Copyright © 2022 The Author(s); Published by Nickan Research Institute. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Immunopathol Persa. 2022;x(x):e31350 Original Consistency analysis of ultrasound-guided fine- needle aspiration and histopathology results in thyroid nodules Amir Bahrami 1 ID , Soheila Valizadeh 1 ID , Nasser Aghamohammadzadeh 1 ID , Farzad Najafipour 1 ID , Monireh Halimi 2 ID , Reza Javad-Rashid 3 ID , Javad Jalili 4 ID , Jalil Houshyar 1* ID 1 Endocrine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran 2 Department of Pathology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran 3 Radiology Department, Medical Radiation Sciences Research Group, Imam Reza Hospital, Tabriz University of Medical Sciences, Tabriz, Iran 4 Radiology Department, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Immunopathologia Persa http www.immunopathol.com *Correspondence to Jalil Houshyar, Email: hoshyarj2@gmail.com, houshyar@tbzmed.ac.ir Received 1 January 2022 Accepted 28 Apr. 2022 Published online 28 May 2022 Keywords: Fine needle aspiration, Histopathology, Thyroid nodule, Ultrasound Introduction: Thyroid nodules are considered as a frequent clinical problem. The great majority of thyroid nodules are benign; however malignancy probability is predicted to be 5-10%. The inconsistency between ultrasonography and fine-needle aspiration (FNA) findings is one of important problems in management of thyroid nodules. Objectives: This study was designed to investigate the consistency of ultrasonography, FNA and histopathology findings in thyroid nodules. Patients and Methods: In this descriptive study, 93 patients who were candidate for thyroid surgery were included. Data on ultrasound-guided fine-needle aspiration of the thyroid and histopathologic results before and after surgery were considered. The Cramér’s V and Fisher’s exact tests were conducted for this study. Results: In patients whose ultrasound (US) results were low-suspicious, we observed a significant correlation between FNA and pathology results (Cramér’s V = 0.574, P = 0.037). However, relationship between FNA and pathology was not accessible among patients whose ultrasonography results were intermediate suspicious or high-suspicious due to insufficient number of samples. Conclusion: In our study, a significant correlation was observed between FNA and pathology results in low- suspicious nodules. Abstract Citation: Bahrami A, Valizadeh S, Aghamohammadzadeh N, Najafipour F, Halimi M, Javad-Rashid R, Jalili J, Houshyar J. Consistency analysis of ultrasound-guided fine- needle aspiration and histopathology results in thyroid nodules. Immunopathol Persa. 2022;x(x):e31350. DOI:10.34172/ ipp.2022.31350. Introduction Thyroid nodules are considered as discrete lessions in the thyroid gland which may or may not be palpable and radiology are distinct from thyroid parenchyma (1). The frequency of palpable thyroid nodule is higher among women and older patients in developing societies and iodine-decreasing intake (2,3). Based on the epidemiological data, the frequency of nodules varies in different discovery methods, 19% to 68% ultrasonography, 2%-6% (palpation) and 8%–65% (autopsy) (4,5). In recent years, the diagnosis of thyroid nodules was increased, which is largely due to more availability and widespread use of imaging methods such as ultrasonography to examine patients’ symptoms (6). Although most of the nodules are benign, the risk of thyroid cancer is estimated at 7%-15% in all cases. Moreover, different factors like family history, gender, age and history of radiation exposure are Key point Thyroid nodules are considered as a frequent clinical problem. The great majority of thyroid nodules are benign, however malignancy probability is predicted to be 5%-10%. Around 93 patients who were candidate for thyroid surgery were studied. Data on ultrasound-guided fine-needle aspiration of the thyroid and histopathologic results before and after surgery, were evaluated. Based on our findings, when a nodule is classified in low-suspicious category, a significant correlation was seen between fine-needle aspiration and pathology results. considered the clinical significance for nodules malignancy (7,8). Since 1966, thyroid ultrasound (US) has been conducted to confirm the presence of nodules and detect thyroid disorders at early stages. Ultrasonography findings can evaluate the shape, composition, margin and type of calcification of nodules (9,10). Nodules that need to be further examind based on imaging DOI:10.34172/ipp.2022.31350