ABSTRACT
Introduction: The Papanicolaou Society of Cytopathology System for reporting Pancreaticobiliary Cytology (PSCPC) is a reliable method to classify pancreatic fine needle aspiration cytology (FNAC) smears. However, it is not without practical problems which can diminish the diagnostic accuracy of the cytological diagnosis. Aims and Objectives: To determine the diagnostic pitfalls while reporting cytomorphology of pancreatic lesions according to PSCPC on correlating FNAC findings with histopathology. Materials and Methods: Retrospective analysis of pancreatic FNAC smears received in the Department of Pathology of our tertiary care institute over a period of 2 years was done. The cytological diagnoses were classified according to the Papanicolaou Society of Cytopathology system of reporting pancreaticobiliary cytology and correlated with histopathology. The reasons of cyto-histological discordance were analyzed. Results: Out of 50 cases in which both FNAC and biopsy of pancreatic lesions were done, 34 cases were positive/malignant (Category VI), eight cases were suspicious for malignancy (Category V), three cases were neoplastic (Category IV), two cases were atypical (Category III), two cases were negative for malignancy (Category II), and one case was non-diagnostic (Category I). Out of 50 cases, histopathology was non-diagnostic due to inadequate material in six cases. The cytological diagnoses were compared with histopathology in the remaining 44 cases. Categories III, IV V, and VI were considered as positive for neoplastic pathology. The sensitivity of FNAC to predict neoplastic pathology was 97.5%, while the specificity was 25%. The positive predictive value was 92.9%. Two cases reported as atypical (Category III) turned out to be adenocarcinoma on histopathology. One case reported as neuroendocrine tumor and two cases reported as adenocarcinoma on cytology displayed features of chronic pancreatitis on histology. One case reported as neoplastic mucinous cyst (Category IV) turned out to be adenocarcinoma on histology (limited concordance). Conclusion: The cytopathologist needs to be wary of the potential pitfalls to improve the diagnostic accuracy of FNACs.
ABSTRACT
INTRODUCTION: Fine Needle Aspiration cytology (FNAC) and core needle biopsy (CNB) are rapid, minimally invasive and useful techniques to evaluate mediastinal lesions. OBJECTIVES: To compare cytopathology with histopathology of mediastinal lesions and analyse reasons for discordance. MATERIAL & METHODS: Retrospective analysis was done in a tertiary care centre in North West India over a period of seven and half years from 1stJuly 2016 to 31st December 2023. Only those patients who had undergone FNAC and trucut biopsy of mediastinal masses were included. The cytopathology and histopathology slides were studied to analyse causes of discordance. Sensitivity, specificity, positive and negative predictive values of FNAC were calculated keeping histopathology as gold standard. RESULTS: Out of 57 cases analysed, eight cases were non diagnostic on cytology. Cytology could effectively classify a lesion as non neoplastic (7) or neoplastic (42). For further subtyping, histopathology and Immunohistochemistry (IHC) were required. Out of 27 cases of cytological - histopathological discordance, 8 cases had sampling error, 15 cases had limited concordance where FNAC could predict possibility of tumor and 4 cases were discordant where subtyping of malignancy varied on CNB. Sensitivity of FNAC to predict definite diagnosis was 90.2 %, specificity was 50 %, positive predictive value of FNAC to give a definite diagnosis was 93.9 %, negative predictive value was 37.5 %. CONCLUSION: Evaluation of mediastinal masses requires combination of cytology, histopathology and ancillary techniques like IHC. FNAC and CNB are complementary modalities and both are essential for rapid, accurate and comprehensive diagnosis.
