Ectopic Thyroid Research Articles

SAT487 A Case of Mistaken Identity: A Rare Presentation of Ectopic Thyroid Tissue

Abstract Disclosure: N. Doshi: None. R. Azimzade: None. A. Rajpal: None. Background: Ectopic thyroid tissue (ETT) lateral to the midline is very rare, and its presence at the carotid bifurcation is exceedingly unique. Paraganglioma is the most common primary tumor at the carotid bifurcation, often called a carotid body tumor. We hereby present a case of lateral ETT with radiological features similar to paraganglioma. Case Description: A 72-year-old female with history of GERD was referred to us for evaluation of a well-circumscribed, slightly tender left neck mass. She has had the mass for approximately 15 years with previous evaluation with ultrasound in Yemen, where she was told to undergo surgery to remove it. She did not pursue surgery at that time. She moved to the U.S. one year ago and was re-evaluated for the neck mass. On examination, a firm mass was noted on the left side of the neck, followed by an ultrasound which demonstrated a 4.5 cm mass at the left carotid bifurcation and an enlarged right thyroid lobe of the same echogenicity with no tissue in the left thyroid bed. She had no clinical symptoms suggesting of hypo or hyperthyroidism. Laboratory examination showed suppressed TSH with elevated T3 suggesting thyrotoxicosis. CT neck was obtained for further characterization of the left neck mass which showed a hyper-enhancing, lobular soft tissue mass at the carotid bifurcation extending from the mandible to the level of the thyroid isthmus, concerning for carotid body paraganglioma or schwannoma. An I-123 scan demonstrated 24% (increased) uptake in the right thyroid lobe and minimal uptake in the carotid bifurcation tissue. The patient is currently being treated medically for thyrotoxicosis. Based on its ultrasonographic appearance, mild uptake on the I-123 scan, and no clinical suggestion of paraganglioma, the left neck mass is presumed to be ETT and no surgical intervention is being pursued. It is possible that the right lobe is thyrotoxic, suppressing iodine uptake in the ectopic tissue. Conclusion: This case demonstrates a unique presentation of ETT in the left carotid bifurcation with a thyrotoxic right lobe. It is difficult to distinguish the precise composition of neck masses at the carotid bifurcation, which has important implications for management. Often, an official diagnosis of thyroid tissue is made with histopathology only after the mass is surgically excised. Most ETT is benign in nature, and many times it is the only thyroid tissue available, thus surgery is not indicated. It is especially difficult to distinguish between ETT and paraganglioma on imaging itself. Somatostatin receptor scintigraphy, Ga-68/PET scanning, or iodine uptake scan can be useful to distinguish ETT from paraganglioma. Despite its rarity, lateral ETT must be included in the differential diagnosis of carotid body paraganglioma. Presentation Date: Saturday, June 17, 2023

FRI504 Ectopic Hyperactive Mediastinal Thyroid Tissue: A Case Report

Abstract Disclosure: C. Dimech: None. G. Jaiswal: None. A. Bhargava: None. Ectopic thyroid tissue is usually located along the normal path of the caudal migration of thyroid tissue during embryonic life. Substernal goiters are thought to occur by either the enlargement of ectopic mediastinal thyroid tissue (primary mediastinal goiter) or abnormal extension of thyroid issue into the superior mediastinum (secondary mediastinal goiter). Typically these goiters remain asymptomatic, and rarely result in hyperthyroidism or local compression of the surrounding area. We report a case of an 89-year-old Caucasian female with history of a multinodular goiter status post right hemithyroidectomy, who initially presented for subclinical hyperthyroidism. Further evaluation revealed negative thyroid stimulating antibodies. A thyroid ultrasound demonstrated a surgically absent right lobe, with a small heterogenous left lobe. A nuclear medicine radioactive iodine uptake and scan showed hypermetabolic residual thyroid tissue with a large area of increased radiotracer uptake projecting over the right anterior chest, concerning for ectopic thyroid tissue. A subsequent chest CT without contrast revealed an approximately 5 centimeter partially calcified anterior mediastinal/retrosternal mass. Given the patient’s age and co-morbidities, a decision was made to treat the hyperthyroidism with methimazole and monitor the ectopic tissue for worsening symptoms of compression. In cases with severe compressive symptoms, or difficult to treat hyperthyroidism, a surgical option must be considered. Presentation: Friday, June 16, 2023

SAT542 TDC or Not TDC: Isolated Ectopic Papillary Carcinoma in the Midline Neck with a Benign Native Thyroid

Abstract Disclosure: M. Fasen: None. L. Kosmiski: None. Background: Thyroglossal duct carcinoma is a rare entity, occurring in about 1% of all thyroglossal duct cysts (TDC). Several cases have reported PTC within a thyroglossal duct cyst. Initially thought to be a TDC, we present an unusual case of a midline ectopic papillary thyroid carcinoma with absence of features characteristic of a TDC in the context of benign native thyroid tissue. Clinical Case: A 19 year old female presents to the clinic with a progressively growing midline neck mass over the past five years associated with mild dysphagia. Physical exam was notable for 2 x 2 cm mobile nontender midline mass. Neck ultrasound demonstrated a complex cystic lesion measuring 3.8 x 3.4 x 2.5 cm with partial calcification and mildly vascular. The thyroid itself had no nodules. She underwent a Sistrunk procedure with follow-up pathology revealing 1.6 cm classical PTC that extended into surrounding soft tissue and focal invasion into skeletal muscle without a definitive remnant thyroglossal duct lining despite cystic architecture. The differential included PTC completely replacing the thyroglossal duct cyst, PTC arising from ectopic thyroid tissue or metastatic PTC. Due to the unclear origin of the PTC, decision was made to perform total thyroidectomy. Pathology of the thyroid and four lymph nodes were negative for malignancy confirming a PTC origin from an extra-thyroidal remnant. The patient’s course was complicated by post-operative hypocalcemia resolved with calcitriol and calcium carbonate. She is pending discussion with endocrinology regarding adjuvant radioactive iodine. Conclusion: Thyroglossal duct carcinoma, most commonly papillary carcinoma, is a rare condition that should be considered in patients presenting with cystic midline neck masses. Sistrunk surgery should be performed in all cases for tumor removal. Thyroidectomy in individuals with normal thyroid can be considered due to the probability of concomitant intraglandular thyroid cancer and enables management with adjuvant radio-iodine if needed. In this particular case, PTC was found without evidence of a TDC and suggests PTC arose from ectopic thyroid tissue. Ectopic thyroid tissue can undergo malignant transformation along with the native thyroid gland. There are only a few other reports of isolated ectopic thyroid tissue malignancy with a benign thyroid gland. Presentation Date: Saturday, June 17, 2023

SAT533 The Case of an Ectopic Thyroid Twin

Abstract Disclosure: A. Abu Limon: None. S.A. Aldasouqi: Consulting Fee; Self; Abbott Laboratories. P. Kachhadia: None. S. Khan: None. Introduction: Ectopic thyroid tissue is a rare but known developmental abnormality during the descent of the thyroid tissue from the floor of the foregut to its final location Infront of the trachea. The most frequent ectopic locations are the base of the tongue and anywhere along the course of the thyroglossal duct. It is very rare to have an ectopic thyroid tissue located in the mediastinum. It’s even more rare when the patient still has an almost normal thyroid gland in its usual location in the neck, and both are sizable and functional. Case Presentation: We are reporting the case of a 38-Year-old African American Female, who was involved in a car accident with non-critical injuries to her neck and chest area. She underwent a contrasted CT scan of her neck and chest that showed an anterior mediastinal mass towards the right at the level of the great vessels and arch, right paratracheal location overall measuring 6.0 x 4.6 x 4.5 cm. She was seen by Cardiothoracic surgery group and underwent Mediastinoscopy that confirmed a large firm to hard mass just inferior to the innominate artery was firmly adherent to the trachea as well as surrounding structures. Multiple biopsies showed thyroid tissue with focal mild chronic inflammation, benign. No atypia or malignancy is noted. Then, she was referred to our clinic for further evaluation. When interviewed, the patient denies any compressive symptoms (Shortness of breath, palpitations, chest pain or dysphagia). The patient has no personal or family history of thyroid disorders, including no thyroid cancer history. She has no Goiter on exam and no Pemberton sign is elicited. Laboratory work up was unremarkable including normal thyroid functions. Neck Ultrasound confirmed presence of a thyroid gland in its expected location, with Right Lobe Measurement: 5.04 x 1.70 x 1.47 cm Vol: 6.02 ml and Left Lobe Measurement: 3.94 x 1.25 x 1.21 cm Vol: 2.87 ml. We were keen to explore this matter further and ordered a thyroid uptake scan with 0.97 uCi iodine-123, that showed a 24-hour normal uptake of 27.4% at the thyroid bed and a separate substernal and RT paratracheal location uptake. Discussion: This patient has supplementary ectopic thyroid tissue in her mediastinum along with a normal thyroid gland in her neck. From the literature review and search, This is a very rare occurrence. The discussion with the patient is about the specific concern of the malignant potential of this ectopic thyroid and if surgical intervention is needed. The probability of cancer on ectopic thyroid tissue is less than 1% and when it occurs papillary carcinoma is the most common histology. Our patient has benign biopsy results and no signs nor symptoms related to this ectopic thyroid gland. The final decision is to not undergo surgery, but rather, a follow up with CT scan in 6 months. Presentation Date: Saturday, June 17, 2023

THU674 Papillary Thyroid Carcinoma Presenting As A Benign Ectopic Thyroid Mass In The Anterior Mediastinum. A Case Report

Abstract Disclosure: M.V. David-santos: None. C. Narvacan-montano: None. Background: Ectopic Thyroid Tissue (ETT) is a rare developmental anomaly that is due to the failure of the thyroid gland to assume its position in front of the trachea. Ectopic Thyroid tissue in the mediastinum is very rare, with only a few cases reported in the literature. An incidental Papillary Thyroid Carcinoma presenting as a mediastinal mass that turns out to be benign ectopic thyroid cells is even rarer. Case: This is the case of a 33-year-old female who presented with sudden onset difficulty of breathing and chest heaviness. On workup, she was found to have an anterior mediastinal mass, which showed ectopic thyroid cells on biopsy. Further evaluation of the neck area revealed a 1.25 cm x 1 x 1.13 cm nodule on the thyroid gland which showed suspicious for Papillary Thyroid Carcinoma on Fine needle aspiration biopsy. The patient underwent Total Thyroidectomy and Excision of the Anterior Mediastinal Mass. The histopathologic report of the thyroid mass revealed a Conventional Unifocal Papillary Thyroid Carcinoma, while the excised tissues comprising the mediastinal mass were consistent with benign ectopic thyroid tissues with colloid goiter. Conclusion: The presence of the ectopic thyroid mass in the anterior mediastinum may be a potential area for metastasis. The final pathologic report nevertheless, categorizes this Papillary thyroid carcinoma as having a low risk of metastasis as per the American Thyroid Association Classification of 2015. Hence the conservative approach of Suppression therapy and active surveillance is the choice of management for this unusual case. Presentation: Thursday, June 15, 2023

SAT563 Follicular Thyroid Cancer Masquerading as Chest Wall Mass With an Aggressive Course

Abstract Disclosure: I. Goyal: None. E. Punni: None. L. Adhikari: None. Introduction:Follicular thyroid cancers (FTC) are more aggressive than papillary thyroid cancer and usually have more advanced tumor stage at the time of presentation. Musculoskeletal metastases are rare though, but when present can cause various complications like pathological fractures and nerve compression. Clinical case:A 75-year-old female was seen in orthopedics clinic for a left infraclavicular chest wall mass. MRI chest showed a large destructive mass invading the manubrium. Biopsy showed follicular cells consistent with ectopic thyroid tissue. CT neck/chest showed 2x1.8 cm right thyroid lobe nodule and left sternoclavicular joint metastasis. She underwent total thyroidectomy and resection of portions of manubrium, left clavicle and left 1st and 2nd rib. Pathology showed FTC in right thyroid lobe, measuring 2.6 cm in greatest dimension with angioinvasion, and FTC of manubrium, adjacent connective tissue and sternoclavicular joint and ribs, measuring 6.3 cm in greatest dimension. Pathological TNM staging was pT2N0M1. Her 6-week post-op thyroglobulin (Tg) level was 28.7 ng/mL (Beckman Coulter Immunometric Assay, reference value <0.1 athyrotic). She was started on levothyroxine supplementation to achieve a TSH <0.01 uIu/mL. She was subsequently treated with 200 mCi of radio-active iodine (RAI) as adjuvant therapy. Post-therapy whole body scan showed increased activity in the right strap muscle and iodine-avid osseous metastasis in right hemisacrum. She further received radiation therapy to neck and sternal regions, and the right sacroiliac joint. Following this, patient was monitored with serial Tg panel and neck ultrasound (US). Her initial post-op US neck showed a soft tissue fullness in right thyroidectomy bed, concerning for residual disease but this was no longer seen after 3 months. Her Tg level downtrended from 28.7 ng/mL to 12.6 ng/mL and further to 1.8 ng/mL at 1-year follow-up. However, her course was complicated by development of several oral ulcers resulting from high-dose RAI therapy which were treated symptomatically with hydration, topical analgesics and Listerine mouth washes. The patient reported ongoing bowel incontinence since her initial cancer diagnosis. MRI pelvis showed rim-enhancing 4.5cm lesion centered at right sacral ala and extending into adjacent S1/S2 neural foramina. She was re-referred for palliative radiation therapy.Conclusion:This case of FTC is unique due to its uncommon initial presentation. Skeletal metastases to sacrum resulted in bowel incontinence in our patient. When present, skeletal metastases need treatment with high-dose (200 mCi) RAI. RAI therapy can cause xerostomia, hypogeusia and sialadenitis due to reductions in salivary flow. Clinicians should be aware of the early and late-onset complications of RAI therapy, discuss these with the patient before therapy and manage the complications adequately if these occur. Presentation Date: Saturday, June 17, 2023

SAT539 Thyroid Cancer Presenting as Aspiration Pneumonia

Abstract Disclosure: S. Aslam: None. M. Asif: None. I. Nadeem: None. W.J. Khan: None. Background Goiter, most often, is first noticed as a visible neck mass; however, some patients may present with signs and symptoms of hypothyroidism, or hyperthyroidism. Retrosternal extension can cause compression of the trachea, esophagus, and jugular veins resulting in dysfunction of these viscera. CaseA 68-year-old male presented with SOB, and weakness for 5 days. He had SaO2 79% on room air requiring oxygen, RR 28/min, HR 78/min and Temp.101.6 F, BP 94/48 mmHg. The lung exam revealed bilateral rhonchi and coarse crypts. Minimal non-tender nodularity was noted on the thyroid palpation not previously noticed by the patient or his family. Chest x-ray showed bilateral airspace opacities. CT chest revealed a large upper mediastinal mass displacing the trachea and esophagus to the right, a nodule in the left lobe of thyroid, subcarinal and right hilar lymphadenopathy and bilateral dependent consolidative opacities suggesting aspiration pneumonia but no PE. A barium esophagogram showed a 7.5 cm mediastinal mass causing 50% narrowing and displacement of esophagus and compression with left sided deviation of trachea. A barium swallow study was done, and the patient was found to have aspiration with all administered food types due to an abnormal swallowing mechanism. The patient was advised NPO and placed on NG tube feeding to prevent further aspiration. The patient underwent bronchoscopy and EBUS from station 4 lymph node, the pathology of which did not show any malignant cells. However, due to high clinical suspicion of a malignant process, the patient underwent a CT-guided biopsy of the mediastinal mass that showed bland thyroid tissue. Ultrasound of thyroid revealed multiple right and left lobe nodules. TSH and free T4, and calcitonin were WNL. The patient's hypoxia and fever resolved after completion of the antibiotics including ceftriaxone and doxycycline and being nothing per oral within 7 days. Due to persistent dysphagia, he was placed on PEG tube feeding and discharged from the hospital to a nursing home. The patient underwent ultrasound-guided fine needle biopsy of 1 right-sided and 2 left-sided thyroid nodules that resulted as papillary thyroid cancer. He underwent a successful right-sided thoracotomy and removal of large sized thyroid mass. The patient is seeing endocrinology as an outpatient for radioactive iodine and hormone replacement therapy. Conclusion We treated a patient of follicular carcinoma who presented with extrathyroidal symptoms. Retrosternal or ectopic thyroid tumors can present as euthyroid state without obvious enlargement of the normal thyroid gland. A meticulous clinical evaluation should include the differential diagnosis of retrosternal goiter or ectopic thyroid with cancer when treating patients who preset with sign and symptoms concerning for mediastinal disease. Presentation Date: Saturday, June 17, 2023

Ectopic Thyroid Tissue in the Uterus Identified by Iodine-131 SPECT/CT.

Ectopic Thyroid Tissue in the Uterus Identified by Iodine-131 SPECT/CT.

An unusual ectopic thyroid tissue location & review of literature

Ectopic thyroid is well-known pathology for several decades. Many locations have been described. Nowadays, only three cases of skull base location have been described in literature. In our case, we reported a single case of a 39-year-old male presenting with a supra-sellar and suprachiasmatic location. He presented no clinical symptoms, no endocrine alteration on biology and no skull base invasion which make this case unique compared to actual literature. Such diagnosis should always be an exclusion diagnosis as secondary neoplastic should be first ruled out.

An Anaplastic Thyroid Carcinoma of the Giant-Cell Type from a Mediastinal Ectopic Thyroid Gland.

Anaplastic thyroid carcinoma is a rare, aggressive form of thyroid carcinoma with a mean survival of less than 6 months. Ectopic thyroid tissue can be present in the mediastinum due to faulty embryogenesis with improper descent. Primary thyroid malignancies may arise from this ectopic tissue. A 90-year-old male with a history of prostatic adenocarcinoma, hypothyroidism, and occupational and therapeutic exposure to radiation presented with a rash on his chest. A review of the dermatopathology and excised mediastinal specimen revealed rare papillary foci that tested positive for thyroid markers from a background of poorly differentiated components. Molecular analysis confirmed a BRAF V600E mutation in the specimen. The final diagnosis was anaplastic thyroid carcinoma of the giant-cell type. Given the atrophic cervical thyroid tissue in the patient's neck with no evidence of previous surgery, this carcinoma was believed to arise from ectopic mediastinal tissue associated with cutaneous and bony metastasis. In conclusion, anaplastic thyroid carcinoma is an aggressive and rare thyroid malignancy that can arise from ectopic thyroid tissue in the mediastinum and should be considered in the differential diagnosis of primary undifferentiated mediastinal malignancies with bony involvement.

Ectopic Location of Thyroid Tissue in the Area of the Temporomandibular Joint. Clinical Case Report.

Background: The atypical location of organs and tissues in the human body is an important topic and a serious medical problem. Ectopic thyroid tissue is a rare and not fully explored condition. Asymptomatic forms of ectopic thyroid tissue usually do not require special treatment. However, symptomatic patients require special attention. For any localizations, such ectopy may be the only thyroid tissue in the body or exist simultaneously with the normal thyroid gland and have an increased tendency to cancerous transformation. The presence of two or more foci of ectopic thyroid tissue is an even rarer anomaly. 
 Case Description: The article presents an overview of ectopically located thyroid goiter in the temporomandibular joint area and describes specific diagnostic and treatment approaches. 
 Conclusion: Ectopy of thyroid tissue into the lower jaw and associated joints is rare. Medical problems associated with this usually pose significant difficulties in diagnosis. The possibility of ectopy of hormone-active tissue in atypical locations should always be considered to avoid a pathological problem.

Investigation of the impact of nonsynonymous mutations on thyroid peroxidase dimer.

Congenital hypothyroidism is one of the most common preventable endocrine disorders associated with thyroid dysgenesis or dyshormonogenesis. Thyroid peroxidase (TPO) gene defect is mainly responsible for dyshormonogenesis; a defect in the thyroid hormone biosynthesis pathway. In Bangladesh, there is limited data regarding the genetic etiology of Congenital Hypothyroidism (CH). The present study investigates the impact of the detected mutations (p.Ala373Ser, and p.Thr725Pro) on the TPO dimer protein. We have performed sequential molecular docking of H2O2 and I- ligands with both monomers of TPO dimer to understand the iodination process in thyroid hormone biosynthesis. Understanding homodimer interactions at the atomic level is a critical challenge to elucidate their biological mechanisms of action. The docking results reveal that mutations in the dimer severely disrupt its catalytic interaction with essential ligands. Molecular dynamics simulation has been performed to validate the docking results, thus realizing the consequence of the mutation in the biological system's mimic. The dynamics results expose that mutations destabilize the TPO dimer protein. Finally, principal component analysis exhibits structural and energy profile discrepancies in wild-type and mutant dimers. The findings of this study highlight that the mutations in TPO protein can critically affect the dimer structure and loss of enzymatic activity is persistent. Other factors also might influence the hormone synthesis pathway, which is under investigation.

Lingual thyroid ectopia

The lingual thyroid gland is an abnormal mass of ectopic thyroid tissue visible at the base of the tongue, caused by an embryological anomaly in the development of the thyroid gland. Identification and symptom-adapted treatment of ectopia are important in preventing hypothyroidism and development of obstructive symptoms. Purpose. To present a case of lingual ectopia of the thyroid gland in a child with an incidentally diagnosed formation of the root of the tongue based on primary ultrasound diagnosis. Material and methods. A 7-year-old boy without clinical signs of hypothyroidism during a routine examination revealed a voluminous asymptomatic formation of the root of the tongue. Results. Along the midline at the root of the tongue there is a rounded, non-displaced, painless formation about 20 mm in diameter. Regional lymph nodes are not enlarged. The picture of ectopic thyroid tissue in the root of the tongue, in the absence of thyroid in a typical site on the neck. There is subclinical hypothyroidism with a TSH level of 12.8 mсME/mL (normal 0.6–4.84). The presence of ectopia was confirmed by scintigraphy with Technetium-99m pertechnetate. Normal TSH level of 3.37 mcME/mL and a reduction in the volume of ectopic thyroid tissue from 3.3 mL to 2.13 ml revealed 3 months after levothyroxine therapy at a dose of 50 mcg/day. Conclusion. Ultrasound exam with Doppler mapping is mandatory and allows not only to identify ectopic tissue, but also to identify the absence of thyroid in a typical anatomical area on the neck. The study of the hormonal profile and subsequent scintigraphy make it possible to make a final diagnosis, assess the function of the ectopic organ and determine the option of drug and/or surgical treatment.

Ultrasound diagnosis and treatment of branchial cleft cyst and preoperative management.

The ultrasonic diagnosis of cervical and facial cystic masses, as well as cases of missed diagnosis and misdiagnosis, was examined, to improve the diagnosis of branchial cleft anomalies. A retrospective analysis was conducted on 17 patients with branchial cleft cyst anomalies, including 11 males and 6 females, aged 12-53years, with an average age of 33 ± 2years, were unilateral single. All patients who underwent an ultrasound examination and image storage for retrospective analysis, and both longitudinal and transverse sections were scanned to observe the shape, size, boundary, peripheral relationship, and blood flow signal of the masses. All cases were examined with an enhanced CT scan, and pathological reports were generated. Among the 17 cases of branchial cleft anomalies, 15 cases were branchial cleft cysts, while one case involved fistula formation and one case involved sinus tract formation. Based on the type of branchial cleft, the first, second, and third cysts were classified in 4, 12, and 1 case, respectively. The sensitivity rate and specificity of ultrasonic diagnosis were 14/17 (82.4%) and 4/6 (66.7%), respectively. Ultrasonic characteristic analysis for the masses can be found in simple cystic masses or hypoechoic masses, most of them are of a regular shape and have a distinct boundary, and almost no blood flow signal. All patients who were misdiagnosed exhibited blood flow signals, including 1 patient with an abundant blood flow signal, 1 patient suspected of having ectopic thyroid with an abnormal function due to the rat-tail sign, 2 patients misdiagnosed as local inflammatory focus, and 1 patient misdiagnosed with tuberculous lymphadenitis. Ultrasound has a detection rate of up to 100% for cervical and facial masses, providing a fundamental determination of lesion characteristics and specific guidance for preoperative diagnosis. If the blood flow signals can be identified and carefully considered their peripheral relationship, the diagnostic rate can be improved.

Ectopic thyroid mass in mediastinum with normal thyroid function and location

There are very few cases of mediastinal ectopic thyroid reported in the literature. An asymptomatic 49-year-old woman with a mediastinal mass is the subject of this report. Mediastinal ectopic thyroids’ epidemiology, clinical manifestations, diagnosis, and treatment were also discussed. A mediastinal ectopic thyroid ought to be viewed as a differential finding among all mediastinal masses. Careful extraction is suggested for both the analysis and treatment of this condition in light of its true capacity for harm and pressure on mediastinal structures. The clinical significance of mediastinal ectopic thyroid is demonstrated in this case.

Camouflaged Asymptomatic Mediastinal Thyroid Ectopia in a Patient with Toxic Goiter: A Case Report

Camouflaged Asymptomatic Mediastinal Thyroid Ectopia in a Patient with Toxic Goiter: A Case Report

Ectopic thyroid cancer with a normal thyroid gland

Introduction: Ectopic thyroid tissue may appear in any location along the trajectory of the thyroglossal duct from the foramen cecum to the mediastinum, as either a lingual thyroid or a thyroglossal duct cyst. In rare cases, aberrant migration of the gland can result in lateral ectopic thyroid tissue. As for native thyroid gland, ectopic tissues are subject to malignant transformation. Case Report: A 40-year-old female patient presented with a right-sided neck swelling. She had a history of treated Hodgkin’s lymphoma at the age of 16 years. She has hypothyroidism and on thyroxine and is known to have benign small thyroid nodules for the last 7 years. The neck swelling was suspicious for papillary thyroid carcinoma upon cytological examination. She underwent surgery (total thyroidectomy with central and right lateral selective neck dissection) that confirmed the presence of papillary thyroid cancer in the neck but the thyroid gland was devoid of any cancer. The patient had post-operative radioiodine ablation. She is free of any recurrence or residual disease after one-year post-treatment. Conclusion: This case highlights the unusual presentation of thyroid carcinoma arising within an ectopic thyroid tissue in an otherwise cancer-free thyroid gland. The management of this case followed the standard treatment of metastatic thyroid cancer; however, it raises the question of whether these rare cases should receive de-escalation of standard management.

Molecular investigation of TSHR gene in Bangladeshi congenital hypothyroid patients.

The disorder of thyroid gland development or thyroid dysgenesis accounts for 80-85% of congenital hypothyroidism (CH) cases. Mutations in the TSHR gene are mostly associated with thyroid dysgenesis, and prevent or disrupt normal development of the gland. There is limited data available on the genetic spectrum of congenital hypothyroid children in Bangladesh. Thus, an understanding of the molecular aetiology of thyroid dysgenesis is a prerequisite. The aim of the study was to investigate the effect of mutations in the TSHR gene on the small molecule thyrogenic drug-binding site of the protein. We identified two nonsynonymous mutations (p.Ser508Leu, p.Glu727Asp) in the exon 10 of the TSHR gene in 21 patients with dysgenesis by sequencing-based analysis. Later, the TSHR368-764 protein was modeled by the I-TASSER server for wild-type and mutant structures. The model proteins were targeted by thyrogenic drugs, MS437 and MS438 to perceive the effect of mutations. The damaging effect in drug-protein complexes of mutants was explored by molecular docking and molecular dynamics simulations. The binding affinity of wild-type protein was much higher than the mutant cases for both of the drug ligands (MS437 and MS438). Molecular dynamics simulates the dynamic behavior of wild-type and mutant complexes. MS437-TSHR368-764MT2 and MS438-TSHR368-764MT1 showed stable conformations in biological environments. Finally, Principle Component Analysis revealed structural and energy profile discrepancies. TSHR368-764MT1 exhibited much more variations than TSHR368-764WT and TSHR368-764MT2, emphasizing a more damaging pattern in TSHR368-764MT1. This genetic study might be helpful to explore the mutational impact on drug binding sites of TSHR protein which is important for future drug design and selection for the treatment of congenital hypothyroid children with dysgenesis.

A 15-year-old Girl with a Lateral Neck Mass Turning Out to Be Papillary Thyroid Carcinoma-Lateral Ectopic Papillary Thyroid Carcinoma or Lymph Node Metastasis?

Lateral neck lesions in children are common and involve various infectious or inflammatory etiologies as well as embryological remnants such as branchial cleft cysts. Although unusual, ectopic thyroid tissue can also present as a lateral neck mass. Here, we present an unusual case of a 15-year-old girl treated for an asymptomatic lateral neck mass that after surgical removal was found to be papillary thyroid carcinoma (PTC). However, after removal of the thyroid gland, no primary thyroid tumor was found. The question arose whether the lateral neck lesion was a lymph node metastasis without identifiable primary tumor (at histological evaluation) or rather malignant degeneration of ectopic thyroid tissue. Total thyroidectomy was performed with postoperative adjuvant radioactive iodine ablation. Even though PTC in a lateral neck mass without a primary thyroid tumor has been described previously, pediatric cases have not been reported. In this report we share our experience on diagnosis, treatment and follow-up, and review the existing literature.

Extension of Multinodular Goiter to the Parapharyngeal Space - a Case Report.

parapharyngeal space can have a mass of thyroid origin following metastasis from the thyroid or ectopic thyroid tissue. The extension of multinodular goiter into the parapharyngeal space is rare. A 54-year-old female presented with a 5-month history of neck mass and dyspnea. On examination, a large mass was seen on the right side of the neck which was bulging into the right parapharngeal. In the sonography, a large 50 × 57mm cyst seen at the upper end of the right lobe of the thyroid. Computed tomography (CT) identified a 46 × 56mm lesion medial to the right carotid sheath with a mass effect on the parapharyngeal space from the posterolateral aspect and appeared to be an exophytic cystic nodule arising from the upper pole of the right thyroidal lobe. The patient underwent total thyroidectomy, and the final pathology of multinodular goiter was reported. The spread of masses of the thyroid origin to the parapharyngeal space should be considered one of the differential diagnoses of these space masses.