BackgroundUltrasound has become the initial approach to evaluating thyroid nodules, facilitating the distinction between benign and malignant nodules based on composition, echogenicity, nodule border or margin, shape, the presence of calcifications, and nodule dimensions. The American College of Radiology (ACR) recommended the Thyroid Imaging Reporting and Data System (TI‐RADS) as a classification system to standardize thyroid ultrasound reports and to predict the probability of malignancy in thyroid nodules using a scoring system (TR1‐TR5) based on multiple ultrasound characteristics and nodule size. Fine‐needle aspiration (FNA) is recommended as the next step for nodules that warrant further workup. The authors assessed the accuracy of the ACR TI‐RADS based on the corresponding FNA cytology results (Bethesda system diagnoses I‐VI).MethodsACR TI‐RADS ultrasound reports and corresponding FNA cytology diagnoses from January 1, 2018 to August 30, 2018 were evaluated.ResultsFrom January 1, 2018 to August 30, 2018, 2306 thyroid ultrasound‐guided FNAs were performed at our institution. Of 2306 cases, 361 had ACR TI‐RADS reports available. The majority of FNAs were TR4 (180; 49.9%) or TR3 (108; 29.9%). No TR2 or TR3 nodules were associated with Bethesda category V or VI diagnoses. The majority of TR4 nodules (142 of 180; 78.9%) and TR5 nodules (42 of 65; 64.6%) exhibited benign (Bethesda category II) cytology. Fourteen TR5 cases (21.5%) had malignant (Bethesda category VI) cytology.ConclusionsAlthough there were no TR2 or TR3 malignant (Bethesda category VI) diagnoses, and there were only a few malignancies in the TR4 and TR5 categories, the current results reassert the notion that the ACR TI‐RADS scoring system shows at least some correlation between benign or malignant cytology diagnoses, as illustrated by the greater number of malignant cases in the higher ACR TI‐RADS categories.

BackgroundDifferentiating parathyroid from thyroid lesions can be difficult on fine‐needle aspiration (FNA) due to overlapping cytomorphologic features. While the traditional parathyroid hormone (PTH) assays can help in the distinction, these tests may be cumbersome, particularly when the lesion is unexpected clinically and a needle wash is not collected at the time of FNA. Therefore, we chose to investigate the application of immunohistochemical staining (IHC) with GATA 3 and thyroid transcription factor‐1 (TTF‐1) on air‐dried cytology smears to distinguish parathyroid and thyroid lesions.MethodsAir‐dried touch preparation (TP) slides were prepared from consecutively selected parathyroid and thyroid specimens. Thirteen FNA cases with the clinical concern for parathyroid lesions were also included in the study. IHC was performed on unstained and ultrafast Papanicolaou (UFP) stained air‐dried slides.ResultsOn TP slides, GATA 3 expression was observed in all cases of parathyroid origin but no immunoreactivity was present in thyroid lesions. TTF‐1 expression was observed in all cases of thyroid origin but not in parathyroid lesions. GATA 3 and TTF‐1 expression of 13 FNA cases were consistent with the clinical impression or concurrent PTH tests.ConclusionsIHC with GATA 3 and TTF‐1 on air‐dried cytology smears is a simple and effective way to differentiate parathyroid vs thyroid lesions on FNA. Air‐dried unstained and UFP‐stained slides perform equally well with IHC, but UFP‐stained slides provide the added benefit of morphologic evaluation and assessment of smear cellularity prior to IHC.

NIFTP cases most commonly displayed suspicious Afirma results and RAS mutations on ThyroSeq, lacking aggressive/BRAF-V600E-like mutations. While NIFTP remains a surgical entity, the lack of aggressive/BRAF-V600E-like mutations can aid in determining the extent of surgery.

Our study demonstrates that NIFTP, PTC, and FA display several distinguishing and overlapping sonographic and Doppler features. Sonographic features appear to complement cytology findings and may help raise pre-operative concern for NIFTP in the proper clinical setting, potentially leading to a more conservative management approach.

The results of the current study demonstrate that the self-clotting method is superior to the conventional needle wash method for FNA samples. Cancer Cytopathol 2018;126:190-9. © 2017 American Cancer Society.