Toxic adenoma in childhood — case report

ABSTRACT. A 12-year-old girl was noted to have a left sided thyroid nodule on routine examination. Although clinically euthyrold she was found to have an elevated T3 value, and the TSH failed to rise following TRH injection. Thyroid scan showed a hyperfunctioning nodule in the left lobe of the thyroid gland. Following surgical removal of the nodule the patient became biochemically euthyroid and a repeat thyroid scan demonstrated the previously suppressed normal right lobe.     

Autonomous thyroid nodules in adolescents: clinical characteristics and results of TRH testing

Seven adolescents with autonomous thyroid nodules were evaluated over a three-year period. They had hyperfunctioning nodules on radionuclide scan which failed to suppress with exogenous administration of thyroid hormone. They were clinically euthyroid and had normal T4, free T4, and basal TSH values. However, as a group they had elevated total serum T3 concentrations, blunted TSH response to TRH, and accelerated closure of cranial sutures, all of which suggested subtle hyperthyroidism. These patients have been followed for one to five years. Four have undergone partial thyroidectomy because of persistent elevation in the serum T3 concentration or enlargement of the nodule. The clinical presentation and laboratory findings in this group are similar to those found in adults with autonomous nodules.     

Hyperfunctioning Thyroid Nodules in Children and Adolescents

ABSTRACT. Eight children and adolescents, seven female and one male, aged 7.1 to 15.0 years, referred over a 12-year period for a solitary mass in an otherwise normal thyroid gland, exhibited a hyperfunctioning nodule on thyroid scintiscan. Tracer uptake in the surrounding thyroid tissue was reduced or completely suppressed, but could be restored after TSH stimulation. Only one patient had mild clinical hyperthyroidism with normal T4 but increased T3 serum levels and blunted TSH responsiveness to TRH. A similar hormonal pattern suggestive of subclinical hyperthyroidism was found in three other subjects who were clinically euthyroid. One patient initially euthyroid progressed to subclinical hyperthyroidism two years later. In the whole group a significant negative relationship was found between serum T3 level and TRH-stimulated TSH peak (r= -0.829, p<0.02). All the patients underwent selective surgery after a 3-month to 2-year period of follow-up. Microscopic examination was consistent with adenoma in seven patients, while in one case a well-encapsulated papillary adenocarcinoma was found. Though hyperfunctioning nodules are seldom malignant, their surgical removal must be recommended when they become thyrotoxic, exceed 3 cm or show progressive enlargement.     

Hyperfunctioning thyroid nodules in children and adolescents

Eight children and adolescents, seven female and one male, aged 7.1 to 15.0 years, referred over a 12-year period for a solitary mass in an otherwise normal thyroid gland, exhibited a hyperfunctioning nodule on thyroid scintiscan. Tracer uptake in the surrounding thyroid tissue was reduced or completely suppressed, but could be restored after TSH stimulation. Only one patient had mild clinical hyperthyroidism with normal T4 but increased T3 serum levels and blunted TSH responsiveness to TRH. A similar hormonal pattern suggestive of subclinical hyperthyroidism was found in three other subjects who were clinically euthyroid. One patient initially euthyroid progressed to subclinical hyperthyroidism two years later. In the whole group a significant negative relationship was found between serum T3 level and TRH-stimulated TSH peak (r = -0.829, p less than 0.02). All the patients underwent selective surgery after a 3-month to 2-year period of follow-up. Microscopic examination was consistent with adenoma in seven patients, while in one case a well-encapsulated papillary adenocarcinoma was found. Though hyperfunctioning nodules are seldom malignant, their surgical removal must be recommended when they become thyrotoxic, exceed 3 cm or show progressive enlargement.     

Peripheral insensitivity to thyroid hormones in a euthyroid girl with goitre.

A 9-year-old girl was euthyroid with a small goitre, exophthalmos, scaphocephalic skull, minor sketelal abnormalities, and raised serum thyroid hormone concentrations. Other members of the family did not have goitres and their thyroid hormone levels were normal. From age 3 years the patient was treated for Graves''s disease, but after 4 years treatment was stopped because of enlargement of the goitre. Despite increased serum thyroxine (T4), free T4 (FT4), and triiodothyronine (T3), basal serum TSH, and the TSH response to thyrotropin-releasing hormone (TRH) were normal. Pituitary refractoriness was present because full suppression of the TSH response to TRH was achieved only after daily administration of 500 micrograms thyroxine. Urinary excretion of hydroxyproline, and the activity of red cell glucose-6-phosphate dehydrogenase remained normal when excess T4 was administered, demonstrating the tissue resistance to thyroid hormones. Peripheral lymphocytes were found to have nuclear receptors for T3 with normal affinity, but the relatively low binding capacity indicated that the biochemical defect might be a deficiency of nuclear receptor protein. The findings in this patient differ somewhat from previously reported cases of peripheral resistance to thyroid hormones.     

McCune-Albright syndrome in a male child: a clinical and endocrinologic enigma.

A 6 5/12-year-old boy with polyostotic fibrous dysplasia, café-au-lait pigmentation of the skin, and precocious pubertal development was studied for two years. Parathormone, calcium, phosphorus, testosterone, cortisol, and growth hormone levels were within normal limits. Urinary 17-ketosteroids, 17-ketogenic steroids, and estrogens were at the upper limits of normal. After GnRH stimulation, there was only a very slight increase in LH and no increase in FSH. There was no increase in TSH after TRH, and plasma levels of T4 and T3 were normal. The plasma prolactin level was within normal limits, and increased after TRH stimulation (with a second, delayed upsurge). Abnormal distribution of 131I in the thyroid was evident, without clearcut evidence of hyperfunctioning areas after TSH stimulation and T3 suppression tests followed by conventional scanning and gamma camera scintiphotography. Our findings do not support the claimed, single, hypothalamic origin of the disease that is presumed to result in overproduction of releasing hormones; they are more in keeping with a pleiotropic, scattered peripheral lesion, possibly of embryonal origin.     

Evidence of hypothalamic-pituitary thyroid abnormalities in children with end-stage renal disease

Patients with end-stage renal disease may have abnormalities of growth and of gonadal and thyroid hormones, so we attempted to determine the mechanisms that may be involved in the altered thyroid function. We evaluated serum thyroid hormone levels, their changes immediately after hemodialysis, the serum thyrotropin (thyroid-stimulating hormone (TSH) response to thyrotropin releasing hormone, and the circadian pattern of serum TSH in nine children with end-stage renal disease who were between 7 1/2 years and 17 years 1 month of age. Seven patients had been receiving hemodialysis for a median of 3.3 years; the other two were receiving continuous ambulatory peritoneal dialysis. Four patients had low serum total thyroxine (T4) values, and all nine had low free T4 values. Mean concentrations of total T4, free T4, and total triiodothyronine (T3), which were significantly less than normal before hemodialysis, returned to normal levels immediately after dialysis. Postdialysis thyroid hormone increases did not correlate with the decrease in weight or the increase in hematocrit observed immediately after dialysis. All but one patient had basal TSH levels within the normal range. Three patients had a deficient TSH response to thyrotropin releasing hormone, and the TSH response was prolonged in all of them. The mean (+/- SD) nocturnal TSH surge was 50 +/- 68%. Five of the eight patients studied had a nocturnal TSH surge below the normal range (95% confidence limits 47% to 300%). Serum free T4 values correlated with the TSH nocturnal surge (r, 0.73; p less than 0.05). Our findings support the hypothesis that some patients with end-stage renal disease have central hypothyroidism.     

Pseudohypoparathyroidism with hypothyroidism (author's transl)

This is a report about three children suffering from pseudo-hypoparathyroidism type I and moderate primary hypothyroidism. The thyroid dysfunction was characterised by slightly low plasma thyroxine and high basal TSH showing an increased response to TRH. T3 and rT3 were within normal limits, the size of the thyroid glands and also bone age were normal. The plasma concentrations of T4 and TSH and the response of TSH to TRH were no different during hypocalcemia from those obtained in normocalcemia during vitamin D treatment. Thyroxine treatment could normalize T4 and TSH. Moderate hypothyroidism is frequently present in pseudohypoparathyroidism. It has to be assumed that the same genetical defect of the second messenger, already proved to exist in the kidneys of patients with pseudohypoparathyroidism may also exist in the thyroid gland.     

Thyroid dysfunction in antiretroviral treated children

BACKGROUND: A high rate of thyroid disorders has been described in HIV-infected adults treated with highly active antiretroviral therapy (HAART), but data on children are lacking. We aimed to assess thyroid function in pediatric patients. METHODS: Fifty-two HIV-infected children receiving HAART were assessed for signs of thyroid dysfunction and serum concentrations of thyrotropin (TSH), free thyroxin (FT4), free triiodothyronine (FT3), thyroglobulin (TG), reverse triiodothyronine (rT3), anti-TG and antimicrosomal (anti-TSM) antibodies. RESULTS: Eighteen (35%) children showed thyroid abnormalities: isolated low FT4 value in 16; subclinical hypothyroidism in 1; and symptomatic hypothyroidism in 1.Children with low FT4 values as compared with the 34 children without thyroid dysfunction were similar for stage of disease, number of patients with undetectable HIV-RNA, FT3, TSH, TG, rT3, anti-TSM and anti-TG values, whereas they had shorter duration of HAART exposure (P = 0.019) and lower CD4 cell percentage (P = 0.035). The thyrotropin-releasing hormone (TRH) test was normal in all children with low FT4 values. Among children with low FT4, FT4 concentrations correlated positively with CD4 cell percentage (P < 0.05) and duration of HAART exposure (P < 0.05).The case with subclinical hypothyroidism had high basal TSH (7.3 microunits/ml), normal TSH response to TRH test and normal FT4, FT3, TG, rT3, anti-TG and anti-TSM antibodies.The case with symptomatic hypothyroidism had low FT4 (6.6 pg/ml) and high TSH (44 microunits/ml), TG (55 ng/ml), anti-TG (666 IU/ml) and anti-TSM (123 IU/ml). CONCLUSION: Thyroid abnormalities occur frequently in HAART-treated children even in the absence of clinical symptoms. These data suggest a need of regular thyroid function monitoring.     

Thyroxine-binding globulin deficiency in early childhood. Postnatal changes in serum concentrations of thyroid hormones and thyroid hormone-binding proteins

Serial determinations of serum thyroxine (T4), triiodothyronine (T3), thyrotropin (TSH), thyroid hormone-binding globulin (TBG), prealbumin (TBPA) and albumin were performed in a euthyroid girl with TBG deficiency and in her mother for a period of 22 months after delivery. At 8 days old the child had a serum TBG concentration around 50% of normal level which remained essentially unchanged during infancy. Total serum T4 and T3 concentrations were low, the free serum T4, free serum T3 and serum TSH concentrations were normal. The mother had received thyroid hormone from the age of 15 years. Her serum TBG level at 6 weeks post partum was similar to that of non-pregnant adults but decreased to about 50% of normal level, indicating a TBG deficiency. She remained euthyroid after withdrawal of T4 therapy. Serum TBPA and albumin concentration were normal in mother and child. An X-linked inheritance of the TBG deficiency was suggested from a study of the family.     

Thyroid function during exchange transfusion.

The changes in plasma thyroid hormone concentration were studied during exchange transfusion performed for haemolytic disease. 24 transfusions were performed using blood preserved with acid-citrate and dextrose and in 11 cases 10 or 50 mug glucagon was added to the donor blood. Plasma tri-iodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroid hormone binding capacity, and free thyroxine index were measured in the donor blood and in the infant at the start and at intervals during the transfusion. Before transfusion the plasma TSH levels of the infants fell as postnatal age indreased and plasma T3 and T4 were correlated with one another. In 20 transfusions the mean infant/donor ratio of TSH was approximately 10, of T4 3, and of T3 2. During these transfusions there was a progressive fall in the infant's plasms TSH, T4, and T3 concentration. In 3 transfusions in which the donor plasma TSH was greater than that of the infant, plasma TSH levels rose during the transfusion and in 2 cases this was associated with a late rise in plasma T3 levels. The addition of glucagon to donor blood had no effect on thyroid hormone levels. It is concluded that erythroblastotic infants have normal thyroid function and that they became biochemically hypothyroid during transfusion. Acute changes in plasma thyroid hormone and glucagon concentration do not induce TSH responses by the neonatal pituitary during the period of the exchange transfusion.     

Thyroid hormone unresponsiveness in two siblings with intrauterine growth retardation and exophthalmos

Two cases of a brother and a sister with thyroid hormone unresponsiveness are described. They had large goiters and high levels of thyroid hormones in the face of clinical euthyroidism. The birth weight of the brother was low for his gestational age. He was also lean and exophthalmic, as is often seen in Graves' disease.Abbreviations used TSH thyrotropin - T4 thyroxine - PBI protein-bound iodine - BMR basal metabolic rate - T3 triiodothyronine - TRH thyrotropin releasing hormone - RT3U resin triiodothyronine uptake - TBG-C thyroxine binding capacity of thyroxine binding globulin - LATS long acting thyroid stimulator - hGH human growth hormone - LH luteinizing hormone - FSH follicle stimulating hormone - Gn-RH gonadotropin releasing hormone     

Ectopic thyroid: residual function after withdrawal of treatment in infancy and later childhood

Plasma thyroxine (T4) and thyrotrophin (TSH) were estimated in 34 children identified by neonatal hypothyroid screening and subsequently found to have ectopic thyroid tissue on isotope scan. Before treatment plasma T4 ranged from 8-143 nmol/l and TSH from 39-1,230 mU/l. After one week off treatment during their second year, repeat T4 in 26 of these cases showed a significant correlation with the pre-treatment values (r = 0.57). However, only 3 of the 5 children with pre-treatment T4 levels over 100 nmol/l at diagnosis had normal T4 values when retested. Similarly, when 10 children with pre-treatment T4 values over 65 nmol/l were retested off treatment at the ages of 5.8-8.2 years, only 4 had plasma T4 levels in the normal range. These results illustrate the wide range of thyroid function which can occur in children with ectopic thyroid tissue and indicate that some continue to have near-normal thyroid function for considerable periods. However, pre-treatment T4 results do not allow accurate identification of these latter cases.     

Thyrotropin, prolactin and growth hormone response to synthetic thyrotropin-releasing hormone in newborn infants.

The effects of 50 microgram synthetic thyrotropin-releasing hormone (TRH) intravenously on thyrotropin (TSH), prolactin (PRL) and growth hormone (GH) levels were studied in 8 normal male newborns during the first hours of life. Mean plasma GH concentrations were similar to baseline values during the period of study; on the contrary, plasma PRL and TSH values increased in all infants after TRH administration. These data demonstrate a normal pituitary reserve of PRL and TSH in the early period of human life.     

Ectopic Thyroid: Residual Function after Withdrawal of Treatment in Infancy and Later Childhood

ABSTRACT. Plasma thyroxine (T4) and thyrotrophin (TSH) were estimated in 34 children identified by neonatal hypothyroid screening and subsequently found to have ectopic thyroid tissue on isotope scan. Before treatment plasma T4 ranged from 8–143 nmol/1 and TSH from 39–1230 mU/l. After one week off treatment during their second year, repeat T4 in 26 of these cases showed a significant correlation with the pre-treatment values ( r = 0.57). However, only 3 of the 5 children with pre-treatment T4 levels over 100 nmol/1 at diagnosis had normal T4 values when retested. Similarly, when 10 children with pre-treatment T4 values over 65 nmol/1 were retested off treatment at the ages of 5.8–8.2 years, only 4 had plasma T4 levels in the normal range. These results illustrate the wide range of thyroid function which can occur in children with ectopic thyroid tissue and indicate that some continue to have near-normal thyroid function for considerable periods. However, pre-treatment T4 results do not allow accurate identification of these latter cases.     

Thyrotrophin estimation in diagnosis and treatment of childhood thyroid disorders

Serum thyrotrophin (TSH) was estimated by double-antibody radioimmunoassay in 200 children aged 2 months to 16 years with normal thyroid function. There was no apparent variation in TSH with age or sex and only 4 children had TSH levels greater than 5 muU/ml. High TSH values were obtained in 9 children with primary hypothyroidism, in 3 children with thyroiditis, and in one girl with a lingual thyroid. Moderately raised TSH was found in 3 girls with thyroiditis, 2 brothers with goitres due to enzyme defect, and a girl with an ectopic thyroid. In one girl with a defect of iodine organification and in 3 boys with thyroxine binding globulin deficiency the TSH levels were normal despite very low serum thyroxine values. Serum TSH was also estimated in 20 children during treatment for primary hypothyroidism. 3 of these children showed slightly raised TSH levels despite apparently adequate replacement therapy with L-thyroxine. One girl showed a very high TSH level 3 weeks after treatment had been temporarily withdrawn.     

Thyrotrophin estimation in diagnosis and treatment of childhood thyroid disorders.

Serum thyrotrophin (TSH) was estimated by double-antibody radioimmunoassay in 200 children aged 2 months to 16 years with normal thyroid function. There was no apparent variation in TSH with age or sex and only 4 children had TSH levels greater than 5 muU/ml. High TSH values were obtained in 9 children with primary hypothyroidism, in 3 children with thyroiditis, and in one girl with a lingual thyroid. Moderately raised TSH was found in 3 girls with thyroiditis, 2 brothers with goitres due to enzyme defect, and a girl with an ectopic thyroid. In one girl with a defect of iodine organification and in 3 boys with thyroxine binding globulin deficiency the TSH levels were normal despite very low serum thyroxine values. Serum TSH was also estimated in 20 children during treatment for primary hypothyroidism. 3 of these children showed slightly raised TSH levels despite apparently adequate replacement therapy with L-thyroxine. One girl showed a very high TSH level 3 weeks after treatment had been temporarily withdrawn.     

Thyroid function in thalassaemia major.

Serum concentrations of T4, T3, rT3, and TSH were measured by radioimmunoassay in 45 patients suffering from beta-thalassaemia. A TRH stimulation test was performed and the binding capacity of TBG and TBPA for T3 and T4 measured by reverse flow zone electrophoresis in a group of these patients. Mean T4 serum concentration was lower in thalassaemic patients than controls; T3, rT3, TSH levels, and the pituitary response to TRH were normal. TBPA binding capacity for thyroxine was greatly decreased, probably due to iron overload impairing the liver function. The decreased circulating total thyroxine might be explained by the reduced TBPA capacity, serum free thyroid hormone concentration total thyroxine might be explained by the reduced TBPA capacity, serum free thyroid hormone concentration values being normal. It is concluded that thalassaemic children are euthyroid, despite often having low-normal or subnormal thyroxine levels.     

THYROXINE-BINDING GLOBULIN DEFICIENCY IN EARLY CHILDHOOD

ABSTRACT. Jacobsen, B. B., Hansted, L. C, Brandt, N. J., Haahr, J., Hummer, L., Munkner, T. and Sorensen, S. S. (Department of Paediatrics, Viborg Hospital, Children's Hospital Fuglebakken, Department of Paediatrics, Section of Clinical Genetics and Department of Nuclear Medicine, Rigshospitalet, Copenhagen, Denmark). Thyroxine-binding globulin deficiency in early childhood. Postnatal changes in serum concentrations of thyroid hormones and thyroid hormone-binding proteins. Acta Paediatr Scand, 70:155, 1981. –Serial determinations of serum thyroxine (T4), triiodothyronine (T3), thyrotropin(TSH), thyroid hormone-binding globulin (TBG), prealbumin (TBPA) and albumin were performed in a euthyroid girl with TBG deficiency and in her mother for a period of 22 months after delivery. At 8 days old the child had a serum TBG concentration around 50% of normal level which remained essentially unchanged during infancy. Total serum T4 and T3 concentrations were low, the free serum T4, free serum T3 and serum TSH concentrations were normal. The mother had received thyroid hormone from the age of 15 years. Her serum TBG level at 6 weeks post partum was similar to that of non-pregnant adults but decreased to about 50% of normal level, indicating a TBG deficiency. She remained euthyroid after withdrawal of T4 therapy. Serum TBPA and albumin concentrations were normal in mother and child. An X-linked inheritance of the TBG deficiency was suggested from a study of the family.     

Subclinical hypothyroidism in infancy (author's transl)

Clinical symptoms of hypothyroidism (constipation, macroglossia, umbilical hernia, typical face hyperbilirubinaemia) were found in a 4 months old infant. Body height and activity were normal and the skin did not show the typical dryness. Total-thyroxin (T4) level was normal as well as basal thyrotropin (TSH), only after stimulation with thyrotropin releasing hormone (TRH) an exaggerated response was observed. These hormonal findings are typical for subclinical hypothyroidism, a well known disturbance in adults. The clinical as well as therapeutic considerations are discussed in this patient.