Liu Liyuan, Yu Yang, Chen Lei, Zhang Yang, Lu Guizhi, Gao Ying, Zhang Junqing
Department of Endocrinology, Peking University First Hospital, Beijing, People's Republic of China.
Department of Ultrasound, Peking University First Hospital, Beijing, People's Republic of China.
Eur Thyroid J. 2022 May 24;11(3):e210144. doi: 10.1530/ETJ-21-0144.
Hashimoto's thyroiditis (HT) can be divided into IgG4 HT and non-IgG4 HT based on IgG4 and IgG immunohistochemical staining. In clinical practice, it is often necessary to identify diseases such as primary thyroid lymphoma (PTL) and IgG4 HT when a patient presents with a rapidly enlarged thyroid. The aim of our study was to uncover the differential points between the two diseases.
Clinical information from 19 IgG4 HT and 10 PTL patients was obtained from the patients' medical records, including age, sex, main clinical manifestation, thyroid functional status, the presence of serum anti-thyroid peroxidase antibodies, anti-thyroglobulin antibodies, and thyroid ultrasonography results. Thyroid sections from all patients were collected to detect IgG4 and IgG expression by immunohistochemical staining.
The IgG4 HT patients were significantly younger than those in the PTL group (39.68 ± 10.95 vs 66.20 ± 10.23 years, P < 0.001). There were no significant differences in the sex distribution or TgAb- or TPOAb-positive rates. The PTL group had a higher prevalence of clinical hypothyroidism than the IgG4 HT group (P = 0.016). In the PTL group, thyroid lesions were more likely to exhibit hypoechogenicity (6/6 vs 1/19, P < 0.001) on ultrasound images. In the PTL group, two patients met the immunohistochemical cut-off value of the criteria for IgG4 HT.
Simply relying on immunohistochemistry for IgG4 cannot diagnose IgG4 HT correctly when a patient presents with rapid thyroid enlargement. A combination of clinical and pathological analyses will help distinguish IgG4 HT from PTL which may be with abundant IgG4-positive plasma cells.
基于IgG4和IgG免疫组化染色，桥本甲状腺炎（HT）可分为IgG4 HT和非IgG4 HT。在临床实践中，当患者出现甲状腺迅速肿大时，常常需要鉴别原发性甲状腺淋巴瘤（PTL）和IgG4 HT等疾病。我们研究的目的是揭示这两种疾病的鉴别要点。
从19例IgG4 HT患者和10例PTL患者的病历中获取临床信息，包括年龄、性别、主要临床表现、甲状腺功能状态、血清抗甲状腺过氧化物酶抗体、抗甲状腺球蛋白抗体的存在情况以及甲状腺超声检查结果。收集所有患者的甲状腺切片，通过免疫组化染色检测IgG4和IgG表达。
IgG4 HT患者比PTL组患者明显年轻（39.68±10.95岁对66.20±10.23岁，P<0.001）。性别分布或TgAb或TPOAb阳性率无显著差异。PTL组临床甲状腺功能减退的患病率高于IgG4 HT组（P = 0.016）。在PTL组中，甲状腺病变在超声图像上更易表现为低回声（6/6对1/19，P<0.001）。在PTL组中，有2例患者符合IgG4 HT标准的免疫组化临界值。
当患者甲状腺迅速肿大时，单纯依靠IgG4免疫组化不能正确诊断IgG4 HT。临床和病理分析相结合将有助于区分IgG4 HT与可能有大量IgG4阳性浆细胞的PTL。
