Azzam Eman Z, Salah Marwa A, Aboelwafa Waleed A, Essam Rawan M, Bondok Maha E
Internal Medicine, University of Alexandria, Alexandria, EGY.
Head and Neck Surgery, Alexandria University Teaching Hospital, Alexandria, EGY.
Cureus. 2024 Dec 30;16(12):e76615. doi: 10.7759/cureus.76615. eCollection 2024 Dec.
Thyroid nodules, based on high-resolution ultrasonography (HRUS), are among the most common endocrine abnormalities that affect the general population because of their high estimated prevalence rates. Fine needle aspiration cytology (FNAC) is a safe, cost-effective modality to differentiate between benign and malignant thyroid nodules based on the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), thus avoiding unnecessary surgery. However, categories III and IV of BSRTC remain a controversial issue in clinical practice, encompassing a wide range of risks of malignancy. Hence, our study aimed to assess the malignancy rates of thyroid nodules classified as Bethesda III and IV categories as evidenced by post-thyroidectomy histopathology; study the association between the American College of Radiologists Thyroid Image Reporting and Data System (ACR-TIRADS) score of these two categories and the postoperative histopathological analysis; and study the predictors of malignancy in these two categories.
A prospective study was conducted on 242 patients who underwent FNAC throughout the study from December 2022 to August 2023. All patients who performed FNAC were primarily subjected to history taking, clinical examination, thyroid-stimulating hormone (TSH), thyroid autoantibodies (antithyroglobulin (anti-TG) and thyroid peroxidase antibodies (TPO Abs)), and HRUS with a further categorization of thyroid nodules according to the ACR-TIRADS scoring system. The cytological aspirates were categorized according to the BSRTC. Patients with Bethesda III and IV categories were resorted to surgery according to clinical factors, sonographic features, and patients' preferences.
A total of 17 cases with Bethesda III and 65 patients with Bethesda IV were included. Seventy-one out of 82 patients (86.6%) underwent surgical intervention. The proportions of malignant nodules classified as TIRADS-2, TIRADS-3, TIRADS-4, and TIRADS-5 scores were 0.0, 4.5 (n=1/22), 22.7 (n=5/22), and 72.7% (n=16/22), respectively. The rate of malignancy was 18.2% (n=2/11) among class III and 33.3% (n=20/60) among class IV-categorized Bethesda thyroid nodules. In univariate logistic regression analysis, age ≥ 40 years, body mass index ≥ 30 kg/m², higher TSH, positive anti-TG antibodies, radiation exposure, irregular borders, marked hypoechogenicity, ill-defined margins, microcalcifications, solid consistency, taller than wide growth, solitary nodule, and nodule size > 2 cm, and suspicious lymph nodes were associated with higher malignancy risk. In multivariate regression analysis, positive anti-TG Abs, radiation exposure, irregular borders, taller-than-wide growth, hypoechogenicity, calcifications, and solid consistency remain to be independent predictors of malignancy.
The malignancy rates of Bethesda class III and IV nodules in this study met the estimated malignancy risk proposed by BSRTC. TIRADS scores 4 and 5 confer a higher risk of malignancy in Bethesda III and IV thyroid nodules. Positive thyroglobulin antibodies and radiation exposure are independent factors of malignancy in Bethesda III and IV nodules. Moreover, ultrasound features, including irregular borders, taller-than-wider growth, hypoechogenicity, calcifications, and solid consistency, are associated with increased malignancy risk and should be considered in the surgical selection of patients.
基于高分辨率超声（HRUS）的甲状腺结节是影响普通人群的最常见内分泌异常之一，因其估计患病率较高。细针穿刺细胞学检查（FNAC）是一种安全、经济有效的方法，可根据甲状腺细胞病理学报告贝塞斯达系统（BSRTC）区分良性和恶性甲状腺结节，从而避免不必要的手术。然而，BSRTC的III类和IV类在临床实践中仍然是一个有争议的问题，涵盖了广泛的恶性风险。因此，我们的研究旨在评估经甲状腺切除术后组织病理学证实的分类为贝塞斯达III类和IV类的甲状腺结节的恶性率；研究这两类结节的美国放射学会甲状腺影像报告和数据系统（ACR-TIRADS）评分与术后组织病理学分析之间的关联；以及研究这两类结节的恶性预测因素。
对2022年12月至2023年8月整个研究期间接受FNAC的242例患者进行了一项前瞻性研究。所有接受FNAC的患者首先进行病史采集、临床检查、促甲状腺激素（TSH）、甲状腺自身抗体（抗甲状腺球蛋白（抗-TG）和甲状腺过氧化物酶抗体（TPO Abs））以及HRUS检查，并根据ACR-TIRADS评分系统对甲状腺结节进行进一步分类。根据BSRTC对细胞抽吸物进行分类。根据临床因素、超声特征和患者偏好，将贝塞斯达III类和IV类患者进行手术。
共纳入17例贝塞斯达III类患者和65例贝塞斯达IV类患者。82例患者中有71例（86.6%）接受了手术干预。分类为TIRADS-2、TIRADS-3、TIRADS-4和TIRADS-5评分的恶性结节比例分别为0.0、4.5%（n = 1/22）、22.7%（n = 5/22）和72.7%（n = 16/22）。在贝塞斯达III类甲状腺结节中，恶性率为18.2%（n = 2/11），在IV类中为33.3%（n = 20/60）。在单因素逻辑回归分析中，年龄≥40岁、体重指数≥30 kg/m²、TSH升高、抗-TG抗体阳性、辐射暴露、边界不规则、显著低回声、边界不清、微钙化、实性质地、纵横比大于1、孤立结节、结节大小>2 cm以及可疑淋巴结与较高的恶性风险相关。在多因素回归分析中，抗-TG抗体阳性、辐射暴露、边界不规则、纵横比大于1、低回声、钙化和实性质地仍然是恶性的独立预测因素。
本研究中贝塞斯达III类和IV类结节的恶性率符合BSRTC提出的估计恶性风险。TIRADS评分4和5在贝塞斯达III类和IV类甲状腺结节中具有较高的恶性风险。甲状腺球蛋白抗体阳性和辐射暴露是贝塞斯达III类和IV类结节恶性的独立因素。此外，超声特征，包括边界不规则、纵横比大于1、低回声、钙化和实性质地，与恶性风险增加相关，在患者的手术选择中应予以考虑。
