[Diagnostic accuracy of fine needle aspiration cytology in parotid tumours]

Fine needle aspiration cytology (FNAC) is a globally accepted technique in the preoperative evaluations of head and neck tumours; however, the effectiveness in the interpretation of salivary glands neoplastic lesions is still controversial. The objective of this study consisted of assessing the efficacy of FNAC in preoperative diagnosis of parotid tumours.

This retrospective study was conducted using 93 patient samples with parotid gland tumoral pathology, treated at the Otorhinolaryngology Department in our institution during the 2007-2011 period. Preoperative FNAC was employed and the patients subsequently submitted to surgical excision with histopathological diagnosis of the specimen. Cytology results were classified as negative for malignancy, positive for malignancy or insufficient sample, and later compared with the definitive histological diagnosis.

The mean age of the studied sample was 52.9 years (range: 11 to 88 years); 55.9% were men. The FNAC showed significant sensitivity of 57.1%, with a specificity of 95.1%, for detecting malignancy in parotid gland tumours. The positive and negative predictive values for malignancy were 50 and 96.3%, respectively.

FNAC is considered a simple test but of limited use for diagnostic guidance in tumour pathology of the parotid gland in our environment, mainly because of its low sensitivity. However, the high specificity and high negative predictive value of FNAC makes it a more accurate test in benign or negative result cases.