Sauter, Jennifer L

AbstractObjectivesLong-term follow-up is important for determining performance characteristics of thyroid fine-needle aspiration (FNA).MethodsHistologic or 3 or more years of clinical follow-up was used to calculate performance characteristics of thyroid FNA before and after implementation of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) classification was also investigated.ResultsFollow-up was obtained for 1,277/1,134 and 1,616/1,393 aspirates/patients (median clinical follow-up, 9.9 and 4.4 years, pre- and post-TBSRTC, respectively). Nondiagnostic, suspicious for follicular neoplasm, and suspicious for malignancy (SFM) diagnoses decreased and benign diagnoses increased post-TBSRTC, while atypical rate remained less than 1%. Negative predictive value for benign nodules and positive predictive value (PPV) for SFM increased significantly. Eleven nodules were reclassified as NIFTP, slightly decreasing PPV/risk of malignancy (ROM).ConclusionsAppropriate ROM for thyroid FNA can be achieved through application of TBSRTC terminology with minimal use of atypical category.

BACKGROUNDThe objective of the current study was to establish a process for validating immunohistochemistry (IHC) protocols for use on the Cellient cell block (CCB) system.METHODSThirty antibodies were initially tested on CCBs using IHC protocols previously validated on formalin‐fixed, paraffin‐embedded tissue (FFPE). Cytology samples were split to generate thrombin cell blocks (TCB) and CCBs. IHC was performed in parallel. Antibody immunoreactivity was scored, and concordance or discordance in immunoreactivity between the TCBs and CCBs for each sample was determined. Criteria for validation of an antibody were defined as concordant staining in expected positive and negative cells, in at least 5 samples each, and concordance in at least 90% of the samples total. Antibodies that failed initial validation were retested after alterations in IHC conditions.RESULTSThirteen of the 30 antibodies (43%) did not meet initial validation criteria. Of those, 8 antibodies (calretinin, clusters of differentiation [CD] 3, CD20, CDX2, cytokeratin 20, estrogen receptor, MOC‐31, and p16) were optimized for CCBs and subsequently validated. Despite several alterations in conditions, 3 antibodies (Ber‐EP4, D2‐40, and paired box gene 8 [PAX8]) were not successfully validated.CONCLUSIONSNearly one‐half of the antibodies tested in the current study failed initial validation using IHC conditions that were established in the study laboratory for FFPE material. Although some antibodies subsequently met validation criteria after optimization of conditions, a few continued to demonstrate inadequate immunoreactivity. These findings emphasize the importance of validating IHC protocols for methanol‐fixed tissue before clinical use and suggest that optimization for alcohol fixation may be needed to obtain adequate immunoreactivity on CCBs. Cancer (Cancer Cytopathol) 2016;124:89‐99. © 2016 American Cancer Society.