RT Journal Article SR Electronic T1 On site evaluation of biopsy smears in respiratory samples for the diagnosis of lung cancer JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 4262 DO 10.1183/13993003.congress-2022.4262 VO 60 IS suppl 66 A1 E Barrio Herraiz A1 A J Solis Solis A1 T Zapata Comas A1 P Trias Sabriá A1 M Ávila Terzi A1 N Mateos Mari A1 P Serra Mitjà A1 C Centeno Clemente A1 R Tazi Mezalek A1 J Abad Capa A1 A Rosell Gratacós A1 F Andreo García YR 2022 UL http://erj.ersjournals.com/content/60/suppl_66/4262.abstract AB Introduction: The serum smear of the bronchial biopsy was shown to improve the diagnostic performance of bronchoscopy in endobronchial tumors by 4.8% (Rosell et al. Eur Respir J. 1998), but its result is not immediate.Objective: to study the feasibility of smear cytology of different types of bronchoscopic and transthoracic biopsies with microscopic on-site evaluation (MOSE), in patients with suspected lung cancer.Methods: Prospective study from biopsy samples obtained by transbronchial biopsy (TBB), endobronchial biopsy, and thoracic ultrasound-guided tru-cut. MOSE was performed by cytotechnics and cytologist. In 7 of 11 cases (63.6%) the evaluation was done by telecytology.Results: 18 patients were included. Radial EBUS-guided BTB was performed in 5, bronchial biopsies in 4, Archimedes®️-guided BTB in 3, fine bronchoscope in 2, and thoracic ultrasound-guided lung or mediastinal mass tru-cut in 4. The MOSE of the biopsy smear was positive in 14 cases, suspicious in 1, uncertain in 1, and negative in 2.The MOSE was coincident with the biopsy smear in 15/18 cases (83.3%). In one case the MOSE was negative while the final result was carcinoma, in another case it was positive and the final smear reported few suspicious atypical cells, and in the third it was suspicious showing malignant cells suggestive of adenocarcinoma in the cytology.In one case (5.6%) the biopsy smear was diagnostic of squamous cell carcinoma while the biopsy only showed necrosis and atypia.Conclusions: Performing biopsy smears with MOSE in different types of respiratory samples is a feasible technique for its performance in the clinical practice. In 83% of the samples, it corresponded to the definitive cytological result.FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 4262.This article was presented at the 2022 ERS International Congress, in session “-”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).