LAUSR

Despite early objections concerning the utility of fineneedle aspiration (FNA) for the diagnosis of salivary gland lesions, the technique has become a common procedure for the investigation of salivary gland abnormalities. At present, most of our clinical colleagues will agree that results from FNA of a salivary gland mass are useful in determining whether to perform surgery and which type of surgery to offer. An important factor in the application of FNA results to clinical management is consistency among diagnostic interpretations. Initial studies investigated the diagnostic accuracy of FNA for the recognition of specific common neoplasms such as pleomorphic adenoma or the separation of benign from malignant, but failed to specifically address how to approach cytologic material that was not diagnostic or did not provide a specific diagnosis for a given lesion. Cytologic diagnoses were formulated to closely approximate histopathologic diagnoses, but little attempt was made to develop a classification scheme to deal with “indeterminate” salivary gland specimens. The Bethesda system for thyroid cytology provides a tiered framework to classify FNA specimens not diagnostic of specific histopathologic entities. The Bethesda system also establishes cytologic adequacy criteria for categorization of unsatisfactory specimens. Other classification systems including the Papanicolaou Society of Cytopathology classification systems for pancreatic/biliary and respiratory specimens provide similar recommendations for pancreatic and respiratory specimens. In these classification systems, each diagnostic category is associated with a known risk of malignancy and with recommendations for post-cytologic study, clinical management, and treatment. Based upon the available literature, rigorous criteria were established for each of these cytologic categories allowing for improved interobserver reproducibility. At present, no similar categorization scheme and related criteria exist for salivary gland cytology. Any successful classification scheme will be tiered and include diagnostic categories which are clinically relevant and provide a framework for indeterminate FNA specimens. This is particularly relevant for salivary gland FNA where a significant cytomorphologic overlap exists between many of the benign and low grade neoplasms. This categorization system should be able to adequately characterize cystic lesions as well as contain diagnostic categories, which while indeterminate, will provide information regarding possible risk for a neoplastic process or for a high-grade malignancy. Hence, categories should be included within the scheme for classifying non-neoplastic Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, Missouri Conflict of interest: None *Correspondence to: Lester J. Layfield, MD, Professor and Chair, Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, One Hospital Drive, M263 Medical Sciences Building, Columbia, MI 65212, USA. E-mail: [email protected] Received 6 May 2016; Revised 18 August 2016; Accepted 22 August 2016 DOI: 10.1002/dc.23601 Published online 15 September 2016 in Wiley Online Library (wileyonlinelibrary.com).