Performance of Rapid Intraoperative Cytology for Lung Tumours

Summary: Introduction: The value of cytology in the setting rapid on-site evaluation (ROSE) has already been demonstrated, especially during fine needle aspiration (FNA) procedures. We are hereby presenting an evaluation of the performance of rapid intraoperative cytology during lung cancer surgeries at the ""Hygeia- Mitera"" hospital, where it is routinely used alongside frozen section examination. Materials and Methods: The cytopathology department's database of the ""Hygeia-Mitera"" hospital for the six years period 2017-2022 was queried to retrieve all cases where rapid intraoperative cytology was performed during lung surgery. Subsequent histological diagnoses were also obtained, when available, and correlated with the initial cytological reports. Rapid intraoperative cytology is ordered as a first step evaluation by thoracic surgeons due to its perceived advantages in speed and reliability and is subsequently complemented by frozen sections. Results: Our search retrieved 414 cases of rapid intraoperative cytology. The initial cytological diagnoses were re-categorized according to the ""WHO Reporting System for Lung Cytopathology"" as follows: 12 (2.9%) nondiagnostic, 94 (22.7%) benign, 22 (5.3%) atypical, 35 (8.5%) suspicious for malignancy and 251 (60.6%) malignant and correlated with the histological reports (Table 1). In our database, the risk of malignancy (ROM) of each of the diagnostic categories of the WHO Reporting System for Lung Cytopathology was calculated to be 57.1% (Nondiagnostic), 21.4% (Benign), 55% (Atypical), 97% (Suspicious for Malignancy) and 100% (Malignant) (Table 2). To assess accuracy, nondiagnostic cytology cases and those lacking corresponding histological diagnoses were excluded (n=389). Within this group, rapid intraoperative cytology demonstrated high sensitivity (94.3%), specificity (86.8%), positive predictive value (PPV, 96.7%), negative predictive value (NPV, 78.6%), and overall accuracy (92.8%). Conclusions: This evaluation of rapid cytology for the intraoperative assessment of lung tumors in this institution strongly points to its potential use as a reliable substitute or complement of frozen sections' examination in many cases.