Comparison of preoperative diagnostic accuracy of fine needle aspiration and core needle biopsy in parotid gland neoplasms

Abstract

Background: Fine needle aspiration (FNA) and core needle biopsy (CNB) are two commonly used approaches for the diagnosis of suspected neoplastic parotid gland lesions. We aimed to compare the diagnostic efficiency of FNA and CNB performed with ultrasound guidance preoperatively for the diagnosis of parotid neoplasms.

Methods: We retrospectively analysed the preoperative specimens of 113 patients (66 FNA, 47 CNB) who underwent surgical excision at our institute between 2014 and 2017. Patient selection was based on lesion type and dimension, preliminary and final pathology, imaging characteristics, clinical course, and treatment data for accurate statistical analysis. The final diagnosis was based on surgery in all of the patients. We compared the diagnostic accuracy of FNA and CNB regarding the correct tissue-specific diagnosis of benign and malignant tumours. The recurrence and complication rates were analysed to determine the safety of each technique.

Results: Among the 113 patients, the average follow-up period was 65.4 (50-88) months. Seventy-one patients (62.8%) were males, and the median age was 50 years. The most common type of surgery was superficial parotidectomy (83.2%), and the median tumour size was 30.0 mm. Pleomorphic adenoma was the most frequent neoplasm. The diagnostic rates of preoperative pathological evaluation of FNA and CNB samples were 68.2% and 91.5%, respectively. The sensitivity, specificity, and positive predictive value of FNA for detecting malignant lesions were 40, 100, and 100%, respectively, and those of CNB were 100, 100, and 100%, respectively. Only one complication occurred (haematoma) in the biopsy area after CNB. No recurrences were seen after CNB and FNA during the follow-up period.

Conclusion: Our findings suggest that the diagnostic ability, sensitivity, and specificity of CNB are excellent compared with those of FNA. The only disadvantage of CNB is the need for experienced staff and good-quality equipment. The complication rates of each technique are very low, and the risk of tumour tract seeding is controversial. CNB should be considered the technique of choice when a nodule is detected in the parotid glands.

Keywords: CNB; Core needle biopsy; FNA; Fine needle aspiration; Parotid gland; Parotidectomy; Ultrasound-guided needle biopsy.