National Journal of Laboratory Medicine (Jul 2020)
Critical Analysis of Pitfalls in Cytological Diagnosis of Salivary Gland Lesions: Experience in a Tertiary Care Centre
Abstract
Introduction: Fine Needle Aspiration Cytology (FNAC) is an important diagnostic method which is used to evaluate and diagnose salivary gland pathologies. Diverse morphological patterns and overlapping features of benign and malignant lesions makes diagnosis a challenge. Application of classic cytological diagnostic criteria and awareness of pitfalls may help to improve performance characteristics of salivary gland FNAC. Accuracy depends on experience; an accurate diagnosis provides superior advantages to clinicians and then to the patients. This study discusses pitfalls in salivary gland FNACs of cases received at a tertiary care hospital. Aim: To compare the preoperative FNAC findings with the histopathological diagnosis and assess causes of discordance and potential pitfalls of salivary gland lesions in cytology. Materials and Methods: A retrospective study was conducted in the Department of Pathology, Yenepoya Medical College, Mangalore, Karnataka, India. All salivary gland FNAC smears received from January 2017 to June 2018 were reviewed. Discrepancies were evaluated by two pathologists, taking histopathological diagnosis as gold standard to establish the possible reason for discordance. Results: In the present study, out of 54 cases of salivary gland FNAC, cyto-histological correlation was available in 22 cases, which formed the study group. Pleomorphic Adenoma (PA) was the commonest lesion in the study group. Out of 22 cases, 8 (36.4%) cases showed discordance. Discordance was seen mostly for Mucoepidermoid Carcinoma (MEC) (4/8), one case each of Salivary Duct Carcinoma (SDC), PA, basal cell adenocarcinoma and Acinic Cell Carcinoma (ACC). Discrepancies were mainly interpretation based. Conclusion: FNAC is recommended as a very useful, quick, reliable and minimally invasive technique in preoperative diagnosis of salivary gland lesions. Inspite of high sensitivity, there are certain pitfalls due to the misleading diagnostic yields which should be kept in mind. Pitfalls could be due to sampling error, technically suboptimal slides, cystic lesions and misinterpretation of smears.
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