Clinical analysis of false-negative fine needle aspiration cytology of head and neck cancers

Background: Fine-needle aspiration (FNA) cytology is frequently used for initial and/or preoperative diagnosis of tumors in the head and neck region. However, false-negative results can lead to misdiagnosis. The aim of this study was to investigate the diagnostic results of FNA in the head and neck region and the reasons for false-negative cases. Methods: The study population comprised 1,341 patients with pathologically confirmed head and neck tumors in whom FNA was performed before surgery or biopsy in the Otolaryngology Department at Numazu City Hospital between 2002 and 2016. We evaluated the false-negative FNA cytology rate as well as the site of the primary nodule, patient age and sex, sensitivity, accuracy, specificity, positive predictive value, negative predictive value, and the pathologic diagnosis after resection. Results: The rate of false-negative FNA results was 5.9% (78/1,315 cases). The main sites of falsenegative cases were the thyroid gland (n = 50), the lymph nodes (n = 16), and the salivary glands (n = 9). The sensitivity of FNA for head and neck tumors was 82.0%, with specificity and accuracy rates of 94% and 92.0%, respectively. Conclusions: We have assessed the quality of preoperative FNA cytology in head and neck tumors. To avoid misdiagnosis by FNA, it is important that the target tumor is punctured accurately. If the specimen obtained is too small, FNA should be repeated.