Magnetic Resonance Imaging versus Fine Needle Aspiration Biopsy in the Differential Diagnosis of Neoplastic Parotid Gland Lesions

Abstract

Objective: This research aims to compare fine needle aspiration biopsy (FNAB) with magnetic resonance imaging (MRI) in differentiating between neoplasms found within the parotic gland. Methods: Using a retrospective methodology, records were reviewed from 74 cases who had surgery for a parotid neoplastic lesion between January 2013 and November 2018. 41 cases were men and 33 women, with a mean age of 51.3 +/- 12.8 years. In each instance, comparison was made between the eventual histopathological diagnosis and the results of evaluation by FNAB or MRI prior to surgery. The comparison looked at how the two methods influenced surgical choice, their ability to distinguish between malignant and benign lesions and power to predict histopathological subtype. Results: 57 cases (out of 74) represented benign lesions (77%), whilst 17 were malignant (23%). Superficial parotidectomy was carried out on 54, and total parotidectomy on 20 individuals. FNAB had a sensitivity in the detection of malignancy of 73.3% with a specificity of 100%. The accuracy was 93.4%. MRI, on the other hand, had a sensitivity in the detection of malignancy of 81.2% with a specificity of 90.5%. The accuracy was 88.4%. Amongst benign lesions found, the most frequently occurring were pleomorphic adenome and Warthin's tumour. MRI could accurately identify the histopathological type in 90% of such cases, whilst FNAB identified 89.1%. Conclusion: In distinguishing between benign and malignant neoplastic lesions of the parotid gland, FNAB and MRI have similar abilities. Although MRI is unable to adequately predict the histopathological subtype in malignant lesions, unlike FNAB, its role in surgical planning and tumour staging remains highly significant.