Faculty Bibliography

Introduction: The Thyroid Imaging Reporting and Data System (TI-RADS) was designed to standardize risk stratification of thyroid nodules by ultrasonographic criteria and categorize nodules as TR1-TR5 to designate nodules for fine needle aspiration (FNA) or surveillance. Thyroid FNAs are classified according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) (categories TBS I-VI) with an associated risk of malignancy and management guideline. We utilize Thyroseq-V3 molecular testing for indeterminate cytology cases (TBS III- V). Our aim was to correlate indeterminate thyroid FNAs with TI-RADS scores and molecular results to determine if TI-RADS is accurately identifying nodules for biopsy.
Material(s) and Method(s): A retrospective review of thyroid nodules from 1/1/2018-8/30/2018 was performed. Patients with ultrasound (US) reports including TI-RADS scores, FNA reports with indeterminate cytology (TBS-III, TBS-IV and TBS-V) and molecular testing were included.
Result(s): 370 of 1000 thyroid nodules had US reports with TI-RADS scoring and concurrent cytology. 47 cases had indeterminate cytology (TBS-III n=37, TBS-IV n=7 and TBS-V n=3) and reflex molecular testing. Majority were TR4 (31/47;65.97%) and TR5 (10/47;21.27%) (Table1). 23/47 (48.94%) showed no alteration. NRAS was the most common alteration (8 cases), followed by Copy Number Alterations (CNA) (6 cases) (Figure 1). Three TBS-III cases showed dual alterations (NRAS/CNA x2 and HRAS/CNA). Two TBS-IV cases had multiple alterations (EIF1AX/NRAS/TP53 and NRAS/PTEN).
Conclusion(s): While majority of thyroid nodules had a high TI-RADS score (TR4 or TR5), most cases fell into the atypical category (TBS III). Almost half of the thyroid nodules lacked any molecular alterations thereby suggesting an over-classification by TI-RADS. Further refinement of the TI-RADS criteria may be warranted. [Figure presented] [Figure presented]
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Objectives/UNASSIGNED:To evaluate whether non-small cell lung carcinoma (NSCLC) cytology specimens are reliable for programmed death-ligand 1 (PD-L1) immunohistochemical (IHC) testing. Methods/UNASSIGNED:Fifty-two cell blocks (CBs) with corresponding surgical pathology PD-L1 IHC testing were stained with a Dako PD-L1 pharmDX antibody (clone-22C3). Tumor cellularity was recorded as <100 or ≥100 cells. PD-L1 IHC was scored by percentage of tumor cells staining (<1%, ≥1%-49%, ≥50%) and compared between matched cases. Results/UNASSIGNED:Substantial agreement (κ = 0.63; 95% CI, 0.53-0.73) was reached between matched CB and surgical cases in CBs with ≥100 tumor cells compared to CBs with <100 tumor cells (slight agreement, κ = 0.19; 95% CI, 0.04-0.35). Overall, there was 67% agreement among paired cases (35/52 cases, κ = 0.51; 95% CI, 0.42-0.60). Conclusions/UNASSIGNED:CBs can be utilized for PD-L1 IHC testing, as illustrated by the 67% agreement between CB and surgical cases in our study. Disagreement is attributable to intratumoral heterogeneity and CB cellularity.

OBJECTIVE:Because of the indolent nature of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP) and potential requisite for conservative treatment, it is crucial to identify features of this entity pre-operatively. Our group recently published our findings that there are several cytomorphologic features that may be used as clues to distinguish NIFTP, PTC and follicular adenoma (FA) on fine-needle aspiration (FNA). Therefore, we aimed to determine the interobserver reproducibility of these findings. METHODS:Pre-surgical FNA slides from NIFTP (n=30), classic PTC (n=30) and FA (n=30) collected from 1/2013-8/2016 were reviewed by 7 cytopathologists blindly. Presence of selected cytomorphologic features was recorded and compared to determine percent agreement and inter-rater reliability among study cytopathologists using Gwet's AC1 statistics. RESULTS:For all the cytomorphologic features, the overall percent agreement amongst the pathologists ranged between 65.1% and 86.8% (Gwet's AC1 0.30 to 0.80). There was substantial or almost perfect agreement (Gwet's AC1 >0.60) in seven cytomorphologic features in the classic PTC group, in six features in the NIFTP group, and in five features in the FA group. There were no features with poor agreement (Gwet's AC1<0.0). CONCLUSIONS:The current study supports the reproducibility of our previous findings. The high level of agreement amongst pathologists for these groups, and particularly the NIFTP group, supports the notion that when viewed in combination as a cytologic profile, these cytomorphologic features may assist the cytopathologist in raising the possibility of NIFTP pre-operatively. This can potentially aid clinicians in deciding whether more conservative treatment may be appropriate.