The Papanicolaou Society of Cytopathology System for Reporting Respiratory Cytology: To Establish Efficacy and Ease to Use in Routine Cytology Practice

Abstract

ABSTRACT Various pulmonary cytology techniques have been established, representing morphological diversity and ranging from non-invasive to minimally invasive. However, there is currently no widely accepted classification system for respiratory cytology. In 2016, the Papanicolaou Society of Cytopathology (PSC) proposed a six-tiered category system for the cytological sample obtained from the respiratory tract. The diagnostic efficacy of such a category system can help in the early diagnosis of lung cancer patients, thereby reducing mortality and morbidity. The aim of this study was to determine the diagnostic accuracy and utility of PSC guidelines for reporting respiratory cytology specimens in comparison to histopathology. This study was conducted over 6 months, from September 2023 to February 2024, on a prospective basis. Out of a total of 165 samples analyzed, 147 (89%) were bronchoalveolar lavage samples, 09 (05%) were bronchial brushings, 03 (02%) were bronchial washings, and 06 (04%) were endobronchial ultrasound-guided transbronchial fine-needle aspiration. These cytological specimens were processed and categorized according to the PSC reporting system for respiratory cytology, as non-diagnostic, benign, atypical, neoplastic (benign/undetermined malignant potential), suspicious of malignancy, and malignant. In all cases, the histopathological correlation with corresponding transbronchial or endobronchial lung biopsy was done. Our study found that 4% of the cases were non-diagnostic, 80% were benign, 13% were atypical, 2% were suspicious for malignancy, and 1% were malignant. When compared with the histological diagnosis, the sensitivity was 53.13%, the specificity was 93.23%, and the overall accuracy was 85.45%. The PSC reporting system for respiratory cytology can easily standardize reporting patterns to enhance communication between cytopathologists and clinicians, ultimately improving patient care.