BACKGROUND: Fine-needle aspiration cytology (FNAC) has proven its value as an essential step in the diagnosis of salivary gland lesions. Although the majority of salivary gland lesions, especially those that are common and benign, can be diagnosed with ease on FNAC, limited cellularity and morphologic lesion heterogeneity can pose diagnostic challenges and lead to false-positive and false-negative diagnoses. This study presents the institutional experience of FNAC of salivary gland lesions from 2 academic centers. METHODS: A retrospective analysis was conducted on 1729 salivary gland FNAC specimens that were diagnosed over an 8-year period from January 2008 to March 2015. All samples were processed either with liquid-based cytology alone or in combination with air-dried, Diff-Quik-stained or alcohol-fixed, Papanicolaou-stained smears. RESULTS: Surgical excision was performed in 709 of 1749 FNACs (41%) that were diagnosed as nondiagnostic/inadequate (n 5 29), benign (n 5 111), neoplasm (n 5 453), atypical (n 5 15), suspicious for malignancy (n 5 28), and malignant (n 5 73). The overall concordance between cytologic and histologic diagnoses was 92.2%, with 91.8% concordance in the benign category and 89.5% concordance in cases diagnosed as suspicious for malignancy and malignant. The most frequent benign and malignant lesions were pleomorphic adenoma and squamous cell carcinoma, respectively. There were 46 false-negative and 13 false-positive results, leading to an overall specificity of 97.6% and diagnostic accuracy of 91.3%. CONCLUSIONS: FNAC is a reliable diagnostic modality for the diagnosis and management of salivary gland lesions based on its high specificity and diagnostic accuracy. Cancer Cytopathol 2016;124:388-96. V C 2016 American Cancer Society.

The results of nine FNAs of eight histologically proven schwannomas are presented. In only one of the aspirates was a diagnosis of schwannoma made; three additional cases were diagnosed as 'spindle cell neoplasm'. Two of the cases were considered to be non-diagnostic due to hypocellularity, while two cases containing cellular material raised the differential diagnosis of granulation tissue and granulomatous inflammation due to the presence of epithelioid cells and an inflammatory infiltrate, and are illustrated here. The remaining FNA was felt suggestive of branchial cleft cyst due to the presence of only cystic fluid in a neck mass. We observe that: (i) the acquisition of an adequate, representative specimen via FNA is often difficult in schwannoma, and (ii) diagnostic difficulties may be encountered in cases in which cellular material is obtained.

Purpose The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and the Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP) are scoring systems to predict metastatic potential in pheochromocytoma and paragangliomas (PCC/PGL). The goal of this study is to assess PASS and GAPP as metastatic predictors and to correlate with survival outcomes. Methods The cohort included PCC/PGL with ≥5 years of follow-up or known metastases. Surgical pathology slides were re-reviewed. PASS and GAPP scores were assigned. Univariable and multivariable logistic regression, Kaplan-Meier survival analysis, and Cox proportional hazards were performed to assess recurrence free survival (RFS) and disease specific survival (DSS). Results From 143 subjects, 106 tumors were PCC, and 37 were PGL. Metastases developed in 24%. The median PASS score was 6.5 (IQR:4.0-8.0) and median GAPP score was 3.0 (IQR:2.0-4.0). Interrater reliability was low-moderate for PASS (ICC:0.6082) and good for GAPP (ICC:0.7921). Older age (OR:0.969, p=0.0170) was associated with longer RFS. SDHB germline pathogenic variant (OR:8.205, p=0.0049), extra-adrenal tumor (OR:6.357, p&0.0001), Ki-67 index 1-3% (OR:4.810, p=0.0477), and higher GAPP score (OR:1.537, p=0.0047) were associated with shorter RFS. PASS score was not associated with RFS (p=0.1779). On Cox regression, a GAPP score in the moderately-differentiated range was significantly associated with disease recurrence (HR:3.367, p=0.0184) compared to well-differentiated score. Conclusion Higher GAPP scores were associated with aggressive PCC/PGL. PASS score was not associated with metastases and demonstrated significant inter-observer variability. Scoring systems for predicting metastatic PCC/PGL may be improved by incorporation of histopathology, clinical data, and germline and somatic tumor markers.

Background The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has established distinct diagnostic categories for reporting cytopathological findings, and each is associated with a defined risk of malignancy (ROM). However, the ROM is applied at the overall category level and is not specific for particular morphological entities within a category. Here, the diagnostic performance of the MSRSGC for pleomorphic adenoma (PA) and Warthin tumor (WT) is reported. Methods The pathology archives of 11 institutions from 4 countries were retrospectively searched to identify all salivary gland fine‐needle aspiration (FNA) biopsies with a differential or definitive diagnosis of PA or WT and all resection specimens with a diagnosis of PA or WT; only paired cases were included. All FNA diagnoses were retrospectively classified according to the MSRSGC. Results A total of 1250 cases met the inclusion criteria, and they included 898 PA cases and 352 WT cases. The ROM in the benign neoplasm category was 3.0% and 1.3% for cases with a differential or definitive diagnosis of PA and WT, respectively. The ROM in the salivary gland neoplasm with uncertain malignant potential (SUMP) category was 2.7% and 18.8% for PA and WT, respectively (P = .0277). The diagnostic accuracy for PA and WT was 95.1% and 96.1%, respectively. Conclusions The diagnostic accuracy for PA and WT on FNA is high. Furthermore, these findings highlight the difference in the ROMs associated with 2 specific differential diagnoses in the SUMP category: basaloid neoplasms and oncocytoid neoplasms.