Ectopic Thyroid Papillary Carcinoma with Cervical Lymph Node Metastasis as the Initial Presentation, Accompanied by Benign Thyroid Gland.

BACKGROUND: Ectopic thyroid papillary carcinoma presenting as bilateral neck lymph nodes metastasis is very rare. Ectopic thyroid tissue may appear in any location along the trajectory of the thyroglossal duct from the foramen cecum to the mediastinum. It is subject to malignant transformation and is classically accompanied by a similar transformation of the native thyroid gland. Similar to that of the native thyroid gland, the most common malignancy found is Papillary thyroid carcinoma. Unusual cases in which ectopic thyroid carcinoma presents with normal native tissue support an alternative hypothesis that ectopic thyroid tissue may develop malignancies independently from the native thyroid gland. OBJECTIVE: We present an extremely rare case of a 30-year-old woman previously diagnosed with Hashimoto's thyroiditis, presenting with a palpable mass in the lateral neck suspicious for malignancy. RESULTS: After several examinations and surgical removal of the mass, histopathologic evaluation of the continuous sections of the thyroid, demonstrated metastatic disease from papillary carcinoma of the thyroid. Total thyroidectomy and biopsy revealed benign thyroid tissue without any foci of microcarcinoma. A hypothesis of ectopic thyroid tissue and its malignant transformation was made. CONCLUSION: By presenting this case, our goal is to highlight and make the physicians aware of the possibility of developing primary carcinoma of the ectopic thyroid tissue, without an active tumor of the thyroid gland.

A case report of coexistence of ectopic lingual thyroid with hypoplastic normal thyroid gland.

Ectopic lingual thyroid along with a normally located thyroid gland is an uncommon condition caused by an aberrant descent of thyroid during embryogenesis. It is more common among females and expresses during puberty, pregnancy and menopause. It is mostly associated with hypothyroidism. Patient usually presents with complaints of dysphagia, dysphonia and suffocation. Treatment of choice depends upon the primary complaint of the patient. We present the case of a young female who underwent tracheostomy to relieve respiratory tract obstruction during puberty and was later diagnosed as a case of ectopic lingual thyroid by radioactive iodine uptake and CT scan imaging. She had an associated hypothyroidism; patient was then put on thyroxine and after making her euthyroid she was operated by transoral route and her ectopic lingual thyroid was removed. She was discharged on a maintenance dose of thyroxin.

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.

WAGR syndrome and congenital hypothyroidism in a child with a Mosaic 11p13 deletion.

Wilm's tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome, a rare genetic disorder, is caused by the loss of 11p13 region including PAX6 and WT1. We report novel findings in a 28-month-old boy with aniridia, Wilm's tumor, congenital hypothyroidism, and sublingual thyroid ectopia. He was found to have a mosaic 5.28 Mb interstitial deletion of chromosome 11p13 deleting PAX6 and WT1. In order to clarify the mechanism underlying his thyroid dysgenesis, sequence analysis of candidate thyroid developmental genes was performed. We identified a FOXE1: c.532_537delGCCGCC p.(Ala178_Ala179del) variant that predisposes to thyroid ectopia. Taken together, this is the first report of mosaic 11p13 deletion in association with thyroid dysgenesis. We also propose a model of complex interactions of different genetic variants for this particular phenotype in the present patient.

Thyroid dysfunction and developmental anomalies in first degree relatives of children with thyroid dysgenesis.

BACKGROUND: Familial clustering in patients with permanent congenital hypothyroidism (CH) caused by thyroid dysgenesis (TD) has been reported in developed countries. There is no information on familial TD from developing countries. METHODS: A total of 312 first degree relatives belonging to 80 families of children with TD (group 1) and 40 families of age-matched normal children (group 2) were screened by thyroid ultrasonography, serum total thyroxine (T4) and thyroid stimulating hormone (TSH). RESULTS: Thyroid scintigraphy revealed agenesis in 78.7% of the patients, ectopic gland in 15%, and hypoplasia in 6.2%. The mean thyroid volumes were similar in parents and siblings of both groups. Eight (10.6%) mothers in group 1 were identified to have thyroid hypoplasia as compared with none in group 2 (P=0.03). Serum TSH was significantly higher in group 1 than in group 2 (P=0.004). Sixteen (7.8%) subjects (6 mothers, 5 fathers, and 5 siblings) in group 1 were found to have subclinical hypothyroidism as compared to none in group 2 (P<0.05). Four families were identified to have thyroid developmental anomalies and abnormal thyroid functions accounting for 5% of cases of familial TD in our cohort. CONCLUSION: Thyroid developmental anomalies and thyroid function abnormalities are more frequent in first degree relatives of children with TD as compared with a control population. These findings suggest that possibly there is a genetic component of TD in Indian patients.

Early weaning PCB 95 exposure alters the neonatal endocrine system: thyroid adipokine dysfunction.

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that can severely disrupt the endocrine system. In the present study, early-weaned male rats were administered a single dose of 2,3,6-2',5'-pentachlorinated biphenyl (PCB 95; 32 mg/kg per day, by i.p. injection) for two consecutive days (postnatal days (PNDs) 15 and 16) and killed 24 and 48 h after the administration of the last dose. Compared with the control group, administration of PCB 95 induced a reduction (P<0.01) in serum concentrations of thyroxine, triiodothyronine, and GH and an increase (P<0.01) in the serum concentration of TSH at PNDs 17 and 18. These conspicuous perturbations led to some histopathological deterioration in the thyroid gland characterized by follicular degeneration, edema, fibrosis, hemorrhage, luminal obliteration, and hypertrophy with reduced colloidal contents at PND 18. The dyshormonogenesis and thyroid dysgenesis may be attributed to the elevation of DNA fragmentation at PNDs 17 and 18. Furthermore, this hypothyroid state revealed higher (P<0.01) serum concentrations of leptin, adiponectin, and tumor necrosis factor and lower (P<0.01) serum concentrations of IGF1 and insulin at both PNDs compared with the control group. Interestingly, the body weight of the neonates in the PCB 95 group exhibited severe decreases throughout the experimental period in relation to that of the control group. These results imply that PCB 95 may act as a disruptor of the developmental hypothalamic-pituitary-thyroid axis. Hypothyroidism caused by PCB 95 may impair the adipokine axis, fat metabolism, and in general postnatal development. Thus, further studies need to be carried out to understand this concept.

Thyroid hemiagenesis, ectopic submandibular thyroid tissue, and apparent persistent subclinical thyrotoxicosis.

BACKGROUND: Ectopic thyroid tissue (ETT) is a rare embryological abnormality characterized by the occurrence of thyroid tissue in a site other than its usual location. Thyroid hemiagenesis (HA) is also a very rare abnormality in which one thyroid lobe does not develop properly during embryology. We report a patient with left HA, submandibular ETT, and persistent mildly suppressed serum thyrotropin (TSH). PATIENT: A 38-year-old female patient was admitted with complaints of sweating and palpitations. She had no symptoms of neck compression. Thyroid ultrasonography revealed heterogeneity and hypoechogenicity of the right lobe and absence of the left lobe, the latter being confirmed by computed tomography. There was no ETT in the neck. A thyroid Tc-99m pertechnetate scan demonstrated two distinct areas of radiotracer uptake, one in the right lobe of the thyroid gland and one in the right submandibular region and lobe, but no uptake in the left thyroid bed. The serum free triiodothyronine was 2.89 pg/mL (2.5-3.9 pg/mL), and the serum free thyroxine was 0.86 ng/dL (0.61-1.12 ng/mL). The serum TSH was 0.11 mIU/L (0.34-5.60 mIU/L). CONCLUSIONS: This may be the first reported patient with HA and submandibular ETT. The patient probably also had thyroiditis with mild intermittent thyrotoxicosis based on her suppressed TSH and ultrasonography imaging of the right thyroid lobe.

Thyroid hypoplasia as a cause of congenital hypothyroidism in monozygotic twins concordant for Rubinstein-Taybi syndrome.

Rubinstein-Taybi syndrome (RSTS), a genetic disorder characterized by growth retardation, mental deficiency, dysmorphic face, broad thumbs and large toes, generally affects monozygotic twins concordantly. Thyroid hypoplasia (TH) is a common cause of congenital hypothyroidism (CH) and often accompanies dysmorphic syndromes. A pair of female twins were admitted to our neonatology unit 16 hours after delivery. They were born at 35 weeks of gestation. Both twins had an unusual dysmorphic facial appearance with microcephaly, as well as broad short thumbs and large toes. Based on the presence of characteristic dysmorphic features, the twins were diagnosed as RSTS. Thyroid function tests in the first twin revealed the following results: free thyroxine (T4) 8.4 pg/mL, thyrotropin (TSH) 4.62 mIU/L, thyroglobulin (TG) 213.24 ng/mL and a normal level of urinary iodine excretion (UIE). Thyroid function test results in the second twin in the second week were: free T4 5.9 pg/mL, TSH 9.02 mIU/L, TG 204.87 ng/mL, and normal UIE levels. Thyroid volumes were 0.36 mL and 0.31 mL in the first and second twin, respectively. TH was confirmed by technetium 99 m pertechnetate thyroid scans in both infants. Thyroid function tests normalized with L-thyroxine replacement therapy (10 µg/kg/day) around the end of the 3(rd) week of life. The infants were discharged planning their follow-up by both endocrinology and cardiology units. The rarity of cases of twins with RSTS (concordant) co-existing with CH led us to present this report.

Morphogenesis of the thyroid gland.

Congenital hypothyroidism is mainly due to structural defects of the thyroid gland, collectively known as thyroid dysgenesis. The two most prevalent forms of this condition are abnormal localization of differentiated thyroid tissue (thyroid ectopia) and total absence of the gland (athyreosis). The clinical picture of thyroid dysgenesis suggests that impaired specification, proliferation and survival of thyroid precursor cells and loss of concerted movement of these cells in a distinct spatiotemporal pattern are major causes of malformation. In normal development the thyroid primordium is first distinguished as a thickening of the anterior foregut endoderm at the base of the prospective tongue. Subsequently, this group of progenitors detaches from the endoderm, moves caudally and ultimately differentiates into hormone-producing units, the thyroid follicles, at a distant location from the site of specification. In higher vertebrates later stages of thyroid morphogenesis are characterized by shape remodeling into a bilobed organ and the integration of a second type of progenitors derived from the caudal-most pharyngeal pouches that will differentiate into C-cells. The present knowledge of thyroid developmental dynamics has emerged from embryonic studies mainly in chicken, mouse and more recently also in zebrafish. This review will highlight the key morphogenetic steps of thyroid organogenesis and pinpoint which crucial regulatory mechanisms are yet to be uncovered. Considering the co-incidence of thyroid dysgenesis and congenital heart malformations the possible interactions between thyroid and cardiovascular development will also be discussed.

In the Italian population sexual dimorphism affects pre-natal thyroid migration but not biochemical severity of gland ectopia and pre-natal bone maturation.

UNLABELLED: The aim of the present study was to retrospectively re-evaluate a population of selected infants with congenital hypothyroidism (CH), in order to investigate whether sexual dimorphism affects: a) CH etiology; b) its biochemical severity at the time of screening and recall; c) patients' biochemical response to replacement treatment during the 1st yr of life; d) their bone maturation (BM) at birth; e) their psychomotor status at 1 yr. This retrospective study covers 192 infants (116 females) with persistent CH who were selected from a larger population of CH patients identified during a 10-yr period (1990-1999) by the screening programs of 5 northern, central, and southern regions of Italy. Thirty boys (39.5%) and 66 girls (56.9%) were found to have ectopia, whereas the remaining 46 boys and 50 girls exhibited the other causes of CH. When compared with the prevalence of the remaining causes that of ectopia was significantly higher in girls than in boys (66/116 vs 30/76; chi2=5.57, p<0.025), and sex ratio in ectopia was significantly different also compared with the orthotopic gland group only (66/84 vs 30/51; chi2=6.02, p<0.025). No differences between males and females were detected in the groups with either athyreosis or orthotopic gland. In no groups were there differences between sexes for gestational age, birth auxological data, percentage of newborns with bone retardation or developmental quotient at 1 yr. Thyroid tests at birth, age at TSH normalization and average thyroid tests under L-T4 treatment during the 1st yr did not differ between sexes in any of the groups. CONCLUSIONS: a) in the Italian population sexual dimorphism affects pre-natal thyroid migration but neither biochemical severity of ectopia, nor pre-natal bone maturation and psychomotor development; b) girls with CH do not require higher doses of initial therapy in order to achieve TSH normalization; c) future developmental and molecular studies on ectopia etiology in CH need to take into account the effect of sexual dimorphism.

Analysis of physical and mental development of children with aplasia, hypoplasia and ectopy of the thyroid gland.

OBJECTIVE: Evaluation of clinical and biochemical differences between various forms of thyroid dysgenesia in children. METHODS: The study involved 102 children at the age between 4.8 and 14.2 years who were born with congenital hypothyroidism (CH), as diagnosed by neonatal screening examinations. In all the children diagnosis was settled and the levothyroxine (L-T4) administration was started by the 19th day of life. Out of the examined children, 79 were selected with following three forms of developmental thyroid disorders: Group I--athyroidism (thyroid aplasia or agenesis), Group II--thyroid hypoplasia, Group III--thyroid ectopy. On the basis of neonatal TSH (nTSH) levels obtained by screening and serum TSH, FT4 and Tg concentrations, the severity of hypothyroidism was determined at the time of diagnosis. Physical and mental development of the children was evaluated on the basis of growth and bone age indices and Wechsler's scale, respectively. RESULTS: Developmental disorders were diagnosed in 79 cases (77.4% CH) which included 45 cases (44.1%) of athyroidism, 31 cases (30.4%) of thyroid hypoplasia and 3 cases (2.9%) of thyroid ectopy. The physical and mental development in the studied groups was evaluated as normal. CONCLUSIONS: In the group of children with athyroidism, significantly lower growth indices and IQ values were found in comparison with respective values observed in the other study groups. However, the indices of physical and mental development in all the studied groups were within the normal values for children population. An early diagnosis and early administration of hormonal replacement therapy by L-T4 ensure normal development of children with CH, regardless of underlying causes and associated with them severity of congenital hypothyroidism.