Ectopic Thyroid Research Articles (Page 1)

Disclosure: N. Dhir: None. A. Safdar: None. M. Cillo: None.Introduction: Papillary thyroid cancer (PTC) is a common thyroid malignancy, which usually presents with the detection of a thyroid nodule on physical exam or imaging. It can metastasize to lymph nodes or other sites. PTC found in lymph nodes without a primary tumor in the thyroid gland is a rare occurrence. This can be distinguished from metastatic PTC by the absence of the primary tumor in the thyroid gland and the presence of thyroid tissue within the lymph node. Case Presentation: A 38-year-old woman with no significant past medical history presented to the clinic for a non-tender right submandibular mass. She noticed it 3 months prior to her visit and it has increased in size. Head and neck ultrasound revealed a complex cystic structure measuring up to 4.5 cm in the right side of the neck without any evidence of cervical lymphadenopathy. CT scan of neck showed no thyroid nodules but confirmed a complex right neck level IIa mass/lymph node with an enhancing solid component and thin wall cystic component. A dedicated thyroid ultrasound did not reveal any evidence of discrete thyroid nodules. Fine needle aspiration of the mass showed concerns for PTC, which was confirmed on the excisional biopsy revealing metastatic cystic PTC, 2.5 cm in largest dimension, without extranodal extension (1/7 lymph nodes were positive), and positive BRAF V600E mutation. The differential diagnosis included primary thyroid cancer that spread to this lateral lymph node versus ectopic thyroid cancer. Although ectopic thyroid cancer is a rare presentation, given the possibility she had a primary thyroid cancer that then spread to the lateral node, her risk of recurrence was deemed not to be insignificant. After shared decision making, she was recommended to proceed with total thyroidectomy with central and right sided lymph node dissection with adjuvant radioactive iodine therapy. She has yet to follow up on this recommendation and will likely prefer observation. Discussion: Ectopic PTC in a lymph node involves cancerous papillary thyroid cells arising from ectopic thyroid tissue within a lymph node. During embryogenesis, thyroid tissue could be displaced due to disrupted migration. There have been reports of ectopic thyroid tissue being found in the kidney, pancreas, lungs, and heart. The carcinoma could develop in the ectopic thyroid tissue, whether in a lymph node, the mediastinum, or even lungs, while the thyroid itself is normal. This is a rare and difficult to diagnose phenomenon. It is important to diagnose the source with appropriate imaging and careful histopathological and immunohistochemical analyses. Differentiating ectopic PTC from metastatic PTC is vital in providing an appropriate treatment plan and prognosis. This case highlights the importance of confirming the primary origin of PTC to further direct management.Presentation: Monday, July 14, 2025

Disclosure: S. Vallejo: None. J. Shakil: None. S. Dowlatshahi: None.Introduction: Maintaining euthyroid status is crucial for skeletal health, as elevated thyroid hormones accelerate bone loss, leading to decreased bone mineral density (BMD) and increased fracture risk. While most individuals tolerate high iodine intake, excessive iodine can induce thyrotoxicosis in susceptible individuals. Common sources include iodized salt, amiodarone, and seaweed-based supplements such as kelp. We report a case of iodine-induced thyrotoxicosis secondary to kelp consumption, resulting in severe osteoporosis, emphasizing the importance of dietary awareness in thyroid management. Case: A 58-year-old woman with osteoporosis, low BMI, and premature ovarian insufficiency (POI) was evaluated for worsening bone density despite prior treatment with alendronate. Initial BMD revealed the lowest T-score of -2.6. Laboratory evaluation showed: TSH <0.005 mIU/L, FT4: 7.14 ng/dL. FT3: 6.1 pg/dL, Calcium: 10.5 mg/dL, Albumin: 4.1 g/dL, PTH: 21 pg/mL. She had no thyroid disease history or relevant medication use. Physical exam was unremarkable. A whole-body I-123 scan showed decreased thyroid uptake, suggesting subacute thyroiditis. She was advised to avoid excessive iodine and was treated with prednisone. She also started denosumab but was lost to follow-up. Two years later, she presented with tremors, palpitations, and persistent thyrotoxicosis: FT4: 5.34 ng/dL, FT3: 7.0 pg/dL, TSH: <0.005 mIU/L, TSI: <0.10 IU/L, TRAb: <1.10 IU/L, Thyroglobulin: 5.4 ng/mL. Ultrasound showed an atrophic thyroid gland. A Tc-99m pertechnetate scan ruled out increased uptake or ectopic thyroid tissue. A repeat BMD showed worsening osteoporosis (T-score -3.0).Dietary history revealed substantial kelp supplement use, indicating chronic iodine excess. While POI contributes to osteoporosis, her worsening BMD corresponded with persistent thyrotoxicosis, suggesting iodine-induced thyrotoxicosis as the primary factor. Nutritional counseling and psychiatric assessment were recommended to evaluate behavioral factors contributing to excessive supplement use. Discussion: Excess iodine can overwhelm thyroid adaptation (Jod-Basedow effect), causing thyrotoxicosis, particularly in susceptible individuals. Beyond cardiovascular effects, prolonged thyrotoxicosis accelerates bone loss, exacerbating osteoporosis. Kelp and similar supplements can exceed the recommended iodine intake of 1,100 mcg/day, necessitating dietary education.This case highlights the difficulty of managing iodine-induced thyrotoxicosis, especially when unrecognized supplement intake is involved. Comprehensive care should include dietary counseling and, when needed, psychiatric evaluation to address behavioral patterns contributing to excessive supplement use and related health risks.Presentation: Monday, July 14, 2025

Disclosure: V.E. Bravo: None. J.B. Aragon: None.Lingual thyroid is a rare condition resulting from the failure of thyroid tissue to migrate to its normal location during embryologic development, often presenting as ectopic thyroid tissue at the base of the tongue. It is typically asymptomatic but may cause symptoms such as dysphagia, dysphonia, and dyspnea, especially if the ectopic tissue enlarges. This case report presents a 31-year-old Filipino female with a painless submental mass that had increased in size over two years. Initially misdiagnosed as a thyroglossal duct cyst, imaging revealed a 3.8 x 4.1 x 4.0 cm hyperdense mass at the tongue base, with no thyroid gland in its normal location. Thyroid function tests were normal, and fine needle aspiration biopsy confirmed the diagnosis of lingual thyroid.Lingual thyroid is seen predominantly in females and is more common in patients of Asian descent. While most cases are asymptomatic, hypothyroidism is noted in approximately 70% of individuals, requiring thyroid function tests to guide management. Imaging modalities such as ultrasound and CT scan help identify ectopic thyroid tissue, and a biopsy provides definitive diagnosis. In this case, a thyroid scintigraphy scan was not performed due to financial constraints, but the workup was sufficient for diagnosis.Management depends on the presence of symptoms and thyroid function. As this patient was euthyroid and asymptomatic, conservative management with regular follow-up was recommended. Surgical excision may be indicated for symptomatic patients or those with suspected malignancy. This case emphasizes the importance of considering lingual thyroid in the differential diagnosis of neck masses and highlights the role of imaging, thyroid function testing, and biopsy in establishing the diagnosis. Regular monitoring is advised for asymptomatic, euthyroid patients.Presentation: Monday, July 14, 2025

Disclosure: A. Dowlatshahi: None. U. Khan: None. L.M. Cobos: None.Background: Anaplastic thyroid cancer is an aggressive thyroid malignancy, with 5-year survival rate of <10% and mean survival time of 6 months after diagnosis with roughly 40% of patients having distant metastases at time of diagnosis. Surgery and radiation typically improve survival though prognosis is poor.1 We discuss a rare case of papillary thyroid carcinoma with anaplastic transformation with roughly 6 year survival.Clinical Case: A 62 year-old Hispanic female came to the ED after 10-months of left neck mass and dysphagia. Biopsy revealed 6 positive lymph nodes with imaging revealing a 4cm mass, a 1.7cm left thyroid nodule, and 1cm centrally calcified nodule concerning for malignancy. FNA Biopsy initially showed atypia of unknown significance however, repeated FNA revealed a benign left thyroid nodule, papillary thyroid cancer at 80% of tumor volume with an additional 20% attributed to anaplastic thyroid; she was diagnosed with papillary thyroid cancer with focal anaplastic transformation arising from ectopic thyroid tissue with positive BRAF mutation.PET CT in September 2018 demonstrated focal sigmoid colon uptake along with a 3mm RUL lung nodule. Repeat CT scans did not redemonstrate any colonic findings. The patient underwent bilateral neck dissection, total thyroidectomy, and parathyroid autotransplant in September 2018 followed by radiation therapy in October 2018. She briefly received chemotherapy with paclitaxel and carboplatin in November 2018 with RAI and anti-BRAF regimen of dabrafenib and trametinib from January to April 2019 which was discontinued for intolerance. Regular imaging and lab studies showed no recurrence of disease. The patient continues with follow-up almost 6 years from diagnosis on thyroid hormone suppression with levothyroxine.Conclusion: This case demonstrates an atypical course of anaplastic thyroid cancer. The patient had good response to surgery and chemoradiation and continues to fare well on thyroid hormone suppression almost 6 years from diagnosis, a very rare prognosis.Of note, the sigmoid colon uptake positive on initial PET CT disappeared on repeat imaging studies. It is unclear if the sigmoid colon uptake had been a false positive result or had resolved with treatment. It is important to note that the atypia of unknown significance on initial biopsy with benign features may have obscured the true diagnosis of papillary and anaplastic thyroid cancers in the absence of further investigation. This represents a case of significant deviation from present understanding of thyroid malignancy.

Ectopic thyroid tissue results from the embryonic failure of the thyroid gland to descend along the thyroglossal duct, resulting in the presence of thyroid tissue in an abnormal location. One of the most common locations where ectopic thyroid tissue (ETT) is found is at the base of the tongue, referred to as a lingual thyroid, having an estimated prevalence of 1 out of 100,000 to 300,000 in healthy individuals. We present the case of a 15-year-old female with a progressively enlarging mass at the base of her tongue, associated with dysphagia and sleep apnoea. Hormonal tests revealed hypothyroidism. Adopting a transoral approach, total resection was performed via electrocautery. Histopathology report revealed squamous lined tissue exhibiting mucous gland, confirming the diagnosis of ectopic lingual thyroid. The patient was started on thyroxine maintenance therapy and showed significant improvement. Keywords: Ectopic thyroid, lingual thyroid, hypothyroidism.

Ectopic Thyroid Carcinoma Presenting as a Superior Mediastinal Cystic Mass

Triple-Site Ectopic Thyroid Involving the Submandibular, Lingual, and Infrahyoid Regions: A Rare Case

Persistent Graves' disease (GD) after total thyroidectomy is sporadic and may be explained by incomplete total thyroidectomy, GD in ectopic thyroid tissue (ETT) or struma ovarii. We present a novel case of ectopic GD in a giant paracardiac mass, including an in-depth histologic exam. We searched the PubMed database on GD in ETT. A 34-year-old woman presented with severe thyrotoxicosis, 4 months after total thyroidectomy, and 6 weeks after cessation of levothyroxine substitution. Persistently high thyrotropin receptor antibodies (TSH-R-Ab) (27 IU/L, normal: <1.5 IU/L) and thyroglobulin >5,000 μg/L (normal: <77 μg/L) suggested GD in ETT. A 99mTc-pertechnetate SPECT/CT scan showed uptake in a paracardiac mass. After surgical removal of the 13 cm paracardiac mass, euthyroidism was achieved. Histology was typically remarkable for a Graves' pattern in the ETT, as opposed to a nodular pattern in the eutopic thyroid. The additional scoping review encompasses 29 reported ETT cases, of which only 11 were in the mediastinum. Graves' eye disease was present in 11/29 subjects. This is the first report showing a markedly different histology between the thyroid and the ectopic tissue. Persistent systemic severe GD post-thyroidectomy led to the detection of a giant paracardiac ectopic thyroid. GD in ETT is rare and presents a diagnostic challenge.

Ectopic Thyroid Tissues masquerading as a carotid body mass: Report of a case with literature review

Molecular and clinical characteristics of pediatric patients with primary congenital hypothyroidism: novel genetic variants and the genotype-phenotype association.

Congenital hypothyroidism (CH) is a leading preventable cause of neurocognitive impairment. Its incidence appears to be rising in several countries. We analysed 27 years of newborn-screening data (1997-2023) from the largest Chilean screening centre, covering 3,225,216 newborns (51.1% of national births), to characterise temporal trends and potential drivers of CH incidence. Annual CH incidence was modelled with Prais-Winsten regression to correct for first-order autocorrelation; additional models assessed trends in gestational age, sex, biochemical markers, and aetiological subtypes. We identified 1550 CH cases, giving a mean incidence of 4.9 per 10,000 live births and a significant yearly increase of 0.067 per 10,000 (95 % CI 0.037-0.098; p < 0.001). Mild cases (confirmation TSH < 20 mU/L) rose (+0.89 percentage points per year; p = 0.002). The program's recall was low (0.05%). Over time, screening and diagnostic TSH values declined, total and free T4 concentrations rose, gestational age at diagnosis fell, and a shift from thyroid ectopy toward hypoplasia emerged; no regional differences were detected. The sustained increase in CH incidence, alongside falling TSH thresholds and growing detection of in situ glands, suggests enhanced recognition of milder disease. Ongoing surveillance should integrate environmental, iodine-nutrition, and genetic factors to clarify the causes of this trend.

Ectopic thyroid carcinoma is rare. We present an exceptionally rare case of primary retropharyngeal ectopic papillary thyroid carcinoma (PTC) coexisting with an orthotopic thyroid goiter, aiming to enhance clinical awareness of this condition and to emphasize the importance of comprehensive management of both the ectopic lesion and the orthotopic thyroid. Case report and literature review. A 29-year-old male with a 3-year history of pharyngeal foreign body sensation underwent laryngoscopy and noncontrast CT/MRI, revealing a 2.0 × 3.5 cm left retropharyngeal mass. The mass was confirmed as papillary carcinoma via transoral excision. Postoperative contrast-enhanced CT identified metastatic-level VI lymphadenopathy, prompting total thyroidectomy with central neck dissection. Histopathology verified ectopic PTC with central node metastasis (1/20 nodes). Orthotopic thyroid exhibited nodular goiter without malignancy. No recurrence was observed during 36 months of follow-up. This case highlights retropharyngeal ectopic PTC's diagnostic complexity in a patient with orthotopic thyroid gland. Management of ectopic thyroid carcinoma may be guided by thyroid carcinoma guidelines, given its rarity. Total thyroidectomy is recommended to exclude concurrent thyroid malignancy and enable thyroglobulin-based surveillance.

Thyroid gland ectopia is a rare condition occurring as a developmental anomaly during the embryonic period, when the thyroid primordium migrates. The prevalence of thyroid gland ectopia is 1 per 100 000–300 000 healthy individuals. Struma ovarii is a variant of thyroid gland ectopia, defined by the presence of thyroid tissue in the ovary. Cases of struma ovarii are very rare, and in the pediatric population they are even more rare than in adults. Only a few cases of struma ovarii in patients under 18 years have been described in the literature. Here, we present a clinical case of papillary thyroid cancer in ectopic thyroid tissue in a 13-year-old girl. The patient's parents gave their consent to the use of their child's data, including photographs, for research purposes and in publications. Surgery remains the main treatment option for all histological subtypes of thyroid cancer, however patients with distant metastasis are treated with radioactive iodine therapy. In this case, as adjuvant therapy, the patient received a combination of thyroidectomy and radioactive iodine therapy due to the presence of implantation metastases. Malignant transformation of ectopic thyroid tissue is extremely rare, and it may be difficult for a clinician to determine the best treatment option due to the lack of uniform treatment guidelines for this disease. This case report describes the clinical course of struma ovarii as well as an option for surgical treatment and adjuvant therapy for this disease.

ABSTRACT Hashimoto’s thyroiditis (HT) involving ectopic thyroid tissue (ETT) is an infrequent entity. A 34-year-old lady presented to the Department of Endocrinology with progressive neck swelling. She had undergone total thyroidectomy 8 years ago. She was initiated on levothyroxine after the surgery, which was subsequently discontinued by herself. On examination, a nodular swelling over the anterior aspect of the neck in the midline was present. Ultrasonography of the thyroid demonstrated a hypoechoic nodule measuring 3 cm × 1.4 cm with significant internal vascularity in the anterior aspect of the neck in the midline and right paramedian location, positioned superior to the thyroid cartilage. The thyroid bed was devoid of any thyroid tissue. Fine-needle aspiration cytology of the midline nodule in the neck demonstrated a polymorphous lymphocytic impingement and Hurthle cell changes in the lymphoid background, features consistent with HT (Bethesda category 2). As the thyroid stimulating hormone (TSH) was elevated (24.98 mIU/L), thyroxine replacement of 75 mcg was re-initiated for the patient at our center and later titrated to 100 mcg based on her rising TSH levels on subsequent follow-up. On titration of 100 mcg, she had TSH 0.005 mIU/L and T4 of 11.30 mcg/dL after 6 months. Subsequently, she had normalized TSH (0.496 mIU/L) with 88 mcg of levothyroxine. Even in the absence of the thyroid gland, thyroiditis can still occur in ETT, which may lead to confusing thyroid function test results. Strict compliance with thyroxine therapy will prevent further enlargement of the ectopically located thyroid in this scenario and will prevent the need for thyroidectomy.

Thoracic surgical approach for retrosternal ectopic thyroid tissue after cervical total thyroidectomy: Case Report and Review of literature.

Congenital hypothyroidism (CH) occurs in 1:2,000 to 1:4,000 newborns, is often asymptomatic at birth, due to transplacental passage of maternal thyroid hormones and some thyroid production by the infant. CH is classified into permanent and transient forms, thyroid dysgenesis accounts for 85% while dyshormonogenesis 10-15% cases. CH is diagnosed through newborn screening, confirmation by elevated serum thyroid stimulating hormone (TSH) and low T4 or free T4 levels. Thyroid radionuclide uptake, thyroid sonography, serum thyroglobulin, help identify the underlying cause, although treatment may begin prior to these tests. Early diagnosis and treatment are crucial for preventing developmental delays and ensuring optimal growth and development in affected infants.

Abstract Aim The primary aim is to report our 10-years’ clinical experience of TGDC at Aberdeen Royal Infirmary Hospital in terms of clinical assessment and management. Our Secondary aim is to determine any histological findings of TGDC concurrent carcinoma or misdiagnosis following excision. Method A retrospective review has been performed on all patients at our local institution with a pre-operative diagnosis of TGDC for a period of 10 years from January-2010 to January-2020. A total of 40 patients were included in this study (36 -histologically confirmed TGDC, 4 -TGDC misdiagnosis). Records were reviewed for demographics, clinical presentation, Intraoperative findings and intervention, postoperative complications, and period. Results Female predominance (58%) was observed. Change in size was the most observed feature (78%). Majority of cysts (64%) were midline and infrahyoid in position. US and TFTs were the investigation of choice (78% and 83% respectively). 92% have undergone Sistrunk procedure with the remaining (8%) undertaking simple cystectomy. Mean cyst size: 2.92cm. Majority of excised cysts were intact and single in number (64% and 89% respectively). No findings of TGDC concurrent malignancy were reported. Wound infection was the most reported post-operative complication. Overall recurrence rate: 11%. Mean post-operative stay: 1.5 days. Mean total follow-up: 37 weeks. Majority of misdiagnosed TGDC (50%) were benign ectopic thyroid tissue. Conclusions Our experience revealed variability in clinical presentation and pre-operative diagnosis amongst patients and the effectiveness of the Sistrunk procedure in reducing recurrence rate.

Endoscopic surgery is useful and helpful especially to access areas with limited visibility. The combination of this technique with innovative approaches could be the solution to improve quality of surgery and patients’ outcome. This study aimed to illustrate how Endoscopic-Assisted Transoral Approach (EATA) can be used to successfully remove specific extracranial tumors with defined characteristics. Eleven patients with extracranial tumors underwent surgical resection using an EATA between 2003 and 2025. All patients underwent clinical examination and fiberoptic laryngoscopy. Preoperative CT and/or MRI was performed in all cases. All patients were successfully treated utilizing an EATA. Histological examination revealed nine parapharyngiomas, comprising five pleomorphic adenomas, two schwannomas, one ectopic thyroid gland, one lipoma, one masticator space schwannoma, and one nasopharyngeal pleomorphic adenoma. No intra-operative nor peri-operatory complications were observed. The only long-term sequela observed was Horner’s syndrome in the two schwannomas originating from the parapharyngeal-carotid space. The mean hospital stay was 2.6 days, while the mean follow-up duration was 9.8 years. The EATA represents a valid surgical technique for the treatment of benign, encapsulated, and non-vascular parapharyngeal space (PPS) tumors exhibiting posterior displacement of major vessels. This approach may also prove beneficial for the management of other benign, encapsulated, and non-vascular tumors located in the nasopharynx and masticator space.

Thyroglossal duct cysts (TGDCs) are the most common congenital neck masses, frequently diagnosed in both pediatric and adult populations. Accurate preoperative diagnosis and imaging are essential for effective management. Ultrasound (US) and thyroid scintigraphy are the primary imaging modalities used in clinical practice. This systematic review evaluates the diagnostic utility of US and thyroid scintigraphy in the management of TGDCs, comparing their diagnostic performance and assessing whether a combined imaging approach improves patient care. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies assessing the diagnostic roles of US and thyroid scintigraphy in TGDCs were identified through comprehensive searches of PubMed, Web of Science, Scopus, and ScienceDirect, with the final search conducted on May 5, 2024. A total of 18 studies involving 823 patients met the inclusion criteria. The results consistently showed that ultrasound is the preferred imaging modality, offering noninvasive, radiation-free, and highly accurate diagnostic capabilities. Ultrasound confirmed TGDC diagnosis in 66.1% of cases across studies, with detailed anatomical imaging supporting preoperative planning. Thyroid scintigraphy, while useful in cases of suspected ectopic thyroid tissue, was less frequently employed and generally unnecessary when a normal thyroid was identified on ultrasound. The Sistrunk procedure remains the preferred surgical intervention, with preoperative US proving essential in planning. Ultrasound is the most effective and noninvasive imaging tool for diagnosing TGDCs and planning preoperative interventions. Thyroid scintigraphy should be reserved for selected cases in which ectopic thyroid tissue is suspected. The findings support the use of ultrasound as the primary imaging modality, with thyroid scanning playing a secondary and more selective role in the management of TGDC.

Effects of early-life F-53B exposure on thyroid function in juvenile rats: The role of the cAMP signaling pathway.