Ectopic thyroid is a rare condition, and its location in the anterior mediastinum is even rarer, there having been only 5 reported cases in the past 30 years. Here, we describe 2 clinical cases and present a review of the literature regarding the etiology, embryology and clinical manifestations of ectopic thyroid.

BACKGROUND Congenital hypothyroidism from thyroid dysgenesis (CHTD) is predominantly a sporadic disease characterized by defects in the differentiation, migration or growth of thyroid tissue. Of these defects, incomplete migration resulting in ectopic thyroid tissue is the most common (up to 80%). Germinal mutations in the thyroid-related transcription factors NKX2.1, FOXE1, PAX-8, and NKX2.5 h...

To the Editor: We reported 2 cases of ectopic thyroid gland (ETG) masquerading as pituitary adenoma (PA). The first case was a 15‐year‐old boy with growth, and mental retardation whose height was 121 cm and weight was 44 kg on admission. Bone age development index was 40, while bone age showed 6–10 years old. Magnetic resonance imaging (MRI) revealed pituitary hyperplasia [Figure 1a]. Thyroid u...

Ectopic thyroid is a rare embryogenic anomaly that occurs during its migration from foramen caecum to its pretracheal position. An intracardiac ectopic location is even rarer and found most commonly in the right ventricular outflow tract in sporadic reports. While surgery in symptomatic patients seems appropriate, resection of non-neoplastic ectopic tissue remains a clinical equipoise. Its occu...

BACKGROUND Ectopic thyroid tissue very rarely occurs in the buccal region. Even more rarely encountered is the papillary carcinoma arising in the ectopic tissue. METHODS AND RESULTS We herein present a 78-year-old female patient admitted with a giant, buccal mass that developed within the previous 2 years. Physical examination revealed a vegetative mass on the left buccal region without any c...

Ectopic thyroid on the ascending aorta is extremely rare, and its radiologic characteristics have not been reported in the radiologic literature. A case of ectopic thyroid on the ascending aorta is reported, and its imaging characteristics on computed tomography are discussed.

Ectopic thyroid tissue in the adrenal gland (ETTAG) usually presents as a well-circumscribed cystic mass on a CT scan. However, the MRI features of ETTAG are incompletely understood. We report a case of ectopic thyroid tissue in the adrenal gland, which demonstrates findings similar to those of a pheochromocytoma on the MRI.

We report a very rare case of incidental intrapericardial thyroid in a papillary thyroid cancer patient. Post ablation scan revealed iodine-131 (131I) uptake in the mid-chest. Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) was performed and showed a 18F-FDG avid lesion between the right atrium and the ascending aorta, (which was) shown to be an ...

Ectopic intrathyroidal thymic tissue can form a mass lesion within the thyroid gland and has rarely been reported in children. We report a case of intrathyroidal thymus accompanied by an intrathyroidal parathyroid gland in a 29-year-old woman who visited our hospital due to right neck mass diagnosed as metastatic papillary carcinoma by aspiration cytology in an outside hospital. She had a histo...

Resistance to thyroid hormone (RTH) coexisting with ectopic thyroid is rare. Here we report a case of RTH with ectopic thyroid. A ten-year-old girl had been misdiagnosed as congenital hypothyroidism and treated with levothyroxine since she was born. Ten-year follow-up showed that the elevated thyrotropin was never suppressed by levothyroxine and no signs indicating hyperthyroidism or hypothyroi...