Inter-observer agreement Tissue acquisition a b s t r a c t Background: Scanty data on the performance of the new 25-gauge Procore TM biopsy needle are available. Methods: Consecutive patients who underwent endoscopic ultrasound-guided fine needle biopsy (EUS- FNB) using the 25G Procore TM were retrospectively retrieved. All samples were independently reviewed by 3 pathologists for the following: histological, cytological or no specimen, neoplasia, diagnostic or non-diagnostic. Diagnostic accuracy and inter-rater concordance among pathologists were calculated. Results: 94 patients underwent EUS-FNB of 101 sites (69 solid masses, 25 lymph nodes, 5 wall thickening). Forty-one biopsies (40.5%) were classified as histological samples by at least two pathologists, 29 as cytological (28.7%), 31 had no sample (30.7%). Good and almost perfect agreements among pathologists in defining cytological vs. histological samples (k 0.82; 95% CI: 0.74–0.90), diagnostic vs. non-diagnostic (k 0.95; 95% CI: 0.85–1.00) and neoplastic vs. non-neoplastic (k 0.94; 95% CI: 0.83–1.00). According to consensus rating, 61 cases were diagnostic samples (60.4%). Histological samples were more likely to lead to a correct diagnosis (OR, 4.1; 95% P = 0.027), while neoplastic lesions were less likely to be correctly classified than benign (OR, 0.11; P = 0.04). Conclusions: EUS-FNB with the Procore TM 25G needle provided samples for histological examination in only 40% of the cases, with 31% of inadequate specimens, despite excellent results in term of inter- observer variability. © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved. 1. Introduction The obtainment of a tissue core biopsy specimen for histological examination may overcome some of the limitations of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), in particular its highly variable diagnostic accuracy that is strongly dependant on the availability of rapid on-site cytopathology evaluation (ROSE) [1–3]. Cytopathology, indeed, requires a high degree of expertise and unfortunately, the access to ROSE and the availability of a on- site cytopathologist specifically trained to interpret EUS specimens is not possible in many centres [4]. This has created a barrier to the dissemination of EUS worldwide, as the lack of cytological expertise ∗ Corresponding author at: Digestive Endoscopy Unit, Catholic University, Largo A. Gemelli 8, 00168 Rome, Italy. Tel.: +39 06 30156580; fax: +39 06 30156581. E-mail address: alberto.larghi@yahoo.it (A. Larghi). has resulted in a low diagnostic accuracy and, therefore, in a limited overall perceived utility of EUS [5,6]. Tissue core biopsy specimens with preserved architecture can be critical to diagnose and fully characterize certain neoplasms, such as lymphomas and GI stromal tumours. Moreover, tissue spec- imens for histological examination also provide the opportunity (i) to easily immunostain the tissue, further improving differential diagnostic capabilities; (ii) to reach a specific diagnosis for benign diseases not always possible with a cytological sample, thus spar- ing patients from more invasive and risky procedures or costly and unnecessary follow up examinations; (iii) to potentially perform tissue profiling and/or cell culture needed to guide targeted ther- apies for individualized treatment of patients with cancer of the gastrointestinal tract [7–9]. In the past, the ability to obtain fragments of tissue for histo- logical examination with FNA needles of various diameters had been tested [10–12], and a tru-cut biopsy needle, the Quick-Core ® http://dx.doi.org/10.1016/j.dld.2015.07.003 1590-8658/© 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.