Sonographically Guided Fine-Needle Aspiration Biopsy of Major Salivary Gland Masses: A Review of 245 Cases

OBJECTIVE. The purpose of this study was to determine the diagnostic accuracy of sonographically guided fine-needle aspiration biopsy (FNAB) for major salivary gland tumors by comparing the biopsy results for 245 salivary gland masses with the final pathologic diagnosis after surgical excision. MATERIALS AND METHODS. This retrospective study included a total of 245 major salivary gland tumors from 244 patients who had undergone sonographically guided FNAB followed by surgical excision. To evaluate the diagnostic accuracy of FNAB, we compared the histopathologic diagnoses with the preoperative cytology results obtained from FNAB. False-negative diagnoses based on the FNAB results were reviewed. RESULTS. Two hundred fifteen aspirates (87.8%) yielded adequate cytology results. In the 215 masses from which adequate material was obtained and an unequivocal cytology result was obtained, the overall sensitivity, specificity, and accuracy of sonographically guided FNAB in differentiating malignant from benign tumors was 75.7%, 100%, and 95.8%, respectively. The false-negative diagnostic rate was 4.2% (9/215), but there were no false-positive diagnoses of malignancy. Among the 47 malignancies, only 28 cases (59.6%) were detected preoperatively by FNAB. CONCLUSION. For the preoperative evaluation of major salivary gland tumors, sonographically guided FNAB is feasible for distinguishing between benign and malignant salivary gland tumors in the subset of patients with satisfactory cytologic diagnoses. However, negative or nondiagnostic cytologic results cannot always guarantee benignity of the final diagnosis, and therefore careful consideration of the sonographic features and cytologic results is necessary to avoid false reassurance.