Fine needle aspiration biopsy does not permit to distinguish between benign and malignant follicular thyroid lesions (category IV in the Bethesda Cytopathology System). Some reports have suggested an association between increased serum TSH levels and thyroid cancer, so the aim of this study was to investigate the association between TSH levels and malignancy in patients with follicular thyroid nodules. Therefore, we conducted a retrospective study of all subjects who underwent surgical treatment for Bethesda IV thyroid nodules in a single center (years 2012–2017). A total of 127 patients were analyzed, and malignancy was present in 38.6% of the patients. Using ROC analysis, the best TSH cut-off point to differentiate benign from malignant disease was 2.1 mU/l and the age cut-off with better sensitivity and specificity was 47 years. The proportion of subjects with TSH ≥ 2.1 mU/l was greater among subjects with cancer than in those with benign diseases (65.3 vs 44.9%, P = 0.029). The concurrence of both cut-off points (TSH ≥ 2.1 mU/l and age ≥ 47 years) showed a higher diagnostic accuracy than either of the two variables separately. Therefore, the present study supports an association between serum concentrations of TSH and risk of malignancy among subjects with Bethesda IV thyroid nodules. TSH levels could modify the diagnostic and therapeutic approach of patients with Bethesda IV nodules.

中文翻译：

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Bethesda IV 类甲状腺结节患者的 TSH 水平和恶性肿瘤风险。

细针抽吸活检无法区分良性和恶性滤泡性甲状腺病变（贝塞斯达细胞病理学系统中的 IV 类）。一些报告表明血清 TSH 水平升高与甲状腺癌之间存在关联，因此本研究的目的是调查滤泡性甲状腺结节患者的 TSH 水平与恶性肿瘤之间的关联。因此，我们对在单一中心（2012-2017 年）接受 Bethesda IV 甲状腺结节手术治疗的所有受试者进行了回顾性研究。总共分析了 127 名患者，其中 38.6% 的患者存在恶性肿瘤。使用ROC分析，区分良性和恶性疾病的最佳TSH截止点是2.1 mU/l，具有更好敏感性和特异性的年龄截止点是47岁。癌症受试者中 TSH ≥ 2.1 mU/l 的比例高于良性疾病受试者（65.3% vs 44.9%，P = 0.029）。两个截止点（TSH ≥ 2.1 mU/l 和年龄 ≥ 47 岁）同时出现比两个变量单独诊断的准确性更高。因此，本研究支持 Bethesda IV 甲状腺结节受试者血清 TSH 浓度与恶性肿瘤风险之间的关联。TSH 水平可以改变 Bethesda IV 结节患者的诊断和治疗方法。