A pregnant woman with an autonomously functioning thyroid nodule: a case report

Abstract

Background

The epidemiology and natural history of autonomously functioning thyroid nodules (AFTNs) have not been elucidated. Here we report the pregnant Japanese woman with an AFTN.

Case presentation

The patient was a 31-year-old woman who was hospitalized due to the placenta previa associated with threatened abortion at the 16 weeks of her third pregnancy. At her second pregnancy, she was euthyroid but had a single, 2.3 cm nodule on her right thyroid lobe. Her thyroid hormone level was trended increased with her pregnancy progression, and the thyrotoxic state was remained after delivery. Before her third pregnancy, her hyper-vascular nodule enlarged to 3.4 cm at regular monitoring. When she visited our hospital, she was at 16 weeks of pregnancy and had thyrotoxicosis with negative TSH-receptor antibody. She delivered a baby weighing 2615 g without hypothyroidism at 39 weeks of pregnancy by natural delivery. After delivery, a ^99mTc scintigram showed a hot spot in her right thyroid lobe. She was diagnosed with AFTN and treated with methimazole while nursing.

Conclusions

This case showed that hCG stimulation during pregnancy caused thyroid nodule enlargement and enhanced thyroid hormone production. The pregnancy could be the pathological stimulus and provides chance to diagnosis for AFTNs.

摘要

背景：自主功能甲状腺结节（AFTNs）的流行病学和自然病史尚不明确。在此我们对一例日本女性患有AFTNs合并妊娠做一病例报告。病例介绍：患者31岁女性, 第三次妊娠16周时因前置胎盘伴先兆流产入院治疗。在她第二次怀孕时, 在她的甲状腺右叶有一个2.3cm的单发结节, 但是她的甲状腺功能正常。甲状腺激素水平随妊娠进展呈上升趋势, 分娩后仍保持甲状腺毒症状态。在她第三次怀孕之前, 定期监测行超声检查时她的结节已经增长到3.4cm。当她再来医院就诊时, 已经妊娠16周了伴有甲状腺毒症, TRAb阴性。妊娠39周的时自然分娩了一体重2615g且没有甲状腺功能减退的婴儿。分娩后, ^99mTc显象图显示右侧甲状腺叶有一个热结节。被诊断为AFTN, 并在产褥期接受了甲基咪唑治疗。结论：妊娠期hCG的刺激可导致甲状腺结节增大, 且甲状腺激素分泌增多。妊娠可能是AFTNs的刺激因素, 为AFTNs的诊断提供了机会。

Keywords:

• Autonomously functioning
• thyroid
• nodule
• epidemiology
• pregnancy
• hyperthyroidism

Author contributions

MN was responsible for patient care. MN performed the data collection. MN wrote the initial draft of the manuscript. MY and TS contributed to critically reviewed the manuscript. KK assisted in the preparation of the manuscript. All authors approved the final version.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used during the current report available from the corresponding author on reasonable request.