Endemic goiter and endemic thyroid disorders

Exploring the potential of genetic analysis in historical blood spots for patients with iodine-deficient goiter and thyroid carcinomas in Switzerland and Germany (1929-1989)

Iodine deficiency-induced goiter continues to be a global public health concern, with varying manifestations based on geography, patient's age, and sex. To gain insights into clinical occurrences, a retrospective study analyzed medical records from patients with iodine deficiency-induced goiter or thyroid cancer who underwent surgery at the Community Hospital in Riehen, Switzerland, between 1929 and 1989. Despite today's adequate iodine supplementation, a significant risk for iodine-independent goiter remains in Switzerland, suggesting that genetic factors, among others, might be involved. Thus, a pilot study exploring the feasibility of genetic analysis of blood spots from these medical records was conducted to investigate and enhance the understanding of goiter development, potentially identify genetic variations, and explore the influence of dietary habits and other environmental stimuli on the disease.Blood prints from goiter patients' enlarged organs were collected per decade from medical records. These prints had been made by pressing, drawing, or tracing (i.e., pressed and drawn) the removed organs onto paper sheets. DNA analysis revealed that its yields varied more between the prints than between years. A considerable proportion of the samples exhibited substantial DNA degradation unrelated to sample collection time and DNA mixtures of different contributors. Thus, each goiter imprint must be individually evaluated and cannot be used to predict the success rate of genetic analysis in general. Collecting a large sample or the entire blood ablation for genetic analysis is recommended to mitigate potential insufficient DNA quantities. Researchers should also consider degradation and external biological compounds' impact on the genetic analysis of interest, with the dominant contributor anticipated to originate from the patient's blood.

Ischemic stroke: a rare complication of a large multinodular goiter

Summary

Mass effect from a goiter is a serious complication with potentially life-threatening consequences. In rare instances, a goiter can compress nearby vessels, compromising cerebral blood flow, which can lead to an ischemic stroke. Ischemic strokes generally occur due to atherogenic or embolic phenomenon, albeit a rare etiology can be due to a mechanical obstruction of great vessels of the neck that provide blood supply to the brain. An unusual example of a similar obstruction is the mass effect of an expansive goiter on the carotid artery (CA) in the neck. We present a rare case of a 90-year-old female who had a historically untreated goiter for 13 years. She presented with symptoms of acute stroke, including right-sided weakness and dysarthria. CT angiogram of the neck revealed a massively enlarged thyroid gland causing compression and intermittent obstruction of the blood flow in the left common CA. Subsequently, the patient underwent a total thyroidectomy. Postoperatively, she had a remarkable recovery of her symptoms of right-sided weakness and dysarthria. Acknowledging stroke as a grave mechanical complication of a large multinodular goiter is crucial for timely and appropriate management to avoid serious consequences.

Learning points

The natural history of euthyroid multinodular goiters include abnormal enlargement of the thyroid gland, which results in local compression of structures in the neck causing neurovascular injury. Timely diagnosis and surgical management of an enlarging goiter compressing the CA can reduce morbidity from an ischemic stroke. Ischemic stroke is a rare and dangerous complication of a giant multinodular goiter.

Sonoelastographic Evaluation of Recurrent Thyroid Nodules in Patients with Operated Recurrent Nodular Goiters

Alterations in neck anatomy after thyroid surgery and post-operative fibrosis may be misleading by causing sonoelastographic changes in recurrent tissues in patients with recurrent nodular goiter and so may result in unnecessary biopsies or surgical procedures. Here, the aim was to examine thyroid sonoelastography values in patients developing a recurrence and presenting with recurrent nodular goiter with benign cytology after total or near-total thyroidectomy (T/N-TT). Twenty-nine nodules from 22 patients with a recurrence after T/N-TT whose biopsies were found to be benign constituted the patients, and 23 nodules from 23 participants among the non-operated patients having solitary or multiple thyroid nodules and with age, gender and body mass index values similar to those of the patients constituted our controls. Shear-wave velocity (SWV) values were measured. Average elapsed time after T/N-TT was 11.82 (4:25) y. No difference was detected between the groups in terms of localization and sonographic structures of the nodules. Nodule SWV values were higher in the operated recurrent nodular goiter group than in the controls (2.93 ± 0.87 m/s vs. 2.43 ± 0.33 m/s, respectively, p = 0.011). Because SWV values are high in operated recurrent nodular goiter patients, the utilization of reference sonoelastography values in those with unoperated goiter may yield misleading results in the differentiation of benign and malignant lesions.

Simulation Model for Hashimoto Autoimmune Thyroiditis Disease

Hashimoto thyroiditis (HT) is a pathology that often causes a gradual thyroid insufficiency in affected patients due to the autoimmune destruction of this gland. The cellular immune response mediated by T helper lymphocytes TH1 and TH17 can induce the HT disease. In this pathologic condition, there is an imbalance between the TH17 and Treg lymphocytes as well as a gut microbiota dysfunction. The objective of this work was to describe the interactions of the cell subpopulations that participate in HT. To achieve this goal, we generated a mathematical model that allowed the simulation of different scenarios for the dynamic interaction between thyroid cells, the immune system, and the gut microbiota. We used a hypothetical-deductive design of mathematical modeling based on a system of ordinary differential equations, where the state variables are the TH1, TH17, and Treg lymphocytes, the thyrocytes, and the bacteria from gut microbiota. This work generated a compartmental model of the cellular immune response occurring in the thyroid gland. It was observed that TH1 and TH17 lymphocytes could increase the immune cells' activity, as well as activate effector cells directly and trigger the apoptosis and inflammation processes of healthy thyrocytes indirectly. Likewise, the model showed that a reduction in Treg lymphocytes could increase the activity of TH17 lymphocytes when an imbalance of the gut microbiota composition occurred. The numerical results highlight the TH1, TH17, and bacterial balance of the gut microbiota activities as important factors for the development of HT disease.

Thiocyanate in excess develops goiter followed by auto immune thyroid diseases even after effective salt iodization in a rural community of north east India

PURPOSE

Salt iodization in Manipur of north-east India failed to prevent endemic goiter, therefore an in depth study carried out to evaluate thyroid functions of goitrous subjects in a randomly selected region.

METHODS

Goiter survey conducted in children and women of reproductive ages by palpation followed by measurement of urinary iodine, thiocyanate and house-hold salt iodine to evaluate iodine nutritional status and consumption pattern of bamboo-shoots (BS). In all grade-2 goitrous subjects, free thyroxine, triiodothyronine, TSH, TPO and Tg antibodies, thyroid volume and echogenecity by ultrasonography and cytomorphology of thyroid by FNAC studied.

RESULTS

Study population was 2486 children and 1506 women, goiter prevalence was 12.59% and 16.27% respectively; median urinary iodine and mean thiocyanate were 166 µg/l and 0.729 ± 0.408 mg/dl while salt iodine was ≥30 ppm. Serum thyroid hormones and TSH profiles of all grade-2 goitrous subjects showed 16.21% were subclinically hypothyroid, 2.16% overt hypothyroid, 4.86% subclinically hyperthyroid and 6.48% overt hyperthyroid, serum TPO- and Tg-antibodies found positive in 41.62%. Ultrasonographic results showed 24% had enlarged thyroid and 86.4% hypoechoic. Cytomorphological studies showed prevalence of colloid goiter (41.08%), lymphocytic thyroiditis (37.83%), Hashimoto's thyroiditis (8.10%), autoimmune thyroiditis (4.32%), sub-acute thyroiditis (2.16%) and 1.62% each papillary, medullary carcinoma, simple diffused hyperplasia and adenomoid nodular goiter.

CONCLUSIONS

Grade-2 goitrous individuals in this mild goiter endemic region were affected by hypo- and hyperthyroidism with hypoechoic thyroid and thyroiditis. Thiocyanate that originates from BS even in presence of adequate iodine developed goiter and led goitrous population towards such diseases.

Co-existent Epicardial Paraganglioma and Anterior Mediastinal Thymoma

Thymoma and paraganglioma are known causes of mediastinal masses, the latter being extremely rare. Thymomas arise from remnant thymic tissue in the anterior mediastinum; whereas, thoracic paragangliomas arise from para-aortic or para-vertebral sympathetic chain ganglion (derivatives of embryonic neural crest) in the middle or posterior mediastinum. We report a case of a middle-aged woman with two mediastinal masses, originally believed to be a single tumor or primary malignancy with adjacent metastasis on Computed Tomography (CT) that were further delineated with Magnetic Resonance Imaging (MRI) and [68Ga]-DOTA-(Tyr3)-octreotate (DOTA-TATE) Positron Emission Tomography-Computed Tomography (PET-CT) and surgical pathology as two distinct entities: left epicardial paraganglioma and anterior mediastinal thymoma. A comprehensive discussion of both entities is included.

Patient satisfaction following thyroidectomy in surgical mission: a prospective study

BACKGROUND

Surgical volunteer mission is a well-recognized approach for reducing the burden of surgical disease worldwide. The aim of this study was to evaluate safety and patient satisfaction of thyroid surgery in the context of surgical mission carried out in Bohol Province, Philippines.

METHODS

This was a prospective study involving consecutive patients undergoing thyroid surgery in the surgical mission held in 2018. Informed consent was obtained from the patients. Safety defined as observed serious postoperative complication rate as compared to its expected based on American College of Surgeons National Surgical Quality Improvement Program (NSQIP) was the primary endpoint, whereas patient satisfaction rated on a 5-point Likert scale was the secondary endpoint. Expected serious complication rate was calculated using the surgical risk calculator of NSQIP. Thyroid surgery included partial resections, hemi-, subtotal, and total thyroidectomies.

RESULTS

Thirty-eight patients underwent thyroidectomy performed by 4 surgeons in 2018 mission. Mean age of the patients was 40.6±11.3 years. Male to female ratio was 2:36. Goiter was the indication for surgery in 33 (86.8%) patients, whereas 5 (13.2%) patients were operated for thyroid malignancy. Postoperative serious complication and reoperation occurred in 1/38 (2.6%) for hematoma on first postoperative day. Expected and observed serious complication rates did not differ (1.1% vs. 2.6%; P=0.385). Ninety-seven percent of patients were satisfied with outcomes of surgery.

CONCLUSIONS

This prospective cohort study found thyroid surgery performed within a surgical mission to be safe. Patient satisfaction rate was 97%. Further research is needed to develop and validate patient satisfaction assessment tools in surgical missions.

Frequency of Thyroid Carcinoma in a Recent Series of 539 Consecutive Thyroidectomies for Multinodular Goiter

Aims and background

The aim of the study was to analyze the frequency of thyroid carcinoma in a consecutive series of 539 thyroidectomies for multinodular goiter (MNG) and to assess the influence of sex and age as cancer risk factors.

Methods

In a 2-year period, 539 patients underwent subtotal or total thyroidectomy for MNG at the Institute of General Surgery, University of Padova, Padova, Italy: 455 were females and 84 males (F/M = 5.5/1); mean age was 46 years (min. 17, max 78). Only 17 patients (3.1%) (16 females and 1 male) were aged 21 years or less.

Results

A malignancy was found in 41 patients: 38 females and 3 males; 39 older and 2 younger than 21 years. The frequency of cancer in MNG was 7.6%: 8.3% in females and 3.6% in males; 7.5% in patients older than 21 and 11.7% under 21 years.

Conclusions

The combination of MNG and carcinoma should always be carefully considered but not overemphasized, and the policy of surgically treating all patients with MNG is not justified. Sex and age cannot be considered as factors of a higher risk of cancer.

Thyroid Disease Around the World

Thyroid disease is one of the most common pathologies in the world, with two of the most clinically important subgroups being iodine deficiency and thyroid goiter, and thyroid cancer. This review looks at the current state of thyroid disease in the world and evaluates the future direction in terms of thyroid disease treatment and prevention. Several of the most impactful epidemiologic studies are presented and analyzed, as well as a brief overview of the current socioeconomic burden of disease.

Endocrine disorders and the cerebellum: from neurodevelopmental injury to late-onset ataxia

Hormonal disorders are a source of cerebellar ataxia in both children and adults. Normal development of the cerebellum is critically dependent on thyroid hormone, which crosses both the blood-brain barrier and the blood-cerebrospinal fluid barrier thanks to specific transporters, including monocarboxylate transporter 8 and the organic anion-transporting polypeptide 1C1. In particular, growth and dendritic arborization of Purkinje neurons, synaptogenesis, and myelination are dependent on thyroid hormone. Disturbances of thyroid hormone may also impact on cerebellar ataxias of other origin, decompensating or aggravating the pre-existing ataxia manifesting with motor ataxia, oculomotor ataxia, and/or Schmahmann syndrome. Parathyroid disorders are associated with a genuine cerebellar syndrome, but symptoms may be subtle. The main conditions combining diabetes and cerebellar ataxia are Friedreich ataxia, ataxia associated with anti-GAD antibodies, autoimmune polyglandular syndromes, aceruloplasminemia, and cerebellar ataxia associated with hypogonadism (especially Holmes ataxia/Boucher-Neuhäuser syndrome). The general workup of cerebellar disorders should include the evaluation of hormonal status, including thyroid-stimulating hormone and free thyroxine levels, and hormonal replacement should be considered depending on the laboratory results. Cerebellar deficits may be reversible in some cases.

Access, availability, and infrastructure deficiency: The current management of thyroid disease in the developing world

Thyroid disease, a neglected tropical disease and the most common noncommunicable disease in the developing world, is overlooked, under-diagnosed, and inadequately managed. The spectrum of thyroid disorders in the developing world is qualitatively different from that found in industrialized countries. This qualitative difference has resulted in limited access to clinical, laboratory, and imaging resources that are necessary for the care of patients with thyroid disease. The management of thyroid disease in the developing world is comparable to the care provided for disorders of the thyroid in North America fifty years ago.This article reviews public health and clinical aspects of developing world medical and surgical thyroid disease. Topics covered include iodine deficiency disorders, congenital hypothyroidism, goiter, thyroid cancer, and hyper- and hypothyroidism. The review concludes with a description of programs based on smartphone technology to improve the availability, affordability, and quality of thyroid disease care.

Unanticipated thyroid cancer in patients with substernal goiters: are we underestimating the risk?

BACKGROUND

The rate of unexpected thyroid cancers found at the time of thyroidectomy is thought to be similar in patients with cervical and substernal multinodular goiters (MNGs).

METHODS

The objective of this study was to compare the prevalence of undiagnosed cancer found in patients undergoing a thyroidectomy for a cervical or substernal MNG. We conducted a review of patients with a preoperative diagnosis of an MNG (both cervical and substernal) at a tertiary referral center between 2005 and 2012.

RESULTS

We identified 538 patients who underwent thyroidectomy for an MNG (144 with substernal MNGs and 394 with cervical MNGs). Patients with substernal MNGs were older (59.6 vs. 52.3; p < 0.001), more likely to be men (34 vs. 11.1 %; p < 0.001), and less likely to have a history of radiation exposure to the neck (2.1 vs. 12.4 %; p < 0.001). Thyroid cancer (>1 cm) was found in 13.7 % of substernal MNG specimens and in 6.3 % of cervical MNG specimens (p = 0.003). On multivariate analysis, substernal location [odds ratio (OR) = 2.360; confidence interval (CI), 1.201-4.638] was the only variable independently associated with an unexpected thyroid cancer on surgical pathology.

CONCLUSION

The rate of postoperatively discovered thyroid cancer is significant in patients with substernal MNGs and is increased when compared to patients with cervical MNGs. Surgeons should counsel their patients regarding the possibility of this unexpected result.

Influence of iodization programmes on the epidemiology of nodular goitre

Iodine is essential for the synthesis of thyroid hormones. Iodine deficiency can affect human health in different ways, and is commonly referred to as iodine deficiency disorders (IDD). These range from defective development of the central nervous system during the fetal-neonatal life, to goitre in the adult. Only a few countries were completely iodine sufficient before 1990. Since then, a major effort has been made to introduce salt iodization to ensure sufficient intake of iodine in deficient areas. Iodine prophylaxis has been shown to exert a pivotal role in abating goitre and other iodine-deficiency disorders, and has also been shown to modulate the pattern of thyroid diseases. An increased frequency of thyroid autoimmunity and of hypothyroidism has been observed after introducing iodization programmes. Nevertheless, available evidence clearly confirms that the benefits of correcting iodine deficiency, consisting mainly of reducing nodular goitre and non-autoimmune hyperthyroidism, far outweigh the risks of iodine supplementation.

Current role and value of fine-needle aspiration in nodular goitre

Thyroid nodules are common and, depending on the detection technique used, can affect 50% or greater of the population. The primary diagnostic test to assess the nature of these nodules is fine-needle aspiration cytology. Most thyroid nodules are benign and often are multiple. However, the morphology of these nodules may mimic neoplasms showing features such as papillary growth, micro-follicles and even oncocytic metaplasia. Lesions with these features may be considered indeterminate for neoplasm or malignancy, and often require surgical excision to define their nature. The role of cytopathology in this area is to screen those definitely benign nodules, thus preventing surgery and reassuring both the patient and the clinician. In this review, we demonstrate many of the morphological manifestations of nodular goiter and stress the necessity of careful preparatory techniques. Although the past several years have witnessed the development of molecular testing to refine diagnostic cytology in the thyroid, it is still the role of the cytopathologist to identify those "indeterminant" nodules which should be tested. Thus, the cytopathologist contributes both an essential diagnostic and an important cost saving role which hopefully will continue in the future.

Surgical treatment of endemic goiter in a nonhospital setting without general anesthesia in Africa

BACKGROUND

Endemic goiter remains a serious public health problem and 75 % of people affected live in underdeveloped countries where treatment is difficult for various reasons. The aim of this article is to report our experience in African countries with the management and surgical treatment of endemic goiter, performed in a nonhospital setting and without general anesthesia in the context of a collaborative development project by experienced endocrine surgeons.

METHODS

Fifty-six black African patients with a goiter were studied. Those in poor general health, the elderly, patients with either small goiters or clinical hyperthyroidism, and those presenting with an acute episode of malaria were excluded from the study. Cervical epidural anesthesia with spontaneous ventilation was used and a partial thyroidectomy was performed. The technique used, its immediate complications, and early and late follow-up were analyzed.

RESULTS

Surgery was performed on 31 patients with grades 3 and 4 goiter without mortality and a morbidity rate of 11.9 %, with 97 % of all complications being minor. There were no instances of dysphonia or symptomatic hypocalcemia and the mean stay was 1.57 days (range 1.25-1.93). Follow-up in the first year was 71 % and no case of severe or recurrent hypothyroidism was detected.

CONCLUSIONS

Surgery without general anesthesia performed in a nonhospital setting in underdeveloped countries in patients with goiter is a viable option with good results and low morbidity.

Risk factors for anaplastic thyroid cancer

Background. Anaplastic thyroid cancer (ATC) is a form of thyroid cancer with very poor prognosis, but is fortunately quite rare. Its aetiology is unknown and not well researched. Aim. The aim of this study was to identify potential risk factors for ATC. Material and Method. Case-control study of 126 ATC patients (77 females and 49 males) and 252 controls individually matched by gender, age, and place of abode. In statistical analysis we used a Cox regression model. Results. Univariate logistic regression showed that the risk factors for ATC are low education level, type B blood group, goitre, other nonthyroid malignancies, diabetes, late menarche, and an early first pregnancy. Multivariate logistic regression analysis showed that independent risk factors for ATC are low education level (OR = 1.42, 95% CI = 1.09-1.86), type B blood group (OR = 2.41, 95% CI = 1.03-5.66), and goitre (OR = 25-33, 95% CI = 5.66-126.65). Conclusion. Independent risk factors for ATC are: low education level, type B blood group, and goitre.

Hypothyroidism, new nodule formation and increase in nodule size in patients who have undergone hemithyroidectomy

INTRODUCTION

The current medical literature has conflicting results about factors related to hypothyroidism and nodular recurrences during follow-up of hemithyroidectomized patients. We aimed to evaluate factors that may have a role in new nodule formation, hypothyroidism, increase in thyroid lobe and increase in nodule volumes in these patients with and without Hashimoto's thyroiditis (HT), and with and without levothyroxine (LT4) use.

MATERIAL AND METHODS

We enrolled 140 patients from five different hospitals in Ankara and evaluated their thyroid tests, autoantibody titre results and ultrasonographic findings longitudinally between two visits with a minimum 6-month interval.

RESULTS

In patients with HT there was no significant difference between the two visits but in patients without HT, thyroid stimulating hormone (TSH) levels and nodule volume were higher, and free T4 levels were lower in the second visit. Similarly, in patients with LT4 treatment there was no difference in TSH, free T4 levels, or lobe or nodule size between the two visits, but the patients without LT4 had free T4 levels lower in the second visit. Regression analysis revealed a relationship between first visit TSH levels and hypothyroidism during follow-up.

CONCLUSIONS

Patients who have undergone hemithyroidectomy without LT4 treatment and without HT diagnosis should be followed up more carefully for thyroid tests, new nodule formation and increase in nodule size. The TSH levels at the beginning of the follow-up may be helpful to estimate hypothyroidism in hemithyroidectomized patients.

Urine iodine excretion ın patients with euthyroid noduler disease

BACKGROUND AND OBJECTIVES

Different nutritional and environmental factors are responsible for the pathogenesis of goiter, but iodine deficiency is the most important factor. However, little is known about the natural course of benign thyroid nodules in euthyroid patients over time. Few studies have used ultrasonographic evaluation to address this issue, especially in iodine-deficient areas. In this study, we present the long-term follow-up of benign thyroid nodules in a iodine-deficient area.

DESIGN AND SETTING

Cross-sectional study at a tertiary referral center.

PATIENTS AND METHODS

This study included 62 randomly selected patients with benign euthyroid nodule. Thyroid volume and nodules were measured with sonography. Iodine intake was estimated by patient diet history and by measuring iodine excretion in spot urine samples. Patients were followed one year.

RESULTS

Patients were divided into three groups according to level of urine iodine excretion: Group 1: <50 μg/L (severe iodine deficiency group), Group 2: 50-100 μg/L (mild iodine deficiency group), Group 3: >100 g/L (iodine sufficient group). The presence of additional disease (hypertension, diabetes mellitus, coronary heart disease, chronic renal failure and a history of any medication for chronic disorder) and smoking rates were significantly higher in first group compared to the second and third group. Among groups, no significant difference was observed in either right or left thyroid lobe volume after one year. A clinically significant increase in nodule volume was observed in the first group, while there was a significant decrease in the second and third group.

CONCLUSION

In this study, iodine deficiency was associated with an increase in thyroid nodule volumes. Smoking rates were higher in iodine deficient groups. It is thought that smoking impairs iodine intake or absorption consistent with a previous report.

Thyroid surgery in Burkina Faso, West Africa: experience from a surgical help program

BACKGROUND

Endemic goiter caused by iodine deficiency is still very common in sub-Saharan Africa and is a surgical challenge because of the often large size of the goiters.

METHODS

A retrospective analysis was made of patients who underwent operation for thyroid diseases during a surgical help program in Leo/Burkina Faso during a 7-year period from 2001 to 2008.

RESULTS

A total of 253 cases presented with goiters grade III (WHO classification) were operated on: 134 hemithyroidectomies, 108 hemithyroidectomies combined with subtotal contralateral resection, and 11 total thyroidectomies were performed. The recurrent laryngeal injury rate was 0.8%, and the re-exploration rate for bleeding was 1.2%. Median hospital stay was 3.1 days. Histological examinations showed Graves' disease in 6 cases, and multinodular goiter in 231 cases. Follicular cancer was found in 15 cases, and anaplastic carcinoma was found in 1 case.

CONCLUSIONS

Thyroid surgery can be performed with low complication rates under basic surgical conditions. Because of the size and pathology of the goiters, total thyroidectomy is the method of choice. However, considering the risk of the development of hypothyroidism due to poor understanding or difficult access to medication, a limited resection, e.g., hemithyroidectomy, is the most optimal operative strategy.

Etiological factors for the persistence of endemic goiter in selected areas of Siddharthnagar district in Eastern Uttar Pradesh, India

AIM

To assess the prevalence of goiter, state of iodine nutrition of the population, consumption pattern of common goitrogenic food, and distribution of iodine through edible salt in selected CD Blocks of Siddharthnagar district in Eastern Uttar Pradesh.

METHODS

Goiter survey among 1,862 school children, aged 6-12 years, of both sexes, and analysis of iodine (I) and thiocyanate (SCN) in 240 urine samples, and iodine content in 210 edible salt samples collected from the selected study areas.

RESULTS

The prevalence of goiter was 26.3% (grade 1: 23.2%; grade 2: 3.1%). Median urinary iodine level was 6.0 microg/dl, and 42% had concentration < 5 microg/dl. Mean (SD) urinary SCN was 0.75 (0.4) mg/dl. Only17.1% of salt samples had iodine level > 15 ppm; 82.9% had < 15 ppm.

CONCLUSION

Consumption of inadequately iodized salt and cyanogenic plant foods containing goitrogenic/anti-thyroidal substances by the people of the studied region are possible reasons for the persistence of goiter during the post salt iodination phase.

Levothyroxine therapy in preventing nodular recurrence after hemithyroidectomy: a retrospective study

AIM

To determine the effect of levothyroxine (L-T4) therapy on the recurrence rate of nodular disease in patients previously treated with lobectomy for benign nodular goiter.

METHODS

Two hundred and thirty-tree patients (38 males, 195 females; age 49.9+/-13.1 yr) with no post-surgical evidence of nodular disease in the remnant, were followed- up yearly with serum TSH and ultrasound (US). Nodular recurrence was defined as a lesion of at least 5 mm at US. Patients were divided in 2 groups based on whether or not they had been treated with L-T4 after surgery: Group 1 (45 patients) who did not receive any L-T4, and Group 2 (188 patients) treated with L-T4. Group 2 was further subdivided in Group 2a (123 patients) receiving L-T4 substitutive therapy (TSH>or=0.5 and <or=3 mUI/l) and Group 2b (65 patients) receiving L-T4 at TSH-suppressive dose (TSH<0.5 mUI/l).

RESULTS

Mean observation period was 5.8+/-4.7 yr. Overall, 71 out of 233 (30.5%) patients experienced recurrence of thyroid nodular disease: 29 patients (64.4%) in Group 1, 24 (19.5%) patients in Group 2a, and 18 (27.7%) patients in Group 2b. The recurrence rate was significantly lower (p<0.001) in Group 2 compared with Group 1, but no significant difference was observed between Groups 2a and 2b.

CONCLUSION

In patients who have undergone hemithyroidectomy for benign monolobar nodular disease, L-T4 therapy may prevent recurrence of nodular disease. TSH suppression may not be required for prevention of recurrence in the remnant thyroid tissue.

Case-control study of anaplastic thyroid cancer: goiter patients as controls

Anaplastic thyroid cancer is very serious disease with bad prognosis and unknown etiology. The aim of the study was to test some hypotheses about other factors in addition to goiter related to anaplastic thyroid cancer occurrence. A case-control study was performed during the period 1993-2005. The case group comprised 126 patients with newly diagnosed anaplastic thyroid cancer. The control group comprised 252 patients who had for the first time goiter operation, and had no malignancy of thyroid gland. Cases and controls were individually matched by age, sex and place of residence (urban/rural). According to conditional multivariate logistic regression analysis, anaplastic thyroid cancer was significantly related to lower education (odds ratio=1.85, 95% confidence interval=1.21-2.82), other malignant tumors in personal history (odds ratio=4.37, 95% confidence interval=1.11-17.31), blood group B (odds ratio=3.69, 95% confidence interval=1.10-12.49), menarche at >or=15 years of age (odds ratio=2.63, 95% confidence interval=1.15-5.88), and first full-term pregnancy before 19 years of age (odds ratio=2.96, 95% confidence interval=1.26-6.96). On the basis of the results obtained, risk factors for anaplastic thyroid cancer are similar to risk factors for differentiated thyroid cancers.

Fate of the non-operated, non-toxic goitre in a defined population

BACKGROUND

There is lack of consensus in Europe regarding the management of patients with benign goitre. This study evaluated the long-term results of recommending no surgery for clinically and cytologically benign goitre.

METHODS

Some 261 patients (median age 56 years) referred for surgical evaluation for goitre were followed prospectively for a median of 130 months. All hospital and primary care charts were reviewed and living patients interviewed by telephone.

RESULTS

During follow-up, 36.4 per cent of patients were re-referred for a new surgical evaluation, mainly because of growth of the goitre and/or worsening of local symptoms. Fifty-seven (21.8 per cent) of the patients had surgery, and 13 developed thyrotoxicosis. Five patients (1.9 per cent) were diagnosed with thyroid carcinoma, three of whom (all elderly women) died from the disease. Some 95.0 per cent of patients were satisfied with the expectant policy, but 13.1 per cent had been worried about thyroid cancer despite the reassurance of a benign diagnosis.

CONCLUSION

Patients with benign goitre can be treated conservatively with good results. However, there is a small risk that aggressive carcinoma will develop and about a quarter of patients may need surgery within 10 years of the decision to wait and see.

A survey of urinary iodine concentration in south-east of Caspian Sea in northern, Iran

The objective of this study was to evaluate the urinary iodine concentration in Gorgan located in northern Iran, which is a cosmopolitan society and on the basis of such determination the endemic goiter in the region could be estimated. The sample population were a total of 287 people (23.3% male, 76.7% female) referred to Danesh Medical Diagnostic Laboratory for the urinary iodine measurement, during 2004-05. Urinary iodine level was determined using acid digestion method. The results from this study indicated that 2.1, 3.8 and 9.8% of sample population had urinary iodine level of <2, 2-4.9 and 5-9.9 microg dL(-1), respectively which are defined as sever, moderate and mild iodine deficiency. Therefore 45 (15.7%) of the sample population in this study could be assessed for goiter prevalence, the mean differences of iodine concentration in male and female subjects were not significant. In conclusion, low urinary iodine of <10 microg dL(-1) concentration may help to give a direction for a further examination in the thyroid gland abnormalities.

[Effects of inorganic nitrates on thyroid gland activity and morphology in female rats]

The present study was undertaken to determine the effects of intake of inorganic nitrates in drinking water on thyroid gland activity and morphology in female rats. During 5 months of treatment, nitrates 50, 150 and 500 mg/L induced a significant dose-dependent decrease in bodyweight gain, compared with the control rats. At the end of the experiment, nitrates 150 and 500 mg/L induced hypertrophy of the thyroid gland, accompanied by an increase in the size of the thyroid follicles and hyposecretion of thyroid hormones T3 (triiodothyronine) and T4 (tetraiodothyronine). We concluded that a high nitrate intake in water influenced thyroid gland activity and morphology and might be considered to be a goitrogenic factor.

[Clinical recurrence of multinodular goiter after surgery. A multivariate study on the risk factors]

INTRODUCTION

In multinodular goiter there is no consensus on which is the most adequate surgical technique, since although the techniques with partial resection show lower risk of complications they are associated with a higher risk of recurrences. The objective of this study is to define the risk factors for recurrence of multinodular goiters after surgery in a series with a mean postoperative follow-up higher than 12 years.

PATIENTS AND METHOD

231 multinodular goiters with partial thyroid surgery are analyzed. The recurrence is assessed through clinical exploration, and is confirmed with echography. The variables analyzed are age, sex, family history of thyroid pathology, residence in goitrogenic areas, asymptomatic hyperthyroidism, compression syndromes, intrathoracic extension of goiter, surgeon experience with endocrine surgery, weight of the thyroid, and surgical technique, chi2 test, Student's t test and a logistic regression test are applied.

RESULTS

After a mean postoperative follow-up of 152 +/- 71 months 67 goiters (29%) showed recurrence with a mean time for recurrence of 85 +/- 67 months. Risk factors detected in the multivariate study were youngest age, surgeon's lack of experience in endocrine surgery, and the surgical technique. Forty-six patients (69%) were operated because of recurrence, most of them by surgeons experienced in endocrine surgery. Thyroidectomy was completed in all cases, and two definitive postoperative complications occurred.

CONCLUSIONS

The index of clinical recurrences is high and increases with the progression; primary risk factors are age, surgeon's experience, and surgical technique. The implication is that partial resection techniques should be carried out by surgeons with experience and there should be avoided in young patients.

Total versus subtotal thyroidectomy for the management of benign multinodular goiter in an endemic region

BACKGROUND

Because controversy still continuous to surround use of total thyroidectomy for the management of benign multinodular goiter, the present study aims to prospectively compare the safety and efficacy of total thyroidectomy with subtotal thyroidectomy.

METHODS

A total of 200 consecutive patients with benign multinodular goiter were assigned to have either total thyroidectomy (n = 105) or subtotal thyroidectomy (n = 95) based on preoperative evaluation, intraoperative macroscopic findings and nodular dissemination. The patients with no healthy tissue or nodules localized in the dorsal part of the gland, which are usually left during normal subtotal resection, were assigned to the total thyroidectomy group. Demographic details, biochemical findings, indications for operation, operating time, specimen weight, complications and hospital stay were noted.

RESULTS

There was no significant difference in the sex, hormonal status or duration of goiter between the two groups (P = 0.74, P = 0.59 and P = 0.59, respectively). The mean operating time was longer (148.52 min +/- 51.10 vs 135.10 min +/- 32.47, P = 0.03), and the mean weight of the specimens was greater (228.40 g +/- 229.91 vs 157.01 g +/- 151.23, P = 0.01) for total rather than subtotal thyroidectomy. Either temporary recurrent laryngeal nerve (RLN) palsy or hypoparathyroidism occurred in 10 (9.3%) or 12 (11.4%) of the patients undergoing total compared with six (6.3%) or nine (9.5%) of the patients undergoing subtotal thyroidectomy (P = 0.40 and P = 0.65, respectively). Either permanent RLN palsy or hypoparathyroidism was observed in one patient undergoing total thyroidectomy (P = 0.34 for each comparison). The mean hospital stay was longer in the total thyroidectomy group (2.24 days +/- 1.18 vs 1.89 days +/- 0.72 for subtotal thyroidectomy, P = 0.01).

CONCLUSIONS

The present study shows that total thyroidectomy can be performed without increasing risk of complication, and it is an acceptable alternative for benign multinodular goiter, especially in endemic regions, where patients present with a huge multinodular goiter.

Predictive factors for recurrence after thyroid lobectomy for unilateral non-toxic goiter in an endemic area: Results of a multivariate analysis

BACKGROUND

The aim of the study was to identify the factors that are predictive of recurrence after thyroid lobectomy for unilateral non-toxic thyroid goiter in an endemic region through a multivariate analysis.

METHODS

Two hundred sixty-eight consecutive patients who underwent thyroid lobectomy and who were evaluated by the same endocrinologist were included. Univariate and multivariate analysis analyzed the relationship between sex, age, preoperative thyroid-stimulating hormone, duration of disease, duration of levothyroxine (LT4) preoperative therapy, cytologic results, histologic results, resected thyroid weight, numbers and diameters of thyroid nodules, morphologic alterations of the remnant lobe, follow-up length, postoperative LT4 therapy, ultrasonographic evidence of recurrence, and reoperation.

RESULTS

The incidence of recurrence was 33.9% (91/268 patients) after a mean follow-up time of 79.9 months (range, 12-251 months), female sex ( P = .016), multiple nodules ( P = .017), and lack of postoperative LT4 therapy ( P = .0009) were predictive factors of recurrence. Reoperation was performed in 20 patients (7.4%); factors that were predictive of reoperation were the presence of multiple nodules ( P = .008), resected thyroid weight ( P = .00006), and lack of postoperative hormonal therapy ( P = .0005).

CONCLUSIONS

Thyroid lobectomy for unilateral non-toxic goiter, when combined with suppressive or substitutive thyroxin therapy, resulted in a low rate of recurrence and reoperation in an endemic area.

Iodized salt improves the effectiveness of L-thyroxine therapy after surgery for nontoxic goitre: a prospective and randomized study

OBJECTIVE

To investigate whether the addition of iodized salt to daily diet in thyroidectomized patients for nontoxic goitre could influence the effectiveness of nonsuppressive L-thyroxine (L-T4) therapy on thyroid remnant size, during 12 months' follow-up after thyroid surgery.

DESIGN AND PATIENTS

A consecutive series of selected 139 patients (26 males, 113 females; median age 45 years, range 30-69 years) living in a moderate iodine-deficient area, and undergoing thyroid surgery for nontoxic multinodular goitre, was enrolled. Patients were assigned randomly to two different therapeutic regimens: 70 patients received L-T4 therapy alone (Gr. L-T4), while the remaining 69 patients took iodized salt on a daily basis in addition to L-T4 treatment (Gr. L-T4 + I). In both groups, the initial L-T4 dose was 1.5 microg/kg/day, which, in our experience, has been shown to be intermediate between suppressive and replacement doses. To avoid the risks of mild thyrotoxicosis and to limit the excessive TSH stimulation of the thyroid remnant, the L-T4 dose was adjusted in those patients with serum TSH levels outside the lowest two-thirds of the normal range (0.3-2.5 mU/l). An ultrasound evaluation of thyroid remnant size was performed after thyroid surgery and 12 months later.

RESULTS

After surgery, the median thyroid remnant volume was 3.5 ml (range 0.4-13.9 ml) in Gr. L-T4 and 4.6 ml (range 0.5-12.7 ml) in Gr. L-T4 + I (P = 0.06). After 1 year of follow-up, the patients treated with L-T4 + I obtained a remnant volume reduction (-39.7%, range -87.0% to +91.2%) significantly (P = 0.006) greater than that observed in patients assuming L-T4 alone (-10.2%, range -89.4% to +85.0%). However, the percentage of patients showing an increase in remnant size in the months following surgery was higher in Gr. L-T4 than in Gr. L-T4 + I (22/60 vs. 9/66; P = 0.01). In Gr. L-T4 patients the thyroid remnant volume variation throughout 12 months of treatment was correlated significantly with the size of the thyroid remnant found at the first ultrasound evaluation (R(2) = 0.3; P < 0.001). No such correlation was found in Gr. L-T4 + I patients, for whom the therapy maintains a similar effectiveness in patients with either a large or a small postsurgery thyroid remnant. In patients treated with L-T4 alone, the remnant volume variation was correlated significantly with the median serum TSH values attained in the course of treatment (R2 = 0.4; P < 0.001). The highest reduction in remnant volume was observed only by lowering the serum TSH concentrations. In patients treated with L-T4 plus iodine, instead, the thyroid remnant volume reduction occurred independently of the plasma TSH levels attained in the course of treatment.

CONCLUSIONS

Our short-term prospective and randomized study leads us to conclude that, in patients living in a moderate iodine-deficient area and undergoing thyroid surgery for nontoxic goitre: (1) the iodine prophylaxis improves the effects of postsurgery nonsuppressive L-T4 therapy on thyroid remnant size. (2) In patients treated with L-T4 alone the therapeutic effectiveness decreases in the presence of a large postsurgery thyroid remnant. With the addition of iodine, the L-T4 maintains a similar efficacy in patients with either a large or a small remnant. (3) During treatment with L-T4 alone the highest therapeutic effectiveness is attained by lowering the plasma TSH concentration. With the addition of iodized salt to the daily diet the effects of L-T4 on remnant size are relevant independently of the TSH levels.

Dietary supplies of iodine and thiocyanate in the etiology of endemic goiter in Tripura

In the post-salt iodization phase, a study on iodine nutriture status was conducted in Tripura of North East India. The clinical variable of the study was goiter and the biochemical variables were urinary iodine and thiocyanate. Random sampling methodology was followed for selecting the study areas in the State. In each study area, the studied population consisted of school children of both sexes in the age group 6-15 years. The total study areas were 22 and the total number of the population was 10,801. The total number of urine samples were analysed for iodine and thiocyanate were 1,032 (about 10%). The total goiter rate was 21.63%. Population of most of the studied areas had no biochemical iodine deficiency as evidenced by median urinary iodine excretion levels. However, the per capita consumption of iodine of about 40% population was inadequate. A large number of cyanogenic plants (SCN precursors) are used as common vegetables. This study ensures that the existing goiter prevalence in the region could possibly due to non-uniform adequate iodine supply along with the thiocyanate load.

Postintervention serum TSH levels may be useful to differentiate patients who should undergo levothyroxine suppressive therapy after thyroid surgery for multinodular goiter in a region with moderate iodine deficiency

Recent studies have raised doubts about the efficacy of the postoperative use of levothyroxine (LT4) suppressive doses in patients who underwent thyroid surgery for multinodular goiter. The purpose of this retrospective study was to examine the efficacy of different doses of LT4 in preventing postsurgical recurrences of simple multinodular goiter and to identify a marker that could be useful in discriminating patients with a higher risk of developing recurrence. Two hundred thirty-two patients (57 male, 175 female) operated for nontoxic multinodular goiter were divided into two groups: (I) patients with normal postsurgery thyrotropin (TSH) levels (0.25 to 4.5 mU/L) and (II) patients with elevated postsurgery TSH levels (>4.5 mU/L). All patients were subjected to replacement (1.3 microg LT4/kg/day) or suppressive (1.7 microg LT4/kg/day) doses of LT4, and they were followed for a median period of 6 years (range 2 to 12). No statistical difference was found for sex, age, and postsurgery serum TSH between patients submitted to suppressive and replacement therapy. The ultrasound (US) detection of new postsurgery nodules of at least 0.5 cm maximum diameter was considered a recurrence of disease and was found in 10% of the cases studied. Patients with normal postsurgery serum TSH showed a high recurrence rate (30.4%) when submitted to lower daily doses of LT4. In patients with elevated postsurgery serum TSH, the rate of nodular goiter recurrence did not vary with different types of LT4 therapy. In conclusion, our results suggest that the postsurgical serum TSH is useful for prediction of nodular goiter recurrence, as it reflects the amount of residual functioning thyroid tissue in the cervical area. It may also be indicative of patients who might benefit from LT4 suppressive therapy.

Goiter recurrence in patients submitted to thyroid-stimulating hormone suppression: possible role of insulin-like growth factors and insulin-like growth factor-binding proteins

BACKGROUND

It is known that factors other than thyroid-stimulating hormone, such as insulin-like growth factor-I (IGF-I) and epidermal growth factor, have a goitrogenic effect. It has been established that insulin-like growth factor-binding proteins (IGFBPs) may play a role as autocrine/paracrine factors in regulating the local actions of IGFs. Both an inhibitory and a stimulatory effect for different IGFBPs have been shown in several cell systems. The aim of this study was to assess the involvement of IGFBPs in the goitrogenic process in patients with goiter recurrence.

METHODS

The IGFBP-1 and -3 content in normal and nodular tissues obtained at the time of thyroidectomy from 10 patients with recurrent goiters, unresponsive to thyroid-stimulating hormone suppressive therapy, was studied. In all patients, a fragment of normal tissue was also obtained. The IGF-I, IGFBP-1, and -3 content was evaluated by specific immunoassays and/or immunoblotting with anti-IGFBP specific antiserum.

RESULTS

The IGF-I content was significantly higher (P < .05) in nodular tissues (8.0 +/- 1.6 ng/g of tissue) than what was found in normal tissue (4.8 +/- 0.9 ng/g). Radioimmunoassay IGFBP-3 concentration in nodular tissue was 111.5 +/- 18.2 ng/g significantly higher (P < .001) than values found in normal tissue (77.5 +/- 18.6 ng/g). By immunoblot, IGFBP-1 appeared higher in all but 1 nodular tissue.

CONCLUSIONS

These data raise the possibility that IGFBPs are important in the proliferative activities entailed in the goitrogenic process. Three mechanisms are potentially involved: (1) reduction of the potency of locally produced IGF peptide to downregulate type I receptors (potentiating effect on the autocrine/paracrine mitogenic action of IGFs); (2) increase of the IGF-I tissue concentration restraining its passage to circulation; and (3) protection of IGF-I from degradation. Further studies are needed to define a more precise link between these factors and the recurrence of goiter.

Sonomorphologic evaluation of goiter in an iodine deficiency area in the Ivory Coast

OBJECTIVES

This study evaluated the extent of thyroid abnormalities in a remote iodine-deficient area of the Ivory Coast.

METHODS

Ultrasonography was used in detecting the presence of goiter.

RESULTS

The overall prevalence rates of goiter were 64.7% among females and 53.3% among males. In children aged 6 to 15 years (n = 314), the prevalence of goiter was 62% regardless of sex. Thyroid volume increased steadily with age, with significantly larger goiters in women 25 years and older. Frequency of cysts and calcifications did not correlate with sex.

CONCLUSIONS

Especially in developing countries, prophylaxis of iodine deficiency disorders must be improved in iodine-deficient areas to prevent substantial morbidity, which is more severe in women and elderly persons.

Thyroid cryotherapy in an experimental rat model

In recent years cryotherapy has been more and more frequently used for the treatment of tumors of different organs. Until now, the use of cryotherapy for the treatment of thyroid lesions, as well as histopathologic changes in thyroid tissue after cryotherapy, has not been described. Nitrous oxide cryotherapy of one thyroid lobe in twenty 12-week male Wistar rats was performed. After 2 and 4 weeks, the cryotreated thyroid lobe and the second lobe along with a part of the trachea, esophagus, and the subhyoid muscles adhering to the thyroid were excised and assessed macro- and microscopically. The macroscopic evaluation, performed 2 and 4 weeks postcryotherapy, revealed atrophy of the cryotreated lobe in 4 and 3 rats, respectively, and reduction of the cryotreated lobe dimensions in 6 and 7 rats, respectively. In the specimens of the lobes excised 2 weeks following cryotherapy, examined microscopically, necrosis, granulomatous inflammation, hemorrhages, and hemosiderin deposits were found most often, whereas in the specimens of the lobe excised after 4 weeks lymphocytic inflammation and fibrosis were mainly observed. No microscopic changes were observed in the thyroid lobes that were not frozen or in the parathyroid glands located inside these lobes or extrathyroidally, either ipsilaterally or contralaterally to the cryotreated thyroid lobes. There was no microscopic damage to other tissues adjacent to the thyroid gland. No rat developed vocal cord dysfunction after cryotherapy and no significant changes in serum calcium level before and after cryotherapy were observed. The results obtained show that it is possible to cryoblate thyroid tissue without damaging the tissues adjacent to the thyroid, as well as to spare function of the recurrent laryngeal nerves and parathyroid glands.

Long-term action of potassium bromide on the rat thyroid gland

Male rats fed by a standard diet with determined of bromine and iodine content were exposed to a 133-day oral administration of KBr (100, 200, 400 mg Br-/l drinking water). Their thyroid glands showed increased growth of the epithelial cells reflected by a microfollicular rearrangement of the parenchyma due to proliferation of very small follicles with a low or zero content of colloid. Morphometric analysis of thyroids of Br(-)-exposed animals revealed a significant decrease in the volume of intrafollicular colloid and marked increase in the number of the smallest follicles (areas up to 100 and 100-300 micron 2). In addition, the nuclei of thyrocytes showed an increased number of mitoses. The vascularization was increased as well. In the blood plasma of the Br(-)-exposed animals the T4 concentration was significantly decreased in dependence on the bromine concentrations. Thyroglobulin immunoreactivity in the colloid of Br(-)-exposed animals decreased after administration of 400 mg Br-/l drinking water. Increasing concentrations of Br- in the drinking water caused an increased bromine concentration in the thyroid, a decreased iodine content and a decreased I/Br molar ratio. The changes in the rat thyroid caused by long-term administration of 100 mg Br-/l were similar to hyperplastic parenchymal goitre and were comparable to those induced in previous experiments by the same bromine concentration administered over a 16- and 66-day period respectively.

Combined impairment of nutritional parameters and thyroid homeostasis in mildly iodine-deficient children

The relation between thyroid homeostasis and the biochemical parameters of subclinical protein malnutrition has been analyzed in schoolchildren in a rural area in the south of Italy, known to be moderately iodine-deficient. The sera of 32 children (15 males and 17 females aged 6 to 11 years) have been analyzed. These children were divided into two groups, according to thyroid function: (1) 16 euthyroid children (mean thyrotropin [TSH] 2.38 +/- .35 mU/L; 6 with goiter) and (2) 16 subclinical hypothyroid children (mean TSH 7.32 +/- 1.68 mU/L; 6 with goiter). Retinol circulating complex (RCC) components were determined in serum by high-performance liquid chromatography (HPLC) and radial immunodiffusion and the essential and nonessential amino acid levels by ion exchange chromatography. Reduced retinol binding protein (RBP) and transthyretin (TTR) levels were recorded in the sera of 11 of 32 (34%) and in 5 of 32 (16%) patients, respectively. The linear regression analysis revealed that RBP and TSH levels were inversely correlated (r = -0.514; p < 0.0026). The RBP levels were subnormal in 2 of 16 euthyroid and in 9 of 16 hypothyroid patients (Fisher test p < 0.023), and the mean RBP levels were significantly reduced in the hypothyroid patients when compared with those of the euthyroid group (p < 0.0026). The retinol/RBP ratio was also significantly different between euthyroid and hypothyroid children (0.75 vs. 0.95; p < 0.0002). The mean essential amino acid levels, with the exception of methionine, were all in the normal range. The selected amino acid ratios confirmed that the patients were exposed to mild protein malnutrition. These results provide evidence that even mild protein-energy malnutrition may have detrimental effects on thyroid homeostasis in iodine-deficient areas.

Expression of the proliferating cell nuclear antigen (PCNA) in the rat thyroid gland after exposure to bromide

Analysis of expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats fed by a standard diet with determined iodine and bromine content were given potassium bromide. Control animals received no bromide. Experimental animals were given 10, 50 or 100 mg Br- per 11 drinking water for 16 and 66 days, or 100, 200, 400 mg Br-/l drinking water for 133 days. The thyroids of treated animals showed activation of growth of the epithelial follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/l drinking water). Using the PCNA-LI index (PCNA-positive nuclei.100/total number of follicular cell nuclei in the section), immunohistochemical analysis of PCNA in the nuclei of the follicular cells was carried out in parrafin sections. The index was significantly higher in bromide exposed animals (P < 0.01) and correlated well with the histological changes, with bromide concentration and with a increased mitotic activity of the follicular cells. PCNA analysis showed that morphological changes resembling a parenchymatic goitre reflect a microfollicular rearrangement of the thyroid of rats exposed to bromide and have the character of hyperplasia owing to the increased mitotic activity of the follicular epithelium.

Infant survival is improved by oral iodine supplementation

Although reports suggest that infant mortality is increased during iodine deficiency, the effect of iodine supplementation on infant mortality is unknown. A double-masked, randomized, placebo-controlled, clinical trial of oral iodized oil was conducted in Subang, West Java, Indonesia to evaluate the effect of iodine supplementation on infant mortality. Infants were allocated to receive placebo or oral iodized oil (100 mg) at about 6 wk of age and were followed to 6 mo of age. Six hundred seventeen infants were enrolled in the study. Infant survival was apparently improved, as indicated by a 72% reduction in the risk of death during the first 2 mo of follow-up (P < 0.05) and a delay in the mean time to death among infants who died in the iodized oil group compared with infants who died in the placebo group (48 days vs. 17.5 d, P = 0.06). Other infant characteristics associated with reduced risk of death included weight-for-age at base line, consumption of solid foods, female gender and recent history of maternal iodine supplementation. Oral iodized oil supplementation had a stronger effect on the mortality of males compared with females. This study suggests that oral iodized oil supplementation of infants may reduce infant mortality in populations at risk for iodine deficiency.

Risk of thyroid nodules in subjects occupationally exposed to radiation: a cross sectional study

OBJECTIVES

To examine, by ultrasonography the prevalence of thyroid nodules in a cross sectional study of male medical workers occupationally exposed to chi radiation at the Pisa hospital, in comparison with controls matched for age and sex.

METHODS

50 male medical workers exposed to radiation were randomly matched for age (+/- 2 years) with 100 male workers not occupationally exposed to ionising radiation who lived in a slightly iodine deficient area of Tuscany (Lunigiana) (control group 1), and with 100 male workers not exposed to radiation who lived in the same area (Pisa) (control group 2).

RESULTS

Of the occupationally exposed subjects, thyroid nodules were detected in 19/50 (38.0%). Among controls, thyroid nodules were detected in 19/100 subjects of control group 1 and in 13/100 of control group 2. Comparison of exposed and control groups, stratified into 30-39, 40-49, and 50-59 year old age subgroups, showed a higher significant relative risk for thyroid nodules in the exposed subjects.

CONCLUSION

The results suggest that occupational exposure to radiation may be a risk factor for thyroid nodules.

Substernal goiter: a clinical review

Thyroid disease is a very common problem, but indications for surgery are few. We have seen a large number of patients with multinodular goiter. The main indications for surgery in thyroid disease include fear of malignancy, tracheo-esophageal compression, and cosmetic reasons. Tracheo-esophageal compression is most commonly noted in patients with mediastinal goiters. Substernal goiter is defined as those situations in which at least 50% of the gland is in the mediastinal location. Although its incidence has decreased, it remains prevalent in almost every country in the world today. SSG is best diagnosed by a thorough history and physical examination, complemented by airway films, fiberoptic laryngoscopy, and computerized tomography. The most common presenting symptoms are those produced secondary to compression effects. SSG show a poor response to medical treatment. Moreover, given their propensity to cause acute airway symptoms, surgical treatment should be considered in most cases. Extirpation of the gland is best performed through a collar incision, with the addition of a median sternotomy in select few and difficult cases. Median sternotomy is necessary in only 1% to 2% of cases. Operative mortality is negligible, and the incidence of complication is minimized by following strict surgical principles.