Thyroid Hemiagenesis Accompanying an Ectopic Lingual Thyroid

Lingual thyroid is an uncommon condition and cases accompanying thyroid hemiagenesis are rarely documented. Patients with thyroid hemiagenesis are usually asymptomatic and generally diagnosed incidentally. Herein, we reported the case of thyroid hemiagenesis accompanying an ectopic lingual thyroid with euthyroidism and presented with regional symptoms.

Colloid nodular goitre associated with hemiagenesis of the thyroid gland

Hemiagenesis of the thyroid gland is a rare congenital abnormality usually left unnoticed without associated thyroid disorders. The most common congenital anomaly of the thyroid gland is a thyroglossal cyst, followed by ectopic thyroid tissue and thyroid dysgenesis, which may be agenesis or hemiagenesis. Preoperative underevaluation of the thyroid hemiagenesis (THA) associated with other thyroid disorders may cause intraoperative difficulty in identifying the gland and difficulty in preservation or even identification of major neurovascular structures during neck exploration. We report a patient who presented to us with right-sided neck swelling. On further evaluation and neck exploration, the patient was diagnosed with THA of the left lobe with right colloid goitre.

Parapharyngeal space ectopic thyroid with eutopic papillary thyroid cancer: A case report

BACKGROUND

Ectopic thyroid is a rare condition. Here we report an extremely rare case of parapharyngeal space ectopic thyroid, which has simultaneously found the papillary thyroid carcinoma of the eutopic thyroid.

CASE PRESENTATION

A 54-year-old woman was admitted to our hospital for a thyroid tumor and neck lymph nodes. CT and MR imaging revealed the presence of a thyroid right node, as well as a right parapharyngeal mass with a diameter of 2.5 × 2.3 cm. PET-CT was also performed to diagnose further, revealing that the suv metric of the PPS mass was 4.03. Considering that the mass was asymptomatic, we did not handle it at the first thyroid surgery. However, when the patient underwent a radioactive iodine scan before the radioactive iodine treatment, the imaging showed that the mass could intake the iodine. So, we arranged the second surgery for this mass, and the postoperative pathological examination confirmed the mass was well-differentiated thyroid tissue.

CONCLUSION

Parapharyngeal ectopic thyroid with eutopic thyroid cancer is extremely rare. Preoperative imaging examination can significantly avoid the missed diagnosis of this disease. Surgical resection is recommended for the ectopic thyroid while the eutopic thyroid is found to be malignant.

Robotic Resection of Ectopic Thyroid Tissue of the Mediastinum - Case Report and Literature Review

Introduction: Ectopic thyroid tissue (ETT) is a rare cause of mediastinal masses, representing less than 1% of all mediastinal tumors (1). ETT could be detected anywhere along the path of the first embryonic descent of the thyroid gland from the primordial foregut floor to its usual pre-tracheal position. ETT mediastinal localization accounts for fewer than 1% of all ectopic thyroid cases (2,3). Various surgical methods for approaching mediastinal masses have been documented in the literature, including median sternotomy, posterolateral thoracotomy, and, video-assisted thoracoscopic surgery (VATS) (4). More recently, robotic-assisted thoracoscopic surgery (RATS) has been proposed for these masses. The aim of this article is to present the use of robotic-assisted thoracoscopic surgery (RATS) for a rare case of a mediastinal ETT. Case presentation: We present the case of a 40-year-old male with no significant medical history who discovered a mediastinal mass on a thoracic CT scan following COVID-19 infection. Symptoms were dysphagia and anterior thoracic pain with cervical extension. Scintigraphy confirmed the presence of ectopic thyroid tissue in the mediastinum as well as a normal cervical thyroid gland. ETT was histologically confirmed by endoscopic ultrasound guided biopsy. Robotic assisted surgery was the chosen approach to surgically treat this mass and the technical details are presented. The mass was extracted through the cervical incision. Total surgical time was 230 minutes, and the blood loss was 60 ml. The patient was discharged after 48 hours with follow up showing a full recovery with no residual pain or respiratory symptoms. Conclusion: Ectopic thyroid tissue (ETT) is a rare cause of mediastinal masses, and the diagnosis is always a challenge. Robotic assisted thoracoscopic surgery was proved to be safe and efficient in this rare case of ETT developed in the superior mediastinum.

Accessory Thyroid Tissue Detected Using 131 I SPECT/CT Imaging

ABSTRACT

Thyroid ectopia has been described as a rare congenital anomaly, characterized by the presence of a thyroid gland in locations other than the orthotopic pretracheal location. The prevalence of accessory thyroid tissue in patients undergoing postablative radioiodine therapy in a 12-month period at a tertiary hospital nuclear medicine department was assessed. Fifty-seven patients were treated between September 2020 and September 2021. Retrospective analysis identified the presence and location of all accessory thyroid tissue separate from the orthotopic pretracheal thyroid gland. Accessory thyroid tissue was present in 21.1% (12/57) of the patients. Accessory thyroid tissue was most commonly located in the lingual region.

Thyroid Scintigraphy of a Rare Case of Left Thyroid Lobe Hemiagenesis With Subacute Thyroiditis

ABSTRACT

Thyroid hemiagenesis is a rare developmental anomaly. Patients with thyroid hemiagenesis have higher incidence of coexisting thyroid disorders in the remaining lobe. We present a rare case of a 21-year-old woman with subclinical hyperthyroidism incidentally found to have thyroid hemiagenesis on thyroid 123I-Na scan, which is confirmed on thyroid ultrasound. On scintigraphy, only the right lobe showed activity. Thyroid ultrasound demonstrated that the right lobe was normal without any nodule. The left lobe was not visualized. This patient's thyroid uptake and scan also revealed low uptake in the remaining right thyroid lobe in keeping with subacute thyroiditis.

Papillary Thyroid Carcinoma in Ectopic Thyroid Tissue Within a Suspected Cervical Paraganglioma

ABSTRACT

Ectopic differentiated thyroid carcinoma represents less than 1% of all thyroid carcinoma cases, which usually arises along the cervical midline, and (delving into literature) there are scarce reports of such entity in nuclear medicine imaging studies. We present a rare case of a confirmed synchronous, orthotopic, and heterotopic (in lateral ectopic thyroid tissue) differentiated thyroid carcinoma in a patient who was previously misdiagnosed as having a cervical paraganglioma, based on compatible clinical, analytical, and imagenological (both structural and functional) findings.

Hypothyroidism following sistrunk procedure: Thyroglossal duct cyst or ectopic thyroid?

Thyroglossal duct cyst is the most common cause of anterior midline neck swelling in children, but ectopic thyroid is an important but rare differential diagnosis. Establishing the orthotopic thyroid gland status is crucial as inadvertent removal of a lone functioning ectopic thyroid tissue in young children could lead to fluttering of growth and development if not identified early. We report the case of a 2 years 10-month-old boy who had Sistrunk's procedure for 'thyroglossal duct cyst': Diagnosed using USS, defaulted follow-up and presented subsequently with growth retardation from hypothyroidism.

An Unusual Posterior Mediastinal Mass - Ectopic Thyroid within the Oesophagus

Presence of ectopic thyroid tissue in unusual locations is a rare phenomenon. Herein we present the case of a 55 year old lady, who on evaluation of dyspnoea was detected to have a mediastinal mass. Initial radiological evaluation showed the presence of a mass arising from the wall of the oesophagus which was presumed most likely to be leiomyosarcoma. She underwent surgical resection of the mass, but on histopathological examination, it turned out to be a nodular goiter which was lying within the smooth muscle layer of the oesophageal wall.

A rare presentation of ectopic thyroid gland at right axilla

The thyroid gland and its hormones play important roles in organ development and in the homeostatic control of physiological mechanisms in human beings. As a result of embryogenic descent of thyroid gland, it commonly resides along the midline - from tongue to mediastinum (90%). Ectopic thyroid gland is a rare occurrence, with extra-lingual ectopic thyroid gland being even rarer. Thus, there is a concern for malignant metastasis. Madam H, a 56-year-old healthy woman presented to the Hospital Sultanah Nora Ismail, Johor, Malaysia in April 2020 with an increasing size of right axilla mass and history of weight loss. She was having right axilla mass for the previous 7 years but only noticed the increase in size about 1 year ago. She has no other constitutional symptoms. A tru-cut biopsy performed demonstrated a benign ectopic thyroid tissue. Thyroid function test showed primary hypothyroidism. Serum Chromogranin A and other thyroid antibodies were within the normal value. Further radiological imaging showed the normal thyroid gland at neck, with no signs of distant malignancy. There was no other axillary, mediastinal or hilar lymph node enlargement. She was started on regular T. L Thyroxine 100mcg daily and given regular follow-up in endocrine clinic. Benign ectopic thyroid gland is an unusual finding. As such, follow up is needed with possibility of carcinomatous transformation such as papillary carcinoma should be considered.

Thyroid isthmus agenesis and its clinical significance in a large-scale multidetector CT-based study

OBJECTIVE

The purpose of this study was to estimate the incidence and clinical significance of thyroid isthmus agenesis based on multi-detector CT imaging in a large-scale study.

METHODS

Data from 1601 patients who underwent neck multi-detector CT at our institution from January 2015 to March 2016 were included in this retrospective study. The morphology of each patient's thyroid gland was evaluated. We classified thyroid isthmus agenesis into two subgroups according to the thickness of the medial margin: clear-cut type (>4 mm) or tapering-edge type (≤4 mm). Associated thyroid pathologies were also evaluated.

RESULTS

Thyroid isthmus agenesis was present in 69 patients (41 males, 28 females), and its incidence was 4.77%. Eleven patients (0.76%) had the clear-cut type and 58 patients (4.01%) had the tapering-edge type. Papillary thyroid carcinoma was diagnosed in 4 patients (5.7% of isthmus agenesis patients). A total of 7 patients underwent thyroid function testing during the course of this study; 1 of these patients presented with borderline hyperthyroidism, and the remaining 6 were in a euthyroid state. The clear-cut type showed a statistically significant narrow gap and a high incidence of pyramidal lobes compared to the tapering-edge type.

CONCLUSION

Thyroid isthmus agenesis is not a rare developmental anomaly of the thyroid gland on multi-detector CT. Based on the metastatic pathophysiology of differentiated thyroid cancer, more extended indications for lobectomy are expected in differentiated thyroid cancer patients with thyroid isthmus agenesis.

Multi-parametric Ultrasound Evaluation of Pediatric Thyroid Dyshormonogenesis

The aim of this study was to assess the diagnostic contribution of gray-scale ultrasonography, color Doppler, superb microvascular imaging and shear wave elastography in thyroid dyshormonogenesis (TD). From October 2017 to February 2018, the prospective study included 31 patients (13.6 y; 11-14 y) diagnosed with TD based on thyroid scintigraphy and perchlorate discharge tests and 40 healthy pediatric volunteers (12.8 y; 10-16 y). Median resistive indices (RIs), peak systolic and end-diastolic velocities, vascularity indices (VIs) via superb microvascular imaging and shear wave elastography parameters were evaluated. Median VI values were significantly higher and median RI values were significantly lower in the study group than the control group. No significant difference was found between shear wave elastography parameters of the TD and control group. VI was significantly correlated with median total thyroid gland volumes (p = 0.002, r = 0.28), medication dosage (p = 0.03, r = 0.48) and 2-h radioactive iodine uptake values (p = 0.008, r = 0.57). VI is a clinically significant and novel parameter useful for diagnosing TD.

Lymphnode metastasis of thyroid cancer misinterpreted as lateral aberrant thyroid 40 years before identification of primary tumor. Case report and review of the literature

The differential diagnosis between lateral ectopic thyroid tissue with orthotopic normal gland and metastatic thyroid carcinoma is challenging. Lateral cervical site is a very rare location for ectopic tissue since only a few cases have been reported. The peculiarity of this clinical case is the finding of a thyroid carcinoma forty years after surgical resection of the ectopic thyroid lesion. This asynchronous association, never reported in literature, raises the question of the differential diagnosis between a true ectopic aberrant thyroid and an early lymph node metastasis from an occult thyroid carcinoma, evident in the primitive site many years later. Several elements, which will be matter of discussion, seem to favour the latter hypothesis. This case, although isolated, suggests that any lateral cervical mass, comprising thyroid tissue, should be regarded as a metastasis of thyroid carcinoma until proven otherwise. Carefull investigation of thyroid gland is mandatory.

Ectopic thyroids have lower computed tomography attenuation values than orthotopic thyroids

PURPOSE

To determine whether ectopic thyroid had the same computed tomography (CT) value as orthotopic thyroid.

METHODS

Twenty-one patients with 23 ectopic thyroids and 23 controls with orthotopic thyroids underwent CT scans and were included in this retrospective study. The CT images were reviewed in a blinded fashion by two radiologists. Independent-Samples T-test was used for comparison of CT attenuation values between two groups.

RESULTS

Ectopic thyroids had significantly lower non-enhanced attenuation (91.04 ± 5.97 Hounsfield Units vs. 106.56 ± 4.06 Hounsfield Units, P = 0.038) and contrast-enhanced attenuation (141.32 ± 6.42 Hounsfield Units vs. 169.82 ± 4.30 Hounsfield Units, P = 0.001) values than orthotopic thyroids.

CONCLUSIONS

Ectopic thyroids have lower CT attenuation values than orthotopic thyroids probably due to the structural or functional abnormalities. The dysgenesis and pathological changes of the ectopic thyroids may contribute to functional deficiency which finally leads to decrease of the CT attenuation values.

Sonographic diagnosis of coexisting ectopic thyroid and fourth branchial cleft cyst

Ectopic thyroid and fourth branchial cleft anomaly are rare congenital anomalies of the neck. This is a case report of the coexistence of these two rare congenital anomalies in a 1-year-old girl. She had ectopic lingual thyroid and asymptomatic abscess in the fourth branchial cleft cyst, which was found in ultrasonography carried out to evaluate congenital hypothyroidism. To the best of our knowledge, this is the first reported case of ectopic thyroid coexisting with fourth branchial cleft anomaly in the same patient.

Prevalence and sonographic features of ectopic thyroidal thymus in children: A retrospective analysis

PURPOSE

To assess the prevalence of ectopic thyroidal thymus tissue detected by sonography (US) in children and to analyze the US features.

METHODS

We retrospectively reviewed images of 216 children who had undergone a thyroid or neck US examination from February 2015 to June 2015. Lesions within or adjacent to the thyroid gland that showed echopatterns consistent with thymic tissue were diagnosed as ectopic thyroidal thymus tissue. Lesions were reviewed according to their side, location, level, size, shape, echo pattern, internal content, and vascularization.

RESULTS

A total of 216 children (119 girls, 97 boys) with a mean ± SD age of 8.6 ± 5.2 years were enrolled the study.Thirty children (13girls, 17 boys) (13.9%) had 35 lesions compatible with ectopic thyroidal thymus tissue.Nine children had intrathyroidal (4.2%) and 21 children had extrathyroidal (9.7%) ectopic thymus tissue.The mean ± SD ages of the children with and without ectopic thyroidal thymus tissue were 6.0 ± 3.6 years and 9.1 ± 5.2 years, respectively (P = .002). Twenty-five of the lesions were extrathyroidal and 10 were intrathyroidal. All extrathyroidal and most (8/9) intrathyroidal ectopic thymuses had fusiform shape with well demarcated contours. Ectopic thymuses were located either in the midportion (n = 23) or lower portion of the neck (n = 12). Both extrathyroidal and intrathyroidal ectopic thymuses showed typical hypoechoic (n = 22/25, n = 9/10, respectively) or hyperechoic (n = 3/25, n = 1/10, respectively) echo patterns with internal linear and punctate echoes.

CONCLUSIONS

Ectopic thyroidal thymic tissue is common in children. Radiologists should be vigilant about the unique US features of ectopic thyroidal thymus, including a hypo- and hyper-echoic echo pattern with multiple linear and punctate echoes, a fusiform shape, well-demarcated contours, and middle or low-lying location to differentiate it from other neck or thyroid lesions.

Mediastinal ectopic thyroid diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration: Report of three cases

An ectopic thyroid gland results from the abnormal migration of the thyroid in the course of its development. Primary ectopic mediastinal thyroid is very rare and occurs in less than 1% of all goiters that can be surgically excised. Ectopic thyroid tissue has a characteristic sonographic appearance as smooth-bordered, homogeneous, hypoechoic tissue with fine specular echoes. We report 3 cases of mediastinal ectopic thyroid diagnosed by endobronchial ultrasound-guided transbrochial needle aspiration biopsy.

The value of scintigraphy, computed tomography, magnetic resonance imaging, and single-photon emission computed tomography/computed tomography for the diagnosis of ectopic thyroid in the head and neck: A STROBE-compliant retrospective study

Because of its rarity, the exact imaging features of ectopic thyroid are poorly known.To analyze the value of scintigraphy, computed tomography (CT), magnetic resonance imaging (MRI), and single-photon emission computed tomography (SPECT)/CT in the diagnosis of ectopic thyroid in the head and neck.First, we retrospectively analyzed the scintigraphy, CT, MRI, and SPECT/CT images from 25 masses (22 patients) suspected of head and neck ectopic thyroid from 2006 to 2017 at the Shanghai Ninth People's Hospital. Each mass was imaged by nuclear imaging (scintigraphy with or without SPECT/CT) and radiological exam (CT and/or MRI). Pathological examination was considered as the gold standard. Secondly, thirteen malignant ectopic thyroids in the head and neck reported in the English literature from 2001 to 2017 were retrieved for comparison.The accuracy of scintigraphy was not significantly higher than that of CT (94.7%, vs 89.5%, P > .99) or MRI (92.3%, vs 84.6%, P > .99). Five masses which underwent scintigraphy with SPECT/CT were all true positive, while 1 was false negative on MRI, and 2 were false negative on CT. Compared to the benign ectopic thyroids in our study, the 13 malignant ectopic thyroids retrieved from the literature were grossly the same in shape, margins, and invasion on CT or MRI.The number of patients was limited, but scintigraphy combined with SPECT/CT could be a reliable method for the diagnosis of ectopic thyroid. Benign and malignant ectopic thyroids appear to be similar in shapes, margins, and invasion on CT or MRI.

An intracardiac accessory thyroid gland mimicking cardiac tumor: A case report and literature review

RATIONALE

An accessory thyroid gland (ATG) in the right ventricle is an extremely rare condition. Described herein are histological findings of ATG in the right ventricle found in a patient with a normal cervical thyroid gland.

PATIENT CONCERNS

A 53-year-old woman was referred to our hospital after experiencing intermittent precordial pain for 2 years.

DIAGNOSES

The mass in the right ventricle was diagnosed pathologically as ATG.

INTERVENTIONS

Complete excision was performed because of the patient's intermittent precordial pain and to exclude the possibility of malignancy.

OUTCOME

The patient's pain was resolved. No recurrence was observed during the 6-month follow-up.

LESSONS

After review and analysis of the case, we found that plain and contrast-enhanced computed tomography scans showed that the mass had a similar intensity and enhancement to a cervical thyroid gland, which we think may be a useful clue for making a preoperative diagnosis of ATG.

Thyroid Hemiagenesis: Incidence, Clinical Significance, and Genetic Background

CONTEXT

Thyroid hemiagenesis (THA) constitutes a rare, congenital disorder that is characterized by an absence of one thyroid lobe. Because the pathogenesis and clinical significance of this malformation remain undefined, specific clinical recommendations are lacking, especially for asymptomatic cases.

EVIDENCE ACQUISITION

The PubMed database was searched (years 1970 to 2017), and the following terms were used to retrieve the results: "thyroid hemiagenesis," "thyroid hemiaplasia," "one thyroid lobe agenesis," and "one thyroid lobe aplasia." Subsequently, reference sections of the retrieved articles were searched.

EVIDENCE SYNTHESIS

There is a noticeable susceptibility of subjects with THA to develop additional thyroid and nonthyroidal pathologies. In pathogenesis of concomitant thyroid pathologies, a chronic elevation in thyroid-stimulating hormone values may play an important role. Thus far, genetic studies failed to find a common genetic background of the anomaly, and the potential underlying cause was identified in a minority of the cases.

CONCLUSIONS

Patients with THA are prone to develop additional thyroid pathologies and theoretically might benefit from l-thyroxine treatment to lower the thyrotropin levels to those observed in the normal population. However, further research should be done to ascertain whether such intervention early in life would prevent development of associated thyroid conditions. At least, increased vigilance should be maintained to reveal all of the concomitant disorders as soon as possible during follow-up examinations. Application of high-throughput technologies enabling a genome-wide search for novel factors involved in thyroid embryogenesis might be the next step to expand the knowledge on THA pathogenesis.

Prevalence and Characterization of Thyroid Hemiagenesis in Japan: The Fukushima Health Management Survey

BACKGROUND

Thyroid hemiagenesis is a rare congenital variant characterized by the lack of development of one thyroid lobe with no clinical manifestations.

METHODS

This study was performed to determine the prevalence and characteristics of thyroid hemiagenesis in a normal Japanese population. This cross-sectional study was performed from October 9, 2011, to April 30, 2015. In total, 299,908 children and young adults in the Fukushima Health Management Survey were examined to determine the presence of thyroid agenesis or hemiagenesis. Thyroid width, thickness, and length were measured in 292,452 of these subjects.

RESULTS

Thyroid agenesis was diagnosed in 13 subjects, and hemiagenesis was detected in 67 subjects (0.02%; 22.3/100,000 individuals). Although there was no significant sex-related difference (p = 0.067), the female:male ratio was 1.67:1.00. Females were significantly dominant in right hemiagenesis, while there was no difference in left hemiagenesis between males and females. The thyroid volumes at the 2.5th and 97.5th percentiles for age and body surface area were determined for each sex. Multivariate regression analysis showed that a large hemithyroid volume was independently associated with the presence of contralateral hemiagenesis (p < 0.001).

CONCLUSION

The prevalence of thyroid hemiagenesis in the present study is in agreement with that reported in other countries. The prevalence of right hemiagenesis was higher in females, and the larger contralateral lobe in patients with rather than without hemiagenesis may have been caused by a compensatory feedback mechanism to prevent hypothyroidism. In addition, the prevalence of hemiagenesis, especially right hemiagenesis, may be affected by sex-related factors similar to those in patients with an ectopic thyroid gland.

Multiparametric ultrasonography and ultrasound elastography in the differentiation of parathyroid lesions from ectopic thyroid lesions or lymphadenopathies

To evaluate the accuracy of ultrasound elastography with Elastoscan^TM Core Index in the differential diagnosis of parathyroid lesions from ectopic thyroid nodules and lymph nodes. Seventy nine patients with repeatedly high levels of circulating intact parathyroid hormone, normal vitamin D and renal function tests, with an ultrasound scan showing a neck lesion, sharply demarcated from the thyroid lobules, were consecutively enrolled. Ultrasound with and without Color Doppler and ultrasound elastography were performed before histological examination. All ultrasound features, vascularization and ultrasound elastography diagnostic performance were assessed using ROC curves. Histological examination confirmed 47 parathyroid lesions, 18 thyroid ectopic nodules and 14 reactive lymph nodes. In distinguishing parathyroid from thyroid nodules, shape had a 100 % sensitivity (95 % CI 92.4-100) and 50 % specificity (95 % CI 37.2-64.7), cleavage had a 85.1 % sensitivity (95 % CI 72.3-92.6) and 77.8 % specificity (95 % CI 65.1-88) while peripheral vascularization had a sensitivity of 91.5 (95 % CI 79.6-97.6) and specificity of 72.2 (95 % CI 46.5-90.3). An Elastoscan^TM Core Indexof 1.28 was 46 % sensitive (95 % CI 33.4-58.7) and 77 % specific (95 % CI 66.2-89.1) in discriminating parathyroid lesions from thyroid nodules. An Elastoscan^TM Core Index of 1.0 was 78 % sensitive (95 % CI 65.1-88) and 71 % specific (95 % CI 56-81.3) in discriminating parathyroid lesions from lymph nodes (p = 0.045). An Elastoscan^TM Core Index greater than 2.58 had a 100 % sensitivity (95 % CI 43.8-100) and 95.4 % specificity (95 % CI 38.3-99.7) in discriminating malignant from benign parathyroid nodules. Elastoscan^TM Core Index was significantly higher in thyroid nodules than in reactive lymph nodes (1.18 ± 0.62, p = 0.008). The ultrasound features of cleavage and peripheral vascularization help to differentiate parathyroid from thyroid nodules. Elastoscan^TM Core Index can improve ultrasound discrimination of parathyroid lesions from lymph nodes. The Elastoscan^TM Core Index is significantly higher in malignant than in benign parathyroid lesions.

[Ectopic thyroid: the role of thyroid scan]

Ectopic thyroid is a rare malformative disease. We report an additional case of ectopic right thyroid lobe, detected during CT scan evaluation of a left lateral cervical mass.

Coexistence of resistance to thyroid hormone and ectopic thyroid: ten-year follow-up

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 hypothyroidism despite elevated FT3 and FT4 levels. Therefore the girl developed no defects in physical and cognitive development. Pituitary adenoma was excluded by magnetic resonance imaging. Ultrasonography did not find the thyroid gland in the normal place, while the thyroid scan found a large lingual thyroid gland. The octreotide inhibition test showed a reduction in thyrotropin by 41.98%. No mutation was detected in the thyroid hormone receptor (THR) β, THRα, thyrotropin receptor (TSHR), and GNAS1 genes. To our knowledge, it is an interesting RTH case coexisting with lingual thyroid.

Lingual Thyroid Ectopia: Diagnostic SPECT/CT Imaging and Radioactive Iodine Treatment

BACKGROUND

Lingual thyroid is a rare abnormality of thyroid development that is usually treated conservatively with levothyroxine replacement. Rarely, it becomes large enough to cause obstructive symptoms in the oral cavity, requiring definitive treatment.

PATIENT FINDINGS

This study reports on three patients with lingual thyroid treated with radioactive iodine-131 ((131)I) with successful radioablation of their ectopic thyroid tissues. Measurement of 24-hour radioactive iodine uptake within thyroidal tissues and hybrid single-photon emission computed tomography/computed tomography imaging using either iodine-123 or technetium-99m pertechnetate scans were performed in all patients demonstrating the location and size of lingual thyroid and absence of an orthotopic thyroid gland.

SUMMARY

The aim of this study was to describe nonsurgical management of obstructive lingual thyroid tissue with (131)I therapy for lingual thyroid radioablation. Patients were prepared with a low-iodine diet and levothyroxine withdrawal prior to radioablation for optimizing (131)I uptake in ectopic thyroid tissues. Hybrid single-photon emission computed tomography/computed tomography measurement of anatomic size of lingual thyroid tissue and radioactive iodine uptake guided the selection of therapeutic doses, resulting in administration of 10.7, 17.5, and 15.4 mCi of (131)I, respectively. There were no post-therapy complications, and clinical follow-up demonstrated resolution of obstructive oropharyngeal symptoms.

CONCLUSIONS

Ectopic lingual thyroid tissue is rarely associated with obstructive oropharyngeal symptoms due to progressive enlargement. Radioiodine therapy with (131)I is an effective treatment modality for ablation of ectopic thyroid tissue as an alternative to surgery.

Importance of ectopic thyroid tissue detected in the midline of the neck: single center experience

OBJECTIVE

Ectopic thyroid tissue (ETT) is a rare abnormality of the thyroid gland and the true prevalence and importance is not known. The aim of this study was to evaluate ultrasonography (US) guided fine needle aspiration biposy (FNAB) results, sonographic features, and frequency of ETT detected in the midline of the neck.

SUBJECTS AND METHODS

Five thousand five hundred and twenty outpatients who were referred to our thyroid clinic between September 2010 and April 2012 and underwent thyroid US, were retrospectively analyzed. Patients with ETT, detected in the midline of the neck in US were included in the study. Thyroid functions, sonographic features, and US guided FNAB results were evaluated.

RESULTS

There were 81 (81.8%) female and 18 (18.2%) male patients with a mean age of 50.9 ± 11.7. The ETT in the midline was present in 1.79% (99/5,520) of the patients. In the majority of the patients, benign sonographic features (isoechoic, regular margin, type 1 vascularization) were detected. There were 92 (92.9%) patients with a previous history of thyroidectomy and all were histopathologically benign. In 7 (7.1%) patients, there was no history of thyroid operation. FNAB results of ETT were benign.

CONCLUSION

This study evaluated the importance of ETT detected incidentally in the midline of the neck. Especially in patients with a history of thyroidectomy, the thyroid masses in the midline of the neck can be found as incidental with imaging methods. Our results suggests that the incidence of malignancy in this group is much lower than orthotopic thyroid nodules and they are often benign.

A case of pediatric ectopic thyroid in lateral lymph nodes

On average, ectopic thyroids are positioned in the embryotic decent path that emerges as a lingual thyroid or a thyroglossal duct cyst. It is uncommon for ectopic thyroids to be located in the lateral neck, which only represents 1%-3% of all cases. Any ectopic thyroids that emerge in the posterior lateral neck in pediatric patients should be regarded as an extremely unique case. We report a 13-year-old boy with ectopic thyroid tissue in the cervical lymph nodes with orthotopic euthyroid thyroid. The masses were located on the left posterior triangle area, which were confirmed as histologic benign thyroid tissue without any malignancy in the head and neck. Authors suggest that this case supports the benign lymphatic transport theory of lateral ectopic thyroid.

[Ectopic thyroid basi-lingual: A case report]

INTRODUCTION

The thyroid ectopic gland is a rare anomaly, especially when it’s a lingual thyroid. It is characterized by aspecific clinical presentation, causing a diagnostic problem. The diagnosis is based on a combination of imaging techniques as well as histological examination.

CASE PRESENTATION

We are presenting a case of a patient with thyroid basi-lingual treated surgically.

DISCUSSION

The low incidence of ectopic lingual thyroid , and their clinical variability requires radiological and isotopic investigations.

CONCLUSION

The diagnosis of this disease is primarily histological. The management of these ectopic thyroid is surgical.

Extreme phenotypic variability of thyroid dysgenesis in six new cases of congenital hypothyroidism due to PAX8 gene loss-of-function mutations

CONTEXT

Within the last two decades, heterozygous loss-of-function PAX8 mutations have been reported in patients with a wide degree of thyroid gland dysfunction and growth despite the presence of identical mutations.

OBJECTIVES

To search for PAX8 mutations in a cohort of patients with congenital hypothyroidism (CH) and various types of thyroid gland defects.

DESIGN

A cross-sectional study was conducted in a cohort of patients.

SETTING

The French neonatal screening program was used for recruiting patients.

PATIENTS

A total of 118 patients with CH, including 45 with familial and 73 with sporadic diseases, were included in this study. The thyroid gland was normal in 23 patients had hypoplasia, 25 had hemithyroid agenesis, 21 had athyreosis, and 21 had ectopy.

RESULTS

We found four different PAX8 mutations (p.R31C, p.R31H, p.R108X, and p.I47T) in ten patients (six patients with CH and four family members), two with sporadic and eight with familial diseases. Imaging studies performed in the index cases showed ectopic thyroid gland (n=2), hypoplasia (n=2), eutopic lobar asymmetry (n=1), and eutopic gland compatible with dyshormonogenesis (n=1). The previously reported p.R31C and the novel p.I47T PAX8 mutations are devoid of activity.

CONCLUSION

Four different PAX8 mutations were detected in six index patients with CH (ten total subjects). The p.R31C, p.R31H, and p.R108X mutations have been reported. The novel p.I47T PAX8 mutation presented loss of function leading to CH. Thyroid ectopy was observed in two cases of PAX8 (p.R31H) mutation, a finding that has not been reported previously. We observed a high inter-individual and intra-familial variability of the phenotype in PAX8 mutations, underlining that population genetic studies for CH should include patients with various clinical presentations.

Fetal thyroïdology

Advances in prenatal imaging techniques and in fetal hormonology now allow for identification of disorders of thyroid function in the fetus. These can potentially be treated in utero by giving drugs to the mother. This review shows the feasibility of in utero treatment of fetal thyroid disorders, either indirectly by treating the mother or by giving the necessary drugs directly to the fetus. For goitrous fetal hypothyroidism leading to hydramnios, repeated intra-amniotic injections of thyroxine have been reported to decrease the size of the fetal thyroid. Experience with such procedures is limited but positive. The risk that direct in utero treatment of the fetus may provoke premature labor or cause infection should be carefully evaluated. In women with Graves' disease, autoimmune fetal hyperthyroidism can generally be treated in a noninvasive way by optimizing treatment of the mother, such as by increasing the dose of antithyroid drugs. Follow-up of the efficacy and the possible long-term consequences of medical interventions to normalize thyroid function of the fetus are of great importance. Specialized care of the fetus should be provided by skilled teams with extensive experience in prenatal care.

The prevalence and features of thyroid pyramidal lobe, accessory thyroid, and ectopic thyroid as assessed by computed tomography: a multicenter study

BACKGROUND AND PURPOSE

Understanding the computed tomography (CT) characteristics of the pyramidal lobe and other thyroid variations and detecting them accurately using preoperative neck CT will minimize unnecessary remnant thyroid tissue after total thyroidectomy in patients with thyroid cancer. The purpose of the present study was to assess the frequency, location, and size of the pyramidal lobe and other thyroid variations using a large-scaled, multicenter study.

METHODS

Neck CT scans for 200 patients were selected from 11 institutions; a total of 2200 patients were included in the study. The patients underwent neck CT for the following reasons: trauma, known thyroid malignancy, cervical lymphadenopathy, palpable neck mass, oropharyngolaryngeal malignancy, vocal cord palsy, postchemotherapy CT follow-up, inflammatory or infectious neck lesion, parathyroid abnormality, and patient request. A single radiologist at each institution retrospectively analyzed 200 neck CT scans. Each radiologist investigated the presence, location, length, volume, and upper end of the pyramidal lobe and its separation or continuity with the main thyroid gland as well as the presence, location, length, and volume of the accessory or ectopic thyroid using a picture archiving and communication system.

RESULTS

A pyramidal lobe was present in 44.6% (981/2200) of the patients. The prevalence for the pyramidal lobe at the participating institutions ranged from 28.0% to 55.0% (mean, 44.6%). Pyramidal lobes originating from the left side of the thyroid were most common, and the number of pyramidal lobes showing separation from the main thyroid gland was 90 (9.2%). The mean anteroposterior diameter, transverse diameter, and length of the pyramidal lobe were 2.3, 5.9, and 20.8 mm, respectively. Among both men and women, the most common level of the upper end of the pyramidal lobes was the thyroid cartilage, but there was a significant difference in the frequency of the pyramidal lobe between males and females (p<0.0001). The rate of the pyramidal lobe detection in the 2-mm-slice-thickness group was higher than those in the 2.5- and 3-mm groups (p=0.0003).

CONCLUSION

Neck CT is useful for detecting the presence, size, configuration, and location of the pyramidal lobe and other thyroid variations.

Novel heterozygous thyrotropin receptor mutation presenting with neonatal hyperthyrotropinaemia, mild thyroid hypoplasia and absent uptake on radioisotope scan

Hyperthyrotropinaemia [mildly elevated thyrotropin (TSH) with normal thyroxine (T4) levels] demands a full assessment, including clinical examination, thyroid imaging and, where indicated, molecular genetic investigations. A male infant, both of whose parents were on T4 treatment, was referred at age 57 days with mild but persistent TSH elevation (12.7 mU/L) and normal free T4 (19.6 pmol/L), following notification by the screening laboratory of a capillary TSH of 10.7 mU/L (reference range, 1.7-9.1 mU/L) on day 8. Assessment showed a venous free T4 level of 15 pmol/L, venous TSH of 20.9 mU/L, serum thyroglobulin of 63 μg/L (reference range, <50 μg/L), and negative thyroglobulin and thyroid peroxidase antibodies. Thyroid ultrasound showed a eutopic, slightly small gland with heterogeneous texture; however, there was no uptake on radioisotope scan. Molecular genetic studies demonstrated a novel missense heterozygous mutation in the TSH receptor (TSHR) gene (c.1169G>T;p.Cys390Phe) in the child, mother and maternal grandmother, but not in the father. The infant was treated with T4 but this was discontinued at age 3 years when repeat testing showed a free T4 of 16.7 pmol/L (reference range, 9-23 pmol/L) and TSH of 8.5 mU/L (reference range, 0.3-5.5 mU/L). A heterozygous TSHR mutation should be considered in the context of hyperthyrotropinaemia and reduced/absent uptake on radioisotope scan. Detection of this mutation has allowed our patient to discontinue T4 treatment for the moment, with a view to staying off treatment in the long-term.

Dual ectopic thyroid with lingual and anterior hyoid ectopic thyroid tissue in a Chinese girl

Ectopic thyroid is not a common disease, and a double ectopic thyroid is extremely rare. We report a recent case of dual ectopic thyroid in an 11-year-old girl mimicking mono-ectopic lingual thyroid on the anterior view of the thyroid scan. The dual ectopic thyroid was shown on the lateral view, with foci in the lingual and anterior hyoid regions, but no thyroid tissue in the pre-tracheal region. She had originally been scheduled for surgery with a diagnosis of neck schwannoma, however, pre-operative thyroid scan and CT scan of the neck revealed the presence of dual ectopic thyroid tissue. Thyroid scan, and either CT, or ultrasonography should be performed routinely in cases presenting with a neck mass to avoid unnecessary misdiagnosis.

A high prevalence of dual thyroid ectopy in congenital hypothyroidism: evidence for insufficient signaling gradients during embryonic thyroid migration or for the polyclonal nature of the thyroid gland?

BACKGROUND

Thyroid ectopy results from the failure of the thyroid precursor cells to migrate from the primordial pharynx to the anterior part of the neck. Most ectopic thyroids are revealed by congenital hypothyroidism and present as a single round mass at the base of the tongue, with no other thyroid tissue. However, some cases have dual ectopy, with part of the tissue having partially migrated. We hypothesized that this occurs more frequently than previously reported.

METHODS

To determine the prevalence of dual ectopy, we reviewed the pertechnetate scintigraphies of 81 patients with congenital hypothyroidism from thyroid ectopy diagnosed between 2002 and 2011 at our institution.

RESULTS

We report a series of seven cases (9%) of dual ectopy, representing an incidence ranging from 1:50,000 to 1:70,000.

CONCLUSIONS

Almost one in 10 cases with congenital hypothyroidism due to thyroid ectopy has dual ectopy. This suggests that two populations of cells diverged at an early stage of development, which may arise from insufficient signaling gradients in surrounding tissues during early organogenesis or may indirectly support the polyclonal nature of the thyroid.

Pitfalls in the diagnosis of thyroid dysgenesis by thyroid ultrasonography and scintigraphy

OBJECTIVES

We aimed to investigate the reliability of thyroid ultrasonography (US) and scintigraphy in determining the type of thyroid dysgenesis (TD).

METHODS

The study included 82 children (8.0±5.6 years) with a diagnosis of TD by thyroid scintigraphy with (99m)Tc and/or US. The patients were re-evaluated 6.0±5.1 years after the diagnosis. Thyroid US was performed in all cases, regardless of the previous US imaging. Scintigraphy images performed at the time of diagnoses (n=60) were re-evaluated during the study. Those who had no scintigraphy at the time of diagnosis (n=22) or had discordant findings with US (n=6) underwent a new scintigraphy.

RESULTS

Scintigraphies revealed no uptake in 37, ectopia in 35, and hypoplasia in 10 cases. The sensitivity vs specificity for US to detect athyreosis, ectopia, and hypoplasia at the time of initial diagnoses was 90.5 vs 47.8, 10 vs 100, and 100 vs 80.4% respectively. The sensitivity vs specificity for scintigraphy at the time of initial diagnoses was 96.2 vs 100, 92 vs 97.1, and 100 vs 96%, respectively, for each diagnosis. Re-scintigraphy at the time of the study led to a change in the initial diagnosis of 3/6 cases. Repeated US showed disappearance of previously reported hypoplastic thyroid tissues in eight patients.

CONCLUSION

US alone could not differentiate ectopia and athyreosis, whereas scintigraphy alone is also prone to mistakes in newborns and young ages. Dual thyroid imaging is important for precise structural definition of TD.

Ectopic thyroid tissue: anatomical, clinical, and surgical implications of a rare entity

Ectopic thyroid tissue is a rare entity resulting from developmental defects at early stages of thyroid gland embryogenesis, during its passage from the floor of the primitive foregut to its final pre-tracheal position. It is frequently found around the course of the thyroglossal duct or laterally in the neck, as well as in distant places such as the mediastinum and the subdiaphragmatic organs. Although most cases are asymptomatic, symptoms related to tumor size and its relationship with surrounding tissues may also appear. Any disease affecting the thyroid gland may also involve the ectopic thyroid, including malignancy. The clinician must distinguish between ectopic thyroid and metastatic deposits emerging from an orthotopic gland, as well as other benign or malignant masses. Thyroid scintigraphy plays the most important role in diagnosing ectopy, but ultrasonography contributes as well. In cases of symptomatic disease, surgery is the treatment of choice, followed by radioiodine ablation and levothyroxine suppression therapy in more refractory cases. This review provides current understanding about the wide clinical spectrum of this rare condition, also referring to optimal diagnostic approach, differential diagnosis, and management strategies.

Ectopic thyroid presenting as a submandibular mass

Although extremely rare, the presence of ectopic thyroid tissue in the submandibular region should be considered in the differential diagnosis of tissue masses in the cervical region. Diagnosis is confirmed by fine-needle aspiration biopsy and exclusion of malignancy should be confirmed by histopathologic analysis of the lesion. In general, surgery is the treatment of choice. A rare case of ectopic thyroid in the right submandibular region is reported; it was diagnosed after total thyroidectomy and successfully treated through surgery.

Thyroid function and morphology in subjects with microdeletion of chromosome 22q11 (del(22)(q11))

INTRODUCTION

Monoallelic microdeletion of chromosome 22q11 (22q11DS) is considered to be the commonest human microdeletion syndrome. Abnormalities of thyroid function are sporadically reported in this syndrome, but very few studies have specifically assessed this issue, and thyroid morphology has not been systematically studied.

DESIGN

To evaluate the prevalence of abnormalities of thyroid function and morphology in a cohort of paediatric and adult patients with 22q11DS.

METHODS

Thirty patients with 22q11DS (median age 9.7, range 1.5-43.9 years) were studied. In all subjects, serum free-T(3), free-T(4), TSH, thyroperoxidase, thyroglobulin, and TSHr auto-antibodies, as well as thyroid ultrasonographic data, were evaluated and compared with age- and sex-matched healthy control groups, for paediatric and adult patients.

RESULTS

Fourteen (46.6%) patients showed thyroid hypoplasia involving the entire gland. In all the patients, the volume of the left lobe of the thyroid was significantly reduced (P < 0.01). Among the subjects with thyroid hypoplasia, 10 out of 14 (71%) showed a concomitant heart malformation, a condition that was present in five (31%) of the subjects with a normal thyroid volume (P < 0.05). Seven (23.3%) cases of subclinical hypothyroidism and one (3.3%) case of overt hypothyroidism were identified. Three (10%) patients were positive for thyroid auto-antibodies. Of the patients with overt and subclinical hypothyroidism, five out of eight (62.5%) patients showed thyroid hypoplasia.

CONCLUSIONS

This study confirms the presence of alterations of thyroid function in 22q11DS, and also suggests a frequent occurrence of abnormalities in thyroid morphology in these subjects. Patients with 22q11DS should be monitored for thyroid function, and thyroid ultrasound screening should be considered, especially in those patients with changes in thyroid function or congenital heart malformations. The possible relationship between developmental abnormalities in the heart and the thyroid gland should be confirmed.

Increased risk of thyroid pathology in patients with thyroid hemiagenesis: results of a large cohort case-control study

OBJECTIVE

Thyroid hemiagenesis (THA) is an anomaly resulting from the developmental failure of one thyroid lobe. Etiopathogenesis, clinical significance, and management of patients in whom THA is diagnosed are still a matter of debate. The aim of the study is to provide the first systematic analysis of a large cohort of subjects with THA.

DESIGN

Forty patients with THA are described in comparison to a control group of 80 subjects with fully developed thyroid gland.

METHODS

Serum concentrations of thyrotropin (TSH), free thyroxine (FT(4)), free triiodothyronine (FT(3)), and thyroid autoantibodies were measured. In 37 patients, thyroid ultrasonography and Tc-99m thyroid scintiscan were performed, followed by fine-needle aspiration biopsy if indicated. The remaining archival three cases were diagnosed with the use of I-131 scintiscan under basal conditions and after TSH stimulation.

RESULTS

Patients with THA, while usually clinically euthyroid, presented with significantly higher levels of TSH and FT(3) as well as with higher FT(3)/FT(4) concentration in comparison to the control group. Furthermore, a higher incidence of associated functional, morphological, and autoimmune thyroid disorders in patients with THA was observed when compared to subjects with bilobate thyroid (P<0.05).

CONCLUSIONS

Our results revealed that individuals with THA are more likely to develop thyroid pathology. The observed high incidence of associated pathologies is presumably due to long-lasting TSH overstimulation. Therefore, THA diagnosis should be followed by systematic observation and adequate levothyroxine treatment in patients with elevated TSH level.

Prevalence of thyroid hemiagenesis in an asymptomatic schoolchildren population

BACKGROUND

Thyroid hemiagenesis is a rare congenital anomaly in which one lobe of thyroid gland fails to develop. Because variations of the prevalence of this anomaly have been reported, the aim of this study was to evaluate the prevalence rate of thyroid hemiagenesis in an apparently normal population from Northern Poland.

METHODS

Ultrasound examination of the thyroid gland was performed in 4004 unselected 7-15-year-old school-children from the seaside zone of Northern Poland.

RESULTS

Two cases of thyroid hemiagenesis were found, both being absence of the left lobe in two girls. Thyroid volumes, adjusted to body surface area, were within normal range; serum thyrotropin, free thyroxine, and free triiodothyronine were within normal limits. Physical examination, abdominal ultrasound, and echocardiography did not show extrathyroidal malformations. Thyroid ultrasound was normal in the girls, parents, and siblings.

CONCLUSIONS

The study showed a 0.05% prevalence of thyroid hemiagenesis in asymptomatic schoolchildren population from iodine-sufficient area of Northern Poland.

Clinical and epidemiological characteristics of thyroid hemiagenesis: ultrasound screening in patients with thyroid disease and normal population

Thyroid hemiagenesis is a rare form of thyroid dysgenesis, in which one thyroid lobe fails to develop. The true prevalence of this rare abnormality is about 0.05-0.2% in normal population. We aimed to determine prevalence of thyroid hemiagenesis in patients with various thyroid disorders and a normal population in a mild to moderate iodine-deficient area. The clinical and thyroid ultrasonography records of 4,833 patients who presented with various thyroid disorders were reviewed. In addition, ultrasonographic data of two large surveys carried out for the community screening of iodine status of children (n = 4,772) and thyroid disorders of adult subjects (n = 2,935) were analyzed. In patients with thyroid disorders, we found 12 cases with thyroid hemiagenesis (0.25%). Thyroid hemiagenesis was due to the agenesis of the left lobe in all cases. The underlying thyroid diseases were Hashimoto's thyroiditis (n = 4), euthyroid multinodular goiter (n = 4), and toxic adenoma (n = 1). Three subjects have no underlying thyroid disease. In ultrasonography screening of normal population, altogether, the absence of the left lobe was detected in only two cases, indicating a true prevalence of thyroid hemiagenesis of 0.025%. None of the reviewed patients had thyroid dysfunction. Our community-based data is in accordance with previous studies in terms of prevalence and male-to-female ratio.