Evaluation of the Utility of Rapid On-site Cytology Performed by an Interventional Pulmonologist During EBUS-TBNA.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established minimally invasive technique for the diagnosis and staging of mediastinal and hilar lymphadenopathy, particularly in patients with suspected or confirmed lung cancer. The procedure enables real-time sampling of lymph nodes and peribronchial lesions, providing cytological material for diagnostic evaluation and, when necessary, for ancillary studies such as immunohistochemistry and molecular testing. Ensuring the adequacy and representativeness of collected samples is critical, especially in the context of personalized oncology, where therapeutic decisions rely on accurate histological and molecular characterization.

Rapid On-Site Evaluation (ROSE) is an intra-procedural technique that involves the immediate cytological assessment of aspirated material to determine sample adequacy and provide a preliminary diagnostic impression. Traditionally, ROSE is performed by a cytopathologist or cytotechnologist present during the procedure. However, the limited availability of these professionals in many centers restricts the routine use of ROSE, leading to potential inefficiencies such as unnecessary needle passes, longer procedure times, and suboptimal sample collection.

This study is a prospective, observational, single-center investigation conducted within routine clinical practice, aimed at evaluating the feasibility and diagnostic performance of ROSE when performed by an interventional pulmonologist. The study is designed as a quality improvement initiative (no-profit) and focuses on assessing whether appropriately trained pulmonologists can reliably perform on-site cytological evaluation during EBUS-TBNA procedures.

During each procedure, samples are obtained according to standard clinical indications. A portion of the collected material is processed following routine cytopathological workflows, including fixation in formalin and preparation of cell blocks for definitive diagnosis. An additional portion of the specimen is smeared into glass slides, rapidly stained (e.g., Diff-Quik), and immediately evaluated on-site by the interventional pulmonologist. The pulmonologist assesses both the adequacy of the specimen and provides a preliminary classification based on cytomorphological features.

Specimens are categorized into predefined diagnostic groups, including: diagnostic (presence of clearly atypical or malignant cells), adequate negative (presence of sufficient lymphoid elements without atypia in lymph node samples), inadequate (insufficient cellular material or absence of representative elements), and indeterminate/suspicious (presence of atypical features not sufficient for a definitive diagnosis). The final cytopathological evaluation, performed by an experienced cytopathologist, serves as the reference standard. Blinding procedures may be applied to minimize bias in interpretation.

The study aims to evaluate the level of agreement between the pulmonologist's on-site assessment and the final cytopathological diagnosis, focusing on both adequacy and diagnostic interpretation. The results are expected to inform the potential role of pulmonologist-performed ROSE as an alternative model in settings where cytopathology support is limited.

Data collection is performed using a secure, web-based electronic data capture system (REDCap), which ensures structured data entry, auditability, and compliance with Good Clinical Practice (GCP) and applicable data protection regulations (including GDPR).