Jeffery Hannah, Bosch Karen D, Brain Caroline, Kurzawinski Tom, Beale Tim, Kowa Xin-Ying, Aziz Tarek Abdel
Department of Endocrine Surgery, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, UK.
Department of Paediatric Endocrinology, Great Ormond Street Hospital, London, UK.
Eur J Pediatr. 2025 Apr 8;184(5):284. doi: 10.1007/s00431-025-06121-9.
Ectopic aberrant thymic tissue is most commonly found in the thyroid gland and is increasingly found incidentally due to the widespread use of ultrasound. Correct identification of this benign pathology on ultrasound can avoid the morbidity associated with fine needle aspiration (FNA) and anxiety associated with a possible cancer diagnosis. A case series of 21 children found to have likely intrathyroidal thymic tissue on ultrasound scan of the neck between 2013 and 2024 at the University College London Hospital. Twenty-one children aged between six months and ten years old, 52% male and 48% female. The scans were performed following referral for a neck lump or cervical lymphadenopathy (N = 15), sore throat/cough (N = 4), pre-thyroidectomy scan for a Multiple Endocrine Neoplasia 2 patient (N = 1), and post cystic hygroma excision routine scan (N = 1). These well-defined hypoechoic foci ranged in size from 3 to 14 mm and direct comparison to normal thymic tissue was possible in 19/21 (90%). Three patients (14%) went on to have FNA to rule out papillary thyroid cancer (PTC); other cases had interval scans at median six months to confirm stable appearances.
All patients in our study with intrathyroidal ectopic thymic tissue were younger than 10 years. We suggest a tailored management approach based on the age at presentation, presence of clear thymic tissue for comparison and past/family history. Given that it is unlikely for such tissue to be present in older children, an FNA would be recommended to exclude underlying thyroid cancer in children over 14 years.
• Intrathyroidal thymic tissue is a common variant that will be increasingly incidentally picked up on ultrasound scans in chlidren.
• We suggest separation of children with ectopic intrathyroidal thymic tissue into three groups based on age and the ability to compare directly with normal thymic tissue.
异位异常胸腺组织最常见于甲状腺，且由于超声的广泛应用，越来越多地被偶然发现。在超声上正确识别这种良性病变可避免与细针穿刺活检（FNA）相关的发病率以及与可能的癌症诊断相关的焦虑。这是一组病例，2013年至2024年期间在伦敦大学学院医院对21名儿童进行颈部超声扫描时发现可能存在甲状腺内胸腺组织。21名儿童年龄在6个月至10岁之间，男性占52%，女性占48%。扫描是在因颈部肿块或颈部淋巴结病（N = 15）、喉咙痛/咳嗽（N = 4）、对一名多发性内分泌腺瘤2型患者进行甲状腺切除术前扫描（N = 1）以及囊性水瘤切除术后常规扫描（N = 1）而转诊后进行的。这些边界清晰的低回声灶大小在3至14毫米之间，21例中有19例（90%）可直接与正常胸腺组织进行比较。3例患者（14%）接受了FNA以排除甲状腺乳头状癌（PTC）；其他病例在中位时间6个月时进行了间隔扫描以确认外观稳定。
我们研究中所有甲状腺内异位胸腺组织的患者年龄均小于10岁。我们建议根据就诊时的年龄、是否存在可比较的清晰胸腺组织以及既往/家族史采取量身定制的管理方法。鉴于较大儿童不太可能存在此类组织，对于14岁以上儿童，建议进行FNA以排除潜在的甲状腺癌。
• 甲状腺内胸腺组织是一种常见变异，在儿童超声扫描中会越来越多地被偶然发现。
• 我们建议根据年龄以及与正常胸腺组织直接比较的能力，将甲状腺内异位胸腺组织的儿童分为三组。
