The role of fine needle aspiration in the evaluation of parotid masses

Abstract

Fine needle aspiration is a safe diagnostic technique that is widely employed for lesions of the head and neck. Among head and neck sites, the parotid gland stands apart for the number, diversity and peculiarity of pathologic processes to target this structure. This matchless complexity has prompted a thoughtful discussion regarding the application of the fine needle aspiration to parotid masses--a discussion that has primarily focused on the reliability of the fine needle aspiration as a diagnostic tool, and on its utility in guiding patient management. Recent studies have confirmed a high overall accuracy rate for fine needle aspiration evaluation of parotid masses, ranging from 90 to 95%. At the same time, these soaring accuracy rates cannot be uniformly anticipated across all diagnostic scenarios. Fine needle aspiration is notoriously unreliable in recognizing the malignant nature of the parotid carcinoma, providing its precise classification, and establishing its grade. A few malignant neoplasms are particularly prone to diagnostic error. Acinic cell carcinoma is frequently interpreted as benign or even nonneoplastic; and low-grade lymphomas are often discounted as inflammatory processes. Parotid gland masses are not particularly conducive to diagnostic accuracy and precision by fine needle aspiration. Accordingly, indiscriminant reliance on the fine needle aspiration findings at the expense of the clinical, radiographic, and intraoperative findings is unwarranted. Whether one uses the fine needle aspiration routinely or selectively in patients with parotid masses, the fine needle aspiration findings should contribute to, not displace, the overall diagnostic impression.