Thyrotropinomas

Author(s):  
Paolo Beck-Peccoz ◽  
Luca Persani

Thyrotropinomas are rare tumours, accounting for no more than 1% of all secreting or nonsecreting pituitary adenomas (1, 2). Since the prevalence of pituitary tumours in the general population is about 0.03%, 1–3 thyrotropinomas are expected to be seen per million people. The number of reported thyrotropinomas increased exponentially in the past years, as a consequence of the introduction of ultrasensitive immunometric assays for thyroid-stimulating hormone (TSH) as first-line test for evaluating thyroid function (1). Based on the finding of measurable serum TSH levels in the presence of elevated thyroid hormone concentrations, many patients previously thought to be affected with Graves’ disease or toxic nodular goitre could be correctly diagnosed as patients with central hyperthyroidism. In our opinion, this latter term is preferable to ‘inappropriate secretion of TSH’, as it more precisely reflects the pathophysiological events underlying such an unusual disorder, where the thyroid hormone negative feedback mechanism is clearly disrupted and TSH itself is responsible for the hyperstimulation of the thyroid gland and the consequent hypersecretion of thyroid hormones (Fig. 2.3.13.1). Central hyperthyroidism is mainly due to autonomous TSH hypersecretion from a thyrotropinoma. However, signs and symptoms of hyperthyroidism along with biochemical findings similar to those found in thyrotropinoma, may be recorded in the minority of patients with resistance to thyroid hormones (RTH) (3, 4). This form of RTH is called pituitary RTH (PRTH), as the resistance to thyroid hormone action appears more severe at the pituitary than at the peripheral tissue level (see Fig. 2.3.13.1). The clinical importance of these rare entities is based on the diagnostic and therapeutic challenges they present. Failure to recognize these different disorders may result in undesirable consequences, such as improper thyroid ablation in patients with central hyperthyroidism or unnecessary pituitary surgery in patients with RTH. Conversely, early diagnosis and correct treatment of thyrotropinomas may prevent the occurrence of complications (visual defects by compression of the optic chiasm, hypopituitarism, etc.) and should improve the rate of cure.

2018 ◽  
Vol 14 (1) ◽  
pp. 39-46
Author(s):  
Lyudmila A. Ruyatkina ◽  
Aguniya A. Molchanova ◽  
Alina S. Ruyatkina ◽  
Lyudmila Y. Rozhinskaya

Thyroid hormone resistance syndrome (RTH) is a rare disorder characterized by reduced peripheral tissue responses to thyroid hormones (TH) and elevated levels of circulating free thyroid hormones. Resistance to thyroid hormone is caused by mutations of the thyroid hormone receptor beta (THRB) gene. In this article, we present case of 26-years-old women who presented with unclear signs and symptoms. Thyroid morphology and function were evaluated with standard ultrasound of the thyroid, scintigraphy and cytological specimen obtained by FNAB. The features of the basic assessment of thyroid status with an emphasis on the concept of “±feedback” of thyroid-stimulating hormone (TSH) and TH. A differential diagnosis of TSH-secreting pituitary adenoma and RTH was discussed. Heterozygous mutation p.P453T in the THRB gene was detected. Thus, the given clinical case demonstrates the necessity of the thorough examination of patients in identifying disorders of the principle of “±feedback”. The observation in dynamics is recommended.


2021 ◽  
Vol 53 (04) ◽  
pp. 272-279
Author(s):  
Chaochao Ma ◽  
Xiaoqi Li ◽  
Lixin Liu ◽  
Xinqi Cheng ◽  
Fang Xue ◽  
...  

AbstractThyroid hormone reference intervals are crucial for diagnosing and monitoring thyroid dysfunction during early pregnancy, and the dynamic change trend of thyroid hormones during pregnancy can assist clinicians to assess the thyroid function of pregnant women. This study aims to establish early pregnancy related thyroid hormones models and reference intervals for pregnant women. We established two derived databases: derived database* and derived database#. Reference individuals in database* were used to establish gestational age-specific reference intervals for thyroid hormones and early pregnancy related thyroid hormones models for pregnant women. Individuals in database# were apparently healthy non-pregnant women. The thyroid hormones levels of individuals in database# were compared with that of individuals in database* using nonparametric methods and the comparative confidence interval method. The differences in thyroid stimulating hormone and free thyroxine between early pregnant and non-pregnant women were statistically significant (p<0.0001). The reference intervals of thyroid stimulating hormone, free thyroxine and free triiodothyronine for early pregnant women were 0.052–3.393 μIU/ml, 1.01–1.54 ng/dl, and 2.51–3.66 pg/ml, respectively. Results concerning thyroid stimulating hormone and free thyroxine reference intervals of early pregnancy are comparable with those from other studies using the same detection platform. Early pregnancy related thyroid hormones models showed various change patterns with gestational age for thyroid hormones. Early pregnancy related thyroid hormones models and reference intervals for pregnant women were established, so as to provide accurate and reliable reference basis for the diagnosing and monitoring of maternal thyroid disfunction in early pregnancy.


Iodine (I2) is essential in the synthesis of thyroid hormones T4 and T3 and functioning of the thyroid gland. Both T3 and T4 are metabolically active, but T3 is four times more potent than T4. Our body contains 20-30 mg of I2, which is mainly stored in the thyroid gland. Iodine is naturally present in some foods, added to others, and available as a dietary supplement. Serum thyroid stimulating hormone (TSH) level is a sensitive marker of thyroid function. Serum TSH is increased in hypothyroidism as in Hashimoto's thyroiditis. In addition to regulation of thyroid function, TSH promotes thyroid growth. If thyroid hormone synthesis is chronically impaired, TSH stimulation eventually may lead to the development of a goiter. This chapter explores the iodide metabolism and effects of Hashimoto's disease.


2016 ◽  
Vol 174 (4) ◽  
pp. 425-432 ◽  
Author(s):  
Chantal Zevenbergen ◽  
Tim I M Korevaar ◽  
Andrea Schuette ◽  
Robin P Peeters ◽  
Marco Medici ◽  
...  

BackgroundLevels of thyroid hormone (TH) and trace elements (copper (Cu) and selenium (Se)) are important for development and function of the brain. Anti-epileptic drugs (AEDs) can influence serum TH and trace element levels. As the relationship between AEDs, THs, and trace elements has not yet been studied directly, we explored these interactions.MethodIn total 898 participants, from the Thyroid Origin of Psychomotor Retardation study designed to investigate thyroid parameters in subjects with intellectual disability (ID), had data available on serum Se, Cu, thyroid stimulating hormone (TSH), free thyroxine (FT4), tri-iodothyronine (T3), reverse T3, T4, and thyroxine-binding globulin (TBG); 401 subjects were on AED treatment. Differences in trace elements according to medication usage was investigated using ANOVA, and associations between trace elements and thyroid parameters were analysed using (non-) linear regression models.ResultsStudy participants were not deficient in any of the trace elements analyzed. AED (carbamazepine, valproate and phenytoin) usage was negatively associated with serum Se and showed compound-specific associations with Cu levels. After correction for drug usage, Se was positively associated with TSH levels, negatively associated with FT4levels, and positively with T3levels. Cu was positively associated with T4, T3, and rT3, which was largely dependent on TBG levels.ConclusionThe subjects with ID did not display profound deficiencies in trace element levels. AEDs were associated with serum Se and Cu levels, while serum Se and Cu were also associated with thyroid parameters. Further studies on the underlying mechanisms and potential clinical importance are warranted.


2005 ◽  
Vol 184 (2) ◽  
pp. 407-416 ◽  
Author(s):  
Michael Muchow ◽  
Ioannis Bossis ◽  
Tom E Porter

Increased thyroid hormone production is essential for hatching of the chick and for the increased metabolism necessary for posthatch endothermic life. However, little is known about the ontogeny and distribution of pituitary thyrotrophs during this period or whether pituitary thyroid-stimulating hormone (TSH) production is regulated by endogenous thyroid hormones during chick embryonic development. This study assessed the abundance and location of pituitary thyrotrophs and the regulation of TSHβ peptide and mRNA levels by endogenous thyroid hormones prior to hatching. TSHβ-containing cells were first detected on embryonic day (e) 11, and the thyrotroph population increased to maximum levels on e17 and e19 and then decreased prior to hatching (d1). Thyrotroph distribution within the cephalic lobe of the anterior pituitary was determined on e19 by whole-mount immunocytochemistry for TSHβ peptide and by whole-mount in situ hybridization for TSHβ mRNA. Thyrotroph distribution within the cephalic lobe was heterogeneous among embryos, but most commonly extended from the ventral medial region to the dorsal lateral regions, along the boundary of the cephalic and caudal lobes. Inhibition of endogenous thyroid hormone production with methi-mazole (MMI) decreased plasma thyroxine (T4) levels and increased pituitary TSHβ mRNA levels on e19 and d1. However, control pituitaries contained significantly more TSHβ peptide than MMI-treated pituitaries on e17 and e19, suggesting higher TSH secretion into the blood in MMI-treated groups. We conclude that thyrotroph abundance and TSH production increase prior to hatching, that thyrotrophs are localized heterogenenously within the cephalic lobe of the anterior pituitary at that time, and that TSH gene expression and secretion are under negative feedback regulation from thyroid hormones during this critical period of development.


Author(s):  
Bo Hyun Park ◽  
Sun Jung Baik ◽  
Hye Ah Lee ◽  
Young Sun Hong ◽  
Hae Soon Kim ◽  
...  

AbstractHypertension is the leading cause of cardiovascular disease worldwide, and both high and low blood pressures are associated with various chronic diseases. Thyroid hormones have profound effects on cardiovascular function, including on blood pressure. Recent studies have shown that childhood hypertension can lead to adult hypertension. Therefore, adequate blood pressure control is important from early life. Employing a life-course approach, we aimed to investigate the association between thyroid hormones and blood pressure in children.A total of 290 children from the Ewha Woman’s University Hospital birth cohort participated in a preadolescent check-up program. We assessed the levels of serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4) and the blood pressure status in these children. Thyroid hormone concentrations were measured using an electro-chemiluminescence immunoassay (ECLIA), and hypertension was defined according to the guideline of the Korea Centers for Disease Control and Prevention.The sex-, age-, and height-adjusted prevalence of hypertension was 27.0% in the present study. On regression analysis, serum FT4 showed significantly negative association with diastolic blood pressure (DBP; β=–8.24, 95% CI: –14.19–2.28, p=0.007). However, these relationships were not significant after adjustment for sex, age, and current body mass index. The levels of serum TSH showed no relationship with mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) after adjustment. No significant differences in serum TSH and FT4 levels according to hypertension status were found.These findings suggest that thyroid hormone is not independently associated with increased blood pressure in euthyroid preadolescents.


2009 ◽  
Vol 55 (7) ◽  
pp. 1380-1388 ◽  
Author(s):  
Jacqueline Jonklaas ◽  
Natasa Kahric-Janicic ◽  
Offie P Soldin ◽  
Steven J Soldin

Abstract Background: Accurate measurement of free thyroid hormones is important for managing thyroid disorders. Ultrafiltration liquid chromatography tandem mass spectrometry (LC-MS/MS) can reliably measure the concentrations of small molecules, including thyroid hormones. Our study was designed to compare free thyroid hormone measurements performed with immunoassay and LC-MS/MS. Methods: We studied the performance of LC-MS/MS in 4 different populations comprising pediatric patients, euthyroid adults, and healthy nonpregnant and pregnant women. The samples obtained from each population numbered 38, 200, 28, and 128, respectively. Free thyroxine, free triiodothyronine, and thyroid-stimulating hormone (TSH) concentrations were documented. Results: LC-MS/MS measurement of free thyroid hormones provided better correlation with log-transformed serum TSH in each population and also the populations combined. The correlations between free thyroxine measured by LC-MS/MS and log TSH in the pediatric outpatients and healthy adults were −0.90 and −0.77, respectively. The correlations for immunoassay were −0.82 and −0.48. The correlations between free triiodothyronine measured by LC-MS/MS and TSH for both pediatric and healthy adult populations were −0.72 and −0.68, respectively. Conclusions: Free thyroid hormone concentrations measured by LC-MS/MS correlate to a greater degree with log TSH values compared to concentrations measured by immunoassay. This correlation was maintained across the patient populations we studied and may reflect the accuracy and specificity of LC-MS/MS. The superior ability of LC-MS/MS to enable documentation of the well-known thyroid hormone–TSH relationship supports the use of this measurement technique in a variety of clinical situations.


2021 ◽  
pp. 75-77
Author(s):  
Meiyappan Kavitha ◽  
Mallaiyan Manonmani

Objectives: Nephrotic syndrome is a common renal disorder seen in children, with proteinuria as the hallmark. Growth retardation is a known feature of nephrotic syndrome, either due to the disease or treatment with steroids. Thyroid hormone strongly inuences growth of the body. So, the present study was undertaken with the objective to assess the thyroid prole in children with nephrotic syndrome Methods: The study involved 41 cases of nephrotic syndrome and 41 age and sex matched controls. Serum total triiodothyronine (T3), total thyroxine (T4), free triiodothyronine (T3), free thyroxine (T4) and thyroid stimulating hormone (TSH) were assessed in these subjects. The thyroid hormones were correlated with urinary protein creatinine ratio. The cases were followed up after one month and the levels of thyroid hormones were reassessed. Results: Total T3, total T4, free T3 and free T4 are signicantly decreased and TSH signicantly increased among cases when compared to controls. TSH is positively correlating with urinary protein creatinine ratio in cases. After one month of treatment, total T3 and total T4 are signicantly increased in cases. Conclusions: The thyroid hormone levels are altered in children with nephrotic syndrome during the episode. A state of subclinical hypothyroidism exists during the nephrotic stage. The alteration is normalized with remission and does not require treatment.


Author(s):  
T. DEVELTERE ◽  
F. DUYCK ◽  
D. VANHAUWAERT ◽  
F. DEDEURWAERDERE ◽  
K. SPINCEMAILLE

TSH-secreting pituitary adenoma: a rare cause of hyperthyroidism Central hyperthyroidism is noted in a 35-year-old man with recurrent panic attacks. Thyroid-stimulating hormone-secreting pituitary adenoma (TSH-secreting adenoma) is found to be the underlying etiology. A pituitary adenomectomy is carried out, with regression of the symptoms and hyperthyroidism. TSH-secreting adenomas are rare and cause hyperthyroidism due to autonomous TSH secretion. In addition to hyperthyroidism, dysfunction of other pituitary axes and neurological problems due to local compression may also be present. Biochemically, TSH adenoma is characterized by elevated levels of thyroid hormones without suppression of the TSH concentration. After analytical interference has been ruled out, additional biochemical and radiological investigations are necessary in the differential diagnosis and to establish diagnostic certainty. Neurosurgical resection is the cornerstone of the treatment, although radiotherapy and somatostatin analogs may also be considered.


Author(s):  
Julian H Barth ◽  
Ahai Luvai ◽  
Nuthar Jassam ◽  
Wycliffe Mbagaya ◽  
Eric S Kilpatrick ◽  
...  

Introduction Reference intervals are dependent on the reference population, the analytical methods and the way the data are handled statistically. Individual method-related differences have been studied but the comparative differences in reference intervals have not. Methods We studied a reference population of healthy adult subjects and measured free thyroxine and thyroid-stimulating hormone by the four most commonly used analytical platforms used in the UK. Subjects were excluded if they were > 65 years or had positive thyroid peroxidase antibodies. We also performed a systematic literature review of thyroid hormone reference interval studies in non-pregnant adults. Results In total, 303 subjects were recruited and 42 excluded. The central 95th centile values for thyroid-stimulating hormone (mIU/L) were Abbott Architect (0.51–3.67); Beckman Unicel DxI (0.57–3.60); Roche Cobas (0.60–4.31) and Siemens Advia Centaur XP (0.63–4.29). The 95th centile values for thyroxine (pmol/L) were Abbott Architect (10.6–15.5); Beckman Unicel DxI (7.9–13.0); Roche Cobas (12.5–19.6) and Siemens Advia Centaur XP (11.8–19.0). We identified 55 papers describing thyroid reference intervals in male and non-pregnant female adults. The values for upper and lower reference intervals by manufacturer varied but were not significantly different for thyroid-stimulating hormone but were for thyroxine. Discussion Our study demonstrates clearly that there are marked variations in the reference intervals for thyroid hormones between analytical platforms. There is an urgent need for standardization of thyroid hormone assays to permit transferability of results. Until then, guidelines will need to reflect this method-related difference.


Sign in / Sign up

Export Citation Format

Share Document