Ahuja Kriti, Bhandari Tarun, Banait-Deshmane Swati, Crowe David R, Sonavane Sushilkumar K
Department of Radiology, University of Alabama in Birmingham, Birmingham, AL, USA.
Department of Internal Medicine, East Tennessee State University, Johnson City, TN, USA.
Radiol Case Rep. 2018 Jul 9;13(4):909-913. doi: 10.1016/j.radcr.2018.06.004. eCollection 2018 Aug.
Ectopic thyroid gland is a developmental anomaly that results from the arrest of thyroid tissue along its path of descent from the floor of mouth to the pre tracheal position in the lower neck. It is typically found along the thyroglossal duct with the base of the tongue being the most common site. Apart from mediastinal extension of goiter, the incidence of true intrathoracic ectopic thyroid tissue is rare. Presence of ectopic thyroid has been reported not only in the chest but also in the abdomen and pelvis. Pericardial and intracardiac locations are extremely uncommon and right ventricle location is predominant among the described cases. We describe a case of incidentally detected ectopic thyroid tissue in a rarer location-adjacent to the left atrium. The patient, who had undergone a nephrectomy for renal oncocytoma 5 years ago, presented with unintentional weight loss and left sided flank pain, prompting a workup to rule out abdominal malignancy. Findings on the computed tomography (CT) scan of the abdomen and pelvis prompted further investigation including a chest CT which showed a heterogeneously enhancing mass near the left atrium. Given its location, further radiological investigations played an important role in eliminating the differential diagnosis of paraganglioma. The mass was surgically resected and discovered to be a hyperplastic thyroid nodule on histologic examination.
异位甲状腺是一种发育异常，是由于甲状腺组织在从口腔底部向下颈部气管前位置下降的过程中停滞所致。它通常沿着甲状舌管发现，最常见的部位是舌根。除了甲状腺肿的纵隔延伸外，真正的胸内异位甲状腺组织的发生率很低。异位甲状腺不仅在胸部被报道，在腹部和盆腔也有报道。心包和心内位置极其罕见，在所描述的病例中，右心室位置占主导。我们描述了一例在罕见位置——左心房附近偶然发现的异位甲状腺组织病例。该患者5年前因肾嗜酸细胞瘤接受了肾切除术，出现了非故意体重减轻和左侧胁腹疼痛，促使进行检查以排除腹部恶性肿瘤。腹部和盆腔计算机断层扫描（CT）的结果促使进一步检查，包括胸部CT，显示左心房附近有一个不均匀强化的肿块。鉴于其位置，进一步的放射学检查在排除副神经节瘤的鉴别诊断中起了重要作用。该肿块经手术切除，组织学检查发现是一个增生性甲状腺结节。
