Kabaalioğlu Adnan, Öztek Murat Alp, Kesimal Uğur, Çeken Kağan, Durmaz Emel, Apaydın Ali
Department of Radiology, Akdeniz University Hospital, Antalya, Turkey.
Med Ultrason. 2017 Apr 22;19(2):179-184. doi: 10.11152/mu-913.
Intrathyroidal ectopic thymus (IET) is being increasingly reported in the radiology literature. Most of the reports are of individual cases or small series and prevalence and natural course of the pathology is not well known. The purpose of this study is to establish the prevalence of IET in children and report long term follow-up results.
In 180 children who were examined by ultrasound (US) for other reasons, 7 patients were indentified with IET. Together with the other seven children who were already under follow-up for IET (diagnosed using US criteria), these 14 patients were followed up with US for 30 months. Size, shape, location, echotexture and internal echoes of the lesions were evaluated.
There were 16 lesions in 14 children. The most common appearance was a fusiform hypoechoic lesion, with punctate and linear internal echoes and well-defined but slightly irregular borders located posteriorly in the lower thirds of the thyroid. In follow-up, there were no changes in echotexture, shape or border. In 3 patients, the lesion became slightly smaller, in a 10-year-old boy slightly larger, and in an 11-year old boy the lesion disappeared. In a patient with bilateral lesions, one lesion slightly decreased in size.
IET in children may be more common than thought. Its growth reflects that of a normal thymus. Awareness of this entity is important in order not to misdiagnose them, especially as papillary cancer, and to prevent unnecessary interventions.
甲状腺内异位胸腺（IET）在放射学文献中的报道日益增多。大多数报告为个别病例或小系列病例，该病理的患病率和自然病程尚不清楚。本研究的目的是确定儿童IET的患病率并报告长期随访结果。
在因其他原因接受超声（US）检查的180名儿童中，7名患者被确诊为IET。连同另外7名已因IET接受随访（根据US标准诊断）的儿童，这14名患者接受了30个月的超声随访。评估病变的大小、形状、位置、回声纹理和内部回声。
14名儿童中有16个病变。最常见的表现是梭形低回声病变，内部有斑点状和线状回声，边界清晰但略不规则，位于甲状腺下三分之一的后部。在随访中，回声纹理、形状或边界没有变化。3例患者的病变略有缩小，1例10岁男孩的病变略有增大，1例11岁男孩的病变消失。在一名双侧病变患者中，一个病变的大小略有减小。
儿童IET可能比想象的更常见。其生长反映了正常胸腺的生长情况。认识到这一实体对于避免误诊，尤其是误诊为乳头状癌，并防止不必要的干预非常重要。
