Prevalence of subclinical hyperthyroidism and relationship between thyroid hormonal status and thyroid ultrasonographic parameters in patients with non-toxic nodular goitre

Long-Term Effects of 0.1 mg Recombinant-Human-Thyrotropin-Stimulated Fixed-Dose Radioiodine Therapy in Patients with Recurrent Multinodular Goiter after Surgery

(1) Background: After thyroid malignancy is ruled out, treatment options for multinodular goiter patients include surgery, levothyroxine suppressive therapy, and 131-I therapy. Surgery effectively reduces goiter size but carries risks of surgical and anesthetic complications. 131-I therapy is the only nonsurgical alternative, but its effectiveness diminishes with goiter size and depends on iodine sufficiency. This study aimed to assess the efficacy and safety of 0.1 mg rhTSH as an adjuvant to a fixed dose of 131-I therapy in patients with a recurrence of large multinodular goiter, several years after the initial thyroidectomy. (2) Methods: 14 patients (13 females and 1 male), aged 59.14 ± 15.44 (range, 35-78 years) received 11mciu of 131-I, 24 h after the administration of 0.1 mg rhTSH. The primary endpoint was the change in thyroid volume (by ultrasound measurements) as well as in the diameter of the predominant nodule during a follow-up period of 10 years. Secondary endpoints were the alterations in thyroid function and potential adverse effects. (3) Results: A significant decrease in the volume of initial thyroid remnants (32.16 ± 16.66 mL) was observed from the first reevaluation (at 4 months, 23.12 ± 11.59 mL) as well as at the end of the follow-up period (10 years, 12.62 ± 8.76 mL), p < 0.01. A significant reduction in the dominant nodule was also observed (from 31.71 ± 10.46 mm in the beginning to 26.67 ± 11.05 mm). (4) Conclusions: Further investigation is needed since this approach could be attractive in terms of minimizing the potential risks of reoperation in these patients.

Surgical Management of Substernal Thyroid Goiters

Substernal thyroid goiters can present with progressive symptoms involving compression of vital structures such as the esophagus, trachea, or large vessels. A multidisciplinary approach is critical when diagnosing and treating these patients. This article discusses patient presentation, workup, and management options for patients with substernal goiter as well as surgical pearls to minimize risk of complications.

Management of Retrosternal Goiter in Resource-Limited Settings: Outcomes From 28 Cases Using Cervical Approach

Background Despite thyroidectomy being the preferred approach for retrosternal goiter (RSG), controversies surround its rationale in asymptomatic cases. This study aimed to investigate the treatment of RSG in resource-limited settings. Methods A retrospective study conducted between April 2010 and June 2022 included 28 RSG cases who underwent thyroidectomy using the cervical approach at Al-Nasar Hospital, Ibb, Yemen. A bivariate analysis was performed to investigate the risk factors for postoperative complications. Results The main age was 49.4±9.9 years, and most of them (60.7%) were females. The main symptoms were cervical mass appearance and breathing difficulty in 75 %, and 32.1%, respectively. Twenty-four (86%) cases were classified as Grade 1 (above aortic arch) and four (14%) cases were classified as Grade 2 (aortic arch to the pericardium). All patients underwent total thyroidectomy through the cervical approach without needing sternotomy. The mean operative time was 121.9±26.7min (99-200 min) and the mean intraoperative bleeding was 321.2±137.4 mL. Postoperatively, the malignant entity was histopathologically proven in seven patients (25%). The postoperative complications (14%) were transient hypocalcemia in two (7.1%) and hematoma in two (7.1%). Older age, bigger thyroid mass, extension below the aortic arch (Grade 2), longer operative time and bleeding, intensive care unit admission, and malignant features are associated with postoperative complications (all p < 0.05). Conclusion Cervical approach for patients with RSG in our experience is an optimum, feasible, and less invasive surgical approach, in a resource-limited setting. Older age, bigger thyroid, extension below the aortic arch, longer operative time and bleeding, intensive care unit admission, and malignant features are associated with postoperative complications.

Is TSH necessary for initial assessment of thyroid nodules?

OBJECTIVE

The use of thyrotropin (TSH) in the initial assessment of thyroid nodules is inefficient and leads to unnecessary assessment costs. We compared the total costs of thyroid nodule assessment with or without the use of TSH in the initial assessment.

METHODS

A total of 1808 patients with thyroid nodules received TSH, fine-needle aspiration (FNA) and thyroid scintigraphy (TS) assessment, including 83 autonomously functioning thyroid nodule (AFTN) cases and 1725 non-AFTN cases. The total costs of the TSH strategy and non-TSH strategies were compared. The ratio of single-use costs of FNA to TS (C_FNA/TS ) was used as the main outcome measure.

RESULTS

Only when 6·03 ≤ C_FNA/TS ≤ 27·17, the lowest total costs were associated with using the conventional TSH strategy. When C_FNA/TS <6·03 or C_FNA/TS >27·17, the lowest costs were found with FNA and TS, respectively.

CONCLUSION

From the perspective of cost economics, in iodine-sufficient areas, we recommend that the decision on the use of TSH for the initial assessment of thyroid nodules should be based on the testing costs of FNA and TS in that medical unit.

Which Is the Ideal Treatment for Benign Diffuse and Multinodular Non-Toxic Goiters?

Patients with large benign goiters often present local compressive symptoms that require surgical treatment, including dysphagia, neck tightness, and airway obstruction. In contrast, patients with such goiters who remain asymptomatic may be observed after exclusion of malignancy. The use of levothyroxine (LT4) to reduce the volume of the goiter is still a controversial treatment for large goiters, and the optimal surgical procedure for multinodular goiter is still debatable. Radioiodine is a safe and effective treatment option when used alone or in combination with recombinant human TSH. This review discusses current therapeutic options to treat diffuse and multinodular non-toxic benign goiters.

Approach to the patient with nontoxic multinodular goiter

Thyroid nodules are very common, and although the majority are benign, approximately 5% may harbor malignancy. The evaluation of the patient with solitary thyroid nodule is generally straightforward and will typically include measurement of serum TSH to assess thyroid function and fine-needle aspiration biopsy of the nodule, with or without ultrasound (US) guidance. The approach to the patient with nontoxic multinodular goiter represents a more difficult problem for the clinician. All patients should have serum TSH measured to assess functional thyroid status and US examination to evaluate the number, size, and sonographic features of the nodules and assist in the selection of nodules that may need fine-needle aspiration biopsy. Patients with nodules yielding malignant cytology should be referred for surgery. Given the lack of reliable markers to predict biological behavior of nodules with suspicious (indeterminate) cytology, patients with such nodules are generally advised to have surgery, unless autonomous function of these nodules can be confirmed by scintigraphy. Most of these patients, however, will ultimately prove to have benign follicular tumors. Many patients with benign but large goiters may experience clinical symptoms of pressure, such as dysphagia, choking sensation, or airway obstruction. Such patients will often require surgery for alleviation of symptoms. In the absence of malignancy, asymptomatic patients may be observed. Radioactive iodine, commonly used in many parts of Europe, is safe and effective and may be a reasonable option for many patients. Periodic follow-up with neck palpation and US exam is recommended for all patients.

Analysis of the sodium iodide symporter expression in histological slides from a nodular goiter

BACKGROUND

The aim of the study was analysis at both the level and the cell site of the sodium/iodide symporter (NIS) in histological slides from hot, warm, and cold nodules and extranodular parenchyma according to scintigraphy.

METHODS

The study population consisted of 97 people who underwent surgery for a toxic nodular goiter (26 patients) or a non-toxic nodular goiter (71 patients). Immunohistochemical study was performed with 198 histological slides from hot, warm, and cold nodules (study slides) and the extranodular parenchyma (control slides). The level of NIS expression was estimated objectively using the computerized image analysis system, Quantimet 600S (Leica, Cambridge, UK).

RESULTS

We found significantly higher NIS expression in hot nodules than in cold nodules and in warm nodules than in cold ones. We found significantly higher NIS expression in hot and warm nodules than in the surrounding parenchyma. The level of NIS expression did not differ significantly between cold nodules and the collateral tissues.

CONCLUSIONS

Our data indicate that NIS protein participates in the development of hyperthyroidism in the course of a nodular goiter. We confirm that the functional state of a nodular goiter is determined by NIS expression in nodules, not in collateral parenchyma. The low metabolism of cold nodules does not simply result from decreased level of NIS protein or its defective targeting to the cell membrane. The observation of NIS in the cell cytoplasm of hot nodules seems to indicate that the intracellular localization of NIS does not determine loss of its activity.

Management of simple nodular goiter: current status and future perspectives

The simple nodular goiter, the etiology of which is multifactorial, encompasses the spectrum from the incidental asymptomatic small solitary nodule to the large intrathoracic goiter, causing pressure symptoms as well as cosmetic complaints. Its management is still the cause of considerable controversy. The mainstay in the diagnostic evaluation is related to functional and morphological characterization with serum TSH and (some kind of) imaging. Because malignancy is just as common in patients with a multinodular goiter as patients with a solitary nodule, we support the increasing use of fine-needle aspiration biopsy (cytology). Most patients need no treatment after malignancy is ruled out. In case of cosmetic or pressure symptoms, the choice in multinodular goiter stands between surgery, which is still the first choice, and radioiodine if uptake is adequate. In addition to surgery, the solitary nodule, whether hot or cold, can be treated with percutaneous ethanol injection therapy. If hot, radioiodine is the therapy of choice. Randomized studies are scarce, and the side effects of nonsurgical therapy are coming into focus. Therefore, the use of the optimum option in the individual patient cannot at present be based on evidence. However, we are of the view that levothyroxine, although widely used, should no longer be recommended routinely for this condition. Within a few years, the introduction of recombinant human TSH and laser therapy may profoundly alter the nonsurgical treatment of simple nodular goiter.

Hyperplasia versus adenoma in endocrine tissues: are they different?

The traditional view holds that hyperplasia of endocrine glands is secondary to oversecretion of a trophic hormone. However, in most cases, the mechanism underlying this growth is the spontaneous proliferation of benign neoplasias. Pathologists still depend on subtle morphological criteria to delineate and further classify these tumours. Owing to their variable architecture, a bewildering nomenclature has emerged for these tumours, exemplified by the many names applied to the goitrous thyroid gland: hyperplasia, adenomatous goitre, adenomatoid nodules, benign nodular thyroid disease, adenoma, etc. This article reviews the evidence suggesting that: (1) the varied types of benign neogeneration of endocrine tissue, the spectrum of which ranges from 'simple hyperplasia' to 'true adenoma', involve the same process; (2) even clonality of a growing lesion cannot distinguish hyperplasia from neoplasia; and (3) the basic processes in both cases are not different from those that cause benign tumours in other organs.

Multinodular goitre: 'much more to it than simply iodine deficiency'

For over a century, multinodular goitre (MNG) has been looked upon as the simple consequence of iodine deficiency. This view is now no longer tenable. Indeed, many characteristics of MNG do not fit with the iodine deficiency concept. For example, nodular goitre is a frequent disease even in those countries where the population is never exposed to iodine shortage. Moreover, neither multinodularity, nor the proverbial heterogeneity of growth and function or the autonomous, thyroid stimulating hormone (TSH)-independent growth of many goitres are compatible with the iodine deficiency concept, let alone subclinical or overt thyrotoxicosis which often complicates the course of a MNG. Recent investigations have led to the conclusion that MNGs are true benign neoplasias that are due to the high intrinsic growth potential of a variable, genetically predetermined fraction of all thyrocytes. Gross and heritable metabolic and functional differences between the individual thyrocytes, from which new follicles are generated during goitrogenesis, are the cause of the often spectacular functional and structural heterogeneity of MNG. Superimposed iodine deficiency changes the epidemiology, but not the basic mechanisms of goitrogenesis. These new pathogenetic concepts have a profound impact on the clinical management of MNG.

Syndromes of thyrotoxicosis with low radioactive iodine uptake

It is very important to diagnose correctly the etiology of thyrotoxicosis, because the course and treatment of thyrotoxicosis with low radioactive iodine uptake differ significantly from that of hyperthyroidism due to Graves' disease or toxic nodular goiter. Many causes of subacute thyroiditis have been identified producing a characteristic course of transient hyperthyroidism, followed by hypothyroidism, and usually recovery. Ectopic hyperthyroidism includes factitious thyroid hormone ingestion, struma ovarii, and, rarely, large deposits of functioning thyroid cancer metastases. Iodine-induced hyperthyroidism may be associated with low radioiodine uptakes. Amiodarone-associated hyperthyroidism may be the result of subacute thyroiditis or iodine-induced hyperthyroidism; assessment and treatment can be quite challenging.

Subclinical Graves' disease as a cause of subnormal TSH levels in euthyroid subjects

In order to elucidate causes of subclinical thyrotoxicosis, we reviewed records of thyroid function tests obtained in our hospital between 1990 and 1992 showing normal thyroid hormones and subnormal TSH levels, and analyzed underlying clinical conditions of the patients. Of 186 patients with normal T4 and/or free T4 and normal T3 and/or free T3 but subnormal TSH (< 0.1 mU/l) levels in serum, 150 were under treatment with antithyroid drugs for hyperthyroid Graves' disease or with thyroid hormones for hypothyroidism. Twelve were in remission after treatment for Graves' disease, and 4 had destructive thyroiditis. Of the remaining 20 patients, 4 had autonomously functioning thyroid nodule (AFTN), 9 had euthyroid ophthalmic Graves' disease (EOG), and 7 had diffuse goiter without apparent ophthalmopathy (DG). When thyroid stimulating antibodies (TSAb) were measured in the last 3 groups of the patients, they were detected in none with AFTN but in all patients with EOG and DG. These 7 DG patients without ophthalmopathy had a clinical feature showing unstable thyroid functions, changeable to euthyroidism, overt hyperthyroidism and even hypothyroidism during follow-up. In conclusion, TSAb measurement is useful for detection of subclinical Graves' disease in euthyroid subjects with subnormal TSH levels in serum.

The many causes of subclinical hyperthyroidism

Subclinical hyperthyroidism, defined as serum thyroid hormone levels in the reference range with low serum TSH concentration, is a well recognized clinical entity, but little information is available concerning the prevalence of the disorders that produce it. We conducted a 24-month retrospective survey of subclinical hyperthyroidism patients referred to a university hospital nuclear medicine service for diagnostic studies. Twenty-four consecutive patients were evaluated (22 outpatients and 2 inpatients). All patients had highly sensitive TSH determination, thyroid hormone levels, radioiodine uptake and scan (except for 2 postpartum women), and, selectively, TSH-receptor antibody (TRAb), serum thyroglobulin, antithyroid antibodies, T3-suppression test, and erythrocyte sedimentation rate. A TSH value of about 0.1 microIU/mL was used as the cutoff. Only one patient in the group had a nonthyroidal disorder. In 14 patients (61%) subclinical hyperthyroidism was self-limited, due to silent thyroiditis (5 patients), iodine-induced hyperthyroidism (3 patients), postpartum thyroiditis (2 patients), subacute thyroiditis (2 patients), and probable hemorrhage into a functioning nodule (2 patients). Of the non-self-limited disorders (39%), Graves' disease accounted for 6 patients and solitary or multinodular goiter for 3. Graves' disease proved difficult to diagnose because the thyroid gland was normal in size in two of the six patients, TRAb was positive in only two of six, and the radioiodine uptake and gradient were normal in all six; the T3-suppression test was positive in two of two patients. We conclude that the causes of subclinical hyperthyroidism are the disorders that commonly produce overt thyrotoxicosis in medical practice, Graves' disease being the most frequent. However, the tests used to diagnose overt Graves' disease often fail in the setting of subclinical hyperthyroidism, except possibly the T3-suppression test.

Low TSH levels in nursing home residents not taking thyroid hormone

BACKGROUND

Many practitioners perform a thyroid stimulating hormone (TSH) assay as a screening test in older patients. The introduction of sensitive TSH assays with lower normal limits has created a laboratory abnormality that is often of uncertain significance. Mechanisms include autonomous overproduction of thyroid hormone, nonthyroidal illness including medication effects, and hypothalamic/pituitary dysfunction.

OBJECTIVE

To characterize the clinical status and course of nursing home residents with low TSH and normal total T4 levels in the absence of treatment with thyroid hormone.

DESIGN

Retrospective chart review was performed to determine participants status at the time of low TSH level, with additional recording of follow-up thyroid hormone levels, cardiac rhythm, and mortality. Mortality was compared with that of a control group matched for age and sex.

SETTING

A nursing home for veterans and their spouses.

MAIN RESULTS

Forty subjects with low TSH and initially normal total T4 were identified. Only three subjects were subsequently diagnosed as hyperthyroid. TSH levels of 18 subjects subsequently normalized, and four additional subjects had low total T3 levels suggesting a nonthyroidal mechanism. Seven subjects died during the first 4 months of follow-up compared with three in a control group (P < .001). Nine of the 40 subjects had a history of or current atrial fibrillation. No new atrial fibrillation was documented during 388 months of EKG follow-up.

CONCLUSIONS

Low total T3 levels, TSH normalization, and excess mortality suggest that nonthyroidal illness plays a role in the pathogenesis of low TSH determinants in the nursing home. Autonomous production of thyroid hormone also plays a role. We believe that the term "subclinical hyperthyroidism" should be used only if the clinician believes that autonomous overproduction of thyroid hormone is the cause of a low TSH level. If subsequent research shows correctable adverse consequences associated with subclinical hyperthyroidism from autonomous overproduction of thyroid hormone, a more aggressive diagnostic approach will be needed to define the mechanism of a low TSH level at the time of its discovery.

Subclinical thyroid disease

Thyroid disease can roughly be divided into functional and anatomical disorders. Subclinical disease is by definition not accompanied by symptoms or signs and usually goes unrecognized for the bearer (and the observer). In this communication an overview will be given of existing literature and some own results concerning subclinical hypothyroidism, subclinical thyrotoxicosis and thyroid incidentalomas. Apart from definitions, data on prevalence, clinical effects, prognostic significance and the need for and response to therapy will be discussed.

Prevalence of sporadic medullary thyroid carcinoma: the importance of routine measurement of serum calcitonin in the diagnostic evaluation of thyroid nodules

OBJECTIVE

The prevalence of sporadic forms of medullary thyroid carcinoma (MTC) has been studied in patients living in an area of moderate iodine deficiency. Such forms of MTC are usually diagnosed after surgery and have little chance of definitive cure. Using the measurement of basal serum calcitonin (CT) levels in a large series of patients with both thyroid disease and normal 24-hour urinary iodine excretion, we assessed the prevalence of MTC and, in patients affected with the disease, we also evaluated the stage of the disease according to surgical findings and post surgical plasma CT levels.

PATIENTS

A prospective study of 657 patients with thyroid disease (469 with nodular and 188 with non-nodular thyroid disease). As controls, 40 normal subjects were also studied.

MEASUREMENTS

In all patients: (1) measurement of basal serum CT, free T4, total T3, TSH levels and serum TSH-receptor, peroxidase and thyroglobulin (Tg) antibody concentrations, (2) thyroid ultrasonography, (3) fine needle aspiration cytology (FNAC). In patients with increased basal CT levels: (1) measurement of serum CT levels during pentagastrin test prior to surgery, (2) histological examination and immunostaining with both anti-CT and anti-Tg antibodies of all the nodular thyroid tissue surgically removed, (3) measurement of basal and pentagastrin stimulated serum CT values after surgery.

RESULTS

All the patients with non-nodular thyroid disease had normal basal CT levels. Four patients (0.84%) with nodular thyroid disease (2 with uninodular and 2 with multinodular goitre) had both elevated basal and pentagastrin stimulated CT levels. In the two patients with uninodular goitre, FNAC was suggestive of MTC in 1 (nodular diameter 8.0 cm) and of follicular carcinoma in 1 (nodular diameter 2.5 cm). Histological examination of the nodules confirmed these histotypes. Immunostaining with anti-CT antibodies was positive in the former patient but also in the latter. FNAC was suggestive of benign adenomatous tissues in the two patients with multinodular goitre. Histological examination of all the thyroid nodules confirmed the cytological findings. However, serial sections through the gland in each of these two patients showed an occult follicular carcinoma which had, however, positive staining with anti-CT antibodies. Furthermore, immunostaining with anti-Tg antibodies was negative in the patient with MTC but positive in the 3 patients with follicular carcinoma. Finally, both basal and pentagastrin stimulated CT levels remained elevated after total thyroidectomy only in the patient with FNAC suggesting MTC.

CONCLUSIONS

This study demonstrates a surprisingly high prevalence of sporadic forms of medullary thyroid carcinoma in patients with nodular thyroid disease. Such forms of medullary thyroid carcinoma seem to be unrelated to iodine intake and may be pure or mixed with a follicular carcinoma. In these mixed thyroid carcinomas, only the neoplastic follicular pattern was seen on both cytological and histological examination. Routine measurements of serum calcitonin levels should therefore be considered an integral part of the diagnostic evaluation of thyroid nodules. Indeed, increasing the accuracy of diagnosis of medullary thyroid carcinoma encourages the surgeon to perform more radical treatment, thus achieving more frequent normalization of post-operative serum calcitonin levels.

Hip fractures and the thyroid: a case-control study

OBJECTIVE

To investigate the prevalence of thyroid illness - especially hyperthyroidism - and exposure to thyroid hormones in patients with hip fracture.

DESIGN

A case-control study.

SETTING

Two surgical/orthopaedic hospital units and 22 facilities for the aged in a moderately iodine-deficient region of Germany.

SUBJECTS

A total of 116 postmenopausal females with hip fracture and 402 postmenopausal female controls.

MAIN OUTCOME MEASURES

Hip fracture; thyroid disease confirmed by measurement of serum thyrotropin, total and free thyroxine and triiodothyronine; history of thyroid disease and thyroid medication obtained by a questionnaire.

RESULTS

Of the hip fracture patients 4.3% had overt untreated hyperthyroidism, and 6.9% gave a history of past hyperthyroidism (total, 11.2%). The corresponding figures for the controls were 2.0 and 2.7%, respectively (total, 4.7%). 7.8% of the cases had been exposed to levo-thyroxine for 3-29 years, compared to 11.2% of the controls. The odds ratio for hyperthyroidism (present and past) was 2.5 (1.2-5.3, 95% confidence interval), and the odds ratio for levo-thyroxine exposure was 0.67 (0.32-1.41) in the hip fracture patients.

CONCLUSIONS

Hyperthyroidism is found 2.5-fold more often in hip fracture patients than in controls. Hence, hyperthyroidism appears to be a significant risk factor for hip fracture and should be investigated by clinical and, when necessary, laboratory means in hip fracture patients. In contrast, no increased risk for hip fracture could be detected after exposure to levothyroxine.

Evidence for the effect of antibodies to TSH receptors on the thyroid ultrasonographic volume in patients with Graves' disease

OBJECTIVE

It has been demonstrated that antibodies (Ab) to thyroid-stimulating hormone receptors (R), which stimulate the thyroid gland, induce hyperthyroidism in patients with Graves' disease. Furthermore, it has been shown in thyroid cells in culture that thyroid-stimulating hormone receptor Ab acts through the adenosine 3', 5'-monophosphate pathway which stimulates both thyroid hormonogenesis and growth. We investigated the relations between thyroid autoimmunity expression and thyroid ultrasonographic parameters or thyroid hormonal status in patients with Graves' disease.

PATIENTS

A prospective study of 53 consecutive patients referred with untreated Graves' disease.

MEASUREMENTS

Measurements were made of serum TSH-R, peroxidase (TPO) and thyroglobulin (Tg) Ab and basal plasma free T4 (FT4), free T3 (FT3) and TSH. Thyroid morphological characteristics (number and total volume of nodule(s), total volume of lobes and total thyroid volume) were determined by ultrasonography.

RESULTS

There were significant correlations (P < 0.001) between TSH-RAb levels and FT4 values (r = 0.48) or FT3 levels (r = 0.46). Likewise, significant correlations were found between TSH-RAb levels and total lobe volume values (r = 0.56, P < 0.001), total nodular volume values (r = 0.59, P < 0.01) or total thyroid volume values (r = 0.63, P < 0.001). By contrast, no correlation was found between TSH-RAb levels and the number of nodules or between any of the ultrasonographic parameters and TPOAb levels or TgAB values.

CONCLUSIONS

This study demonstrates, in vivo, that TSH receptor antibodies modulate the thyroid ultrasonographic extranodular and nodular volumes in patients with Graves' disease.