Parotid Swellings Misdiagnosed by Fine Needle Aspiration Cytology: It's Impact on Patient Management

Background Fine needle aspiration cytology (FNAC) is an important tool for diagnosis of parotid swellings and the correct diagnosis is key to the appropriate treatment. Objective To evaluate the impact of the misdiagnosis of parotid swellings by fine needle aspiration cytology on patient management. Method It was a descriptive cross-sectional study carried out by the reviewing the medical record of patients who had undergone parotid surgery from January 2015 to December 2022 in the Department of ENT-Head and Neck Surgery, TU Teaching Hospital, Nepal. Patient demographic data, fine needle aspiration cytology result and histopathological report were collected for evaluation. The study was approved by institute's institutional review committee. Result Of the total of 80 patients included in the study, sixteen cases were misdiagnosed by fine needle aspiration cytology compared to the histopathological report. The rate of false positive and false negative cases in the study was 3.75% and 5%. The false positive cases received extensive surgery than would be required. However, due to the use of magnetic resonance imaging for evaluation, false negative cases did not receive under treatment. In general, 5% of the patients had undergone unnecessary surgery due to misdiagnoses. Conclusion Fine needle aspiration cytology misdiagnoses about one in five cases of parotid swelling. Misdiagnosis leads to incorrect or inadequate treatment. None of the investigations is very sensitive and specific in identifying the salivary gland swellings. Therefore, clinical awareness, radiological characteristics and pathological information should be taken into account together for final treatment planning.