Thyroid diseases are common worldwide. In India too, there is a significant burden of thyroid diseases. According to a projection from various studies on thyroid disease, it has been estimated that about 42 million people in India suffer from thyroid diseases. This review will focus on the epidemiology of five common thyroid diseases in India: (1) hypothyroidism, (2) hyperthyroidism, (3) goiter and iodine deficiency disorders, (4) Hashimoto's thyroiditis, and (5) thyroid cancer. This review will also briefly cover the exciting work that is in progress to ascertain the normal reference range of thyroid hormones in India, especially in pregnancy and children.

Background: Thyroid disorders are common endocrine disorders encountered in the African continent. Environmental and nutritional factors are often implicated in the occurrence of some thyroid disorders that occur in this part of the world. This is a narrative review that seeks to document the pattern, prevalence, and management of thyroid disorders in the continent. Materials and Methods: The search engine used for this review were PubMed and Google scholar. All available articles on thyroid disorders from the sub-African continent, published until May 2011, were included. Results: Iodine deficiency disorders (IDD) which top the list of thyroid disorders and remain the commonest cause of thyroid disorders in the continent is often affected not only by the iodine status in the region but sometimes also by selenium deficiency and thiocyanate toxicity. The reported prevalence rates of endemic goiter range from 1% to 90% depending on the area of study with myxedematous cretinism still a prominent feature of IDD in only a few regions of the continent. The extent of autoimmune thyroid disorders remains unknown because of underdiagnosis and underreporting but the few available studies note a prevalence rate of 1.2% to 9.9% of which Graves diseases is the commonest of these groups of disorders. Rarer causes of thyroid dysfunction such as thyroid tuberculosis and amiodarone related causes are also documented in this review. The onset of new thyroid diseases following amiodarone usage was documented in 27.6% of persons treated for arrhythmia. Reports on thyroid malignancies (CA) in Africa abound and differentiated thyroid malignancies are noted to occur more commonly than the other forms of thyroid CA. The documented prevalence rates of thyroid CA in the African continent are as follows (papillary: 6.7-72.1%, follicular: 4.9-68%, anaplastic: 5-21.4%, and medullary: 2.6%-13.8%). For the differentiated thyroid CA, there is a changing trend toward the more frequent occurrence of papillary CA compared to follicular CA and this may be attributable to widespread iodization programs. Our review shows that diagnosis and evaluation of thyroid disorders are reliant in most regions of the continent on clinical acumen and suboptimal diagnostic facilities and expertise are what obtain in many practices. The frequently employed management options of thyroid disorders in the continent are pharmacological and surgical treatment modalities. Conclusion: Diagnosis and management of thyroid disorders in the African continent remain suboptimal. Thyroid registries may be helpful to determine the scope of the burden of thyroid disorders since this knowledge may help change policies on the approach to the management of these disorders.

This compendium brings together traditional as well as contemporary scoring and grading systems used for the screening and diagnosis of various thyroid diseases, dysfunctions, and complications. The article discusses scores used to help diagnose hypo-and hyperthyroidism, to grade and manage goiter and ophthalmopathy, and to assess the risk of thyroid malignancy.

A large number of hypothyroid patients, receiving adequate doses of thyroxine supplementation, continue to complain of dissatisfaction and varied symptoms. This review discuses the concept of tissue hypothyroidism and suggests methods of measuring it, while calling for improvements in the medical management of hypothyroidism.

Central hypothyroidism is defined as hypothyroidism due to insufficient stimulation by thyroid stimulating hormone (TSH) of an otherwise normal thyroid gland. It has an estimated prevalence of approximately 1 in 80,000 to 1 in 120,000. It can be secondary hypothyroidism (pituitary) or tertiary hypothyroidism (hypothalamus) in origin. In children, it is usually caused by craniopharyngiomas or previous cranial irradiation for brain tumors or hematological malignancies. In adults, it is usually due to pituitary macroadenomas, pituitary surgeries or post-irradiation. Fatigue and peripheral edema are the most specific clinical features. Diagnosis is established by the presence of normal to low-normal TSH on the background of low-normal thyroid hormones, confirmed by the thyrotropin releasing hormone stimulation test. Therapy includes use of levothyroxine titrated to improvement in symptomology and keeping free T4 in the upper limit of normal reference range.

Thyroid diseases have widespread systemic manifestations including their effect on bone metabolism. On one hand, the effects of thyrotoxicosis including subclinical disease have received wide attention from researchers over the last century as it an important cause of secondary osteoporosis. On the other hand, hypothyroidism has received lesser attention as its effect on bone mineral metabolism is minimal. Therefore, this review will primarily focus on thyrotoxicosis and its impact on bone mineral metabolism.

The thyroid is the major regulator of metabolism and affects all of the bodily functions. Thyroid dysfunction is the second most common glandular disorder of the endocrine system which may rear its head in any system in the body including the mouth. The oral cavity is adversely affected by either an excess or deficiency of these hormones. Before treating a patient who has thyroid disorder, the endocrinologist needs to be familiar with the oral manifestations of thyroid dysfunctions. The patient with a thyroid dysfunction, as well as the patient taking medications for it, requires proper risk management before considering dental treatment by the dentist. Thus, communication of dentist with endocrinologist must be bidirectional, to maintain patient's oral and thyroid health.

Transient thyroid function abnormalities in the new born which revert back to normal after varying periods of time are mostly identified in the neonatal screening tests for thyroid and are becoming more common because of the survival of many more premature infants. It can be due to factors primarily affecting the thyroid-like iodine deficiency or excess, maternal thyroid-stimulating hormone receptor (TSHR) antibodies, maternal use of antithyroid drugs, DUOX 2 (dual oxidase 2) mutations, and prematurity or those that affect the pituitary-like untreated maternal hyperthyroidism, prematurity, and drugs. Most of these require only observation, whereas some, such as those due to maternal TSHR antibodies may last for upto three-to-six months and may necessitate treatment. Isolated hyperthyrotropinemia (normal Tetraiodothyronine (T4) and high Thyroid Stimulating hormone (TSH)) may persist as subclinical hypothyroidism in childhood. Transient hypothyroxinemia (low T4 and normal TSH) is very common in premature babies. The recognition of these conditions will obviate the risks associated with unnecessary thyroxine supplementation in childhood and parental concerns of a life long illness in their offspring.

Thyroidolody, the study of the thyroid gland, is considered to be a relatively new field of endocrinology. However, references to the thyroid gland and its diseases can be seen in the literature of ancient Greek, Indian and Egyptian medicine. Goiter has always been a disease of immense interest of the general population due to its widespread prevalence. It is one of the most common medical problems portrayed in ancient paintings. Owing to the lack of awareness and poor nutritious habits of the people in that era, diseases such as iodine deficiency goiter were common. Physicians, healers and philosophers had been attempting time and again until the 19 ^th century to come up with explanations of the thyroid gland and provide a reasonable basis of its diseases. Although the discovery of thyroid gland, its structure, function and diseases has been accredited to modern scientists who presented their work mostly in the 19 ^th and 20 ^th century, it is of significance to note that much of what we discovered in the 19 ^th and 20 ^th century had already been known centuries ago. This review attempts to explain the knowledge of thyroid gland, its function and diseases as held by the people in the previous centuries; and how this knowledge evolved over the years to become what it is today.

Aims: To study the prevalence of upper airway obstruction (UAO) in "apparently asymptomatic" patients with euthyroid multinodular goitre (MNG) and find correlation between clinical features, UAO on pulmonary function test (PFT) and tracheal narrowing on computerised tomography (CT). Materials and Methods: Consecutive patients with apparently asymptomatic euthyroid MNG attending thyroid clinic in a tertiary centre underwent clinical examination to elicit features of UAO, PFT, and CT of neck and chest. Statistical Analysis Used: Statistical analysis was done with SPSS version 11.5 using paired t-test, Chi square test, and Fisher's exact test. P value of <0.05 was considered to be significant. Results: Fifty-six patients (52 females and four males) were studied. The prevalence of UAO (PFT) and significant tracheal narrowing (CT) was 14.3%. and 9.3%, respectively. Clinical features failed to predict UAO or significant tracheal narrowing. Tracheal narrowing (CT) did not correlate with UAO (PFT). Volume of goitre significantly correlated with degree of tracheal narrowing. Conclusions: Clinical features do not predict UAO on PFT or tracheal narrowing on CT in apparently asymptomatic patients with euthyroid MNG.

Background: Fine-needle aspiration (FNA) is a useful method for evaluating multinodular goiter; however, its role is still controversial. The aim of this study was to assess the utility of ultrasound-guided thyroid FNA in detecting malignancy in patients with multinodular goiter in Oman. Materials and Methods: This was a retrospective study where all patients with multinodular goiter seen at the Sultan Qaboos University Hospital endocrinology clinic in Oman in 2005 were evaluated. The thyroid FNA results were grouped into either malignancy (positive result) or others (negative result). They were compared to those of final histopathological examination in order to calculate the value of the test in diagnosing malignancy. Analyses were evaluated using descriptive statistics. Results: A total of 272 patients were included in the study. The mean age was 39΁13 years with an age range from 5 to 85 years. The majority of the patients were females (n=236; 87%). The results of thyroid FNA revealed that 6% (n=15) of the patients had malignancies while histopathological results showed that the proportion of subjects with malignancies was 18% (n=49). Out of the 15 cases identified to have malignances by thyroid FNA, only 53% (n=8) of the subjects were confirmed to have malignancy by biopsy. Overall, the results of the tests were poor, revealing a sensitivity of 16%, specificity of 97% and a diagnostic accuracy of 82%, with a positive predictive value of 53% and a negative predictive value of 84%. Conclusion: Thyroid FNA is not a useful test in differentiating multinodular goiter from malignancy, as more than 80% of the malignancies go unnoticed.

The skin metastasis of papillary thyroid carcinoma (PTC) is a rare condition and the lesions should be differentiated from primary skin tumors. The scalp is the most frequent site which is involved in skin metastasis of PTC. It shows the poor outcome and aggressive nature of disease. In this report, we aim to present a case report of a 64 year-old female with scalp metastasis of PTC in the context of disseminated pulmonary and liver metastasis.

Dyshormonogenesis is an uncommon cause of congenital hypothyroidism. The most common abnormality is absent or insufficient thyroid peroxidase enzyme. Maternal intake of antithyroid drug can also lead to elevated thyroid stimulating hormone (TSH) in a neonate, albeit the scenario is temporary. We report one such interesting case where a clinically euthyroid neonate borne to a mother on antithyroid drug presents on 12 ^th day of life with reports of elevated TSH and increased tracer uptake in 99mTc thyroid scan. Disproportionately high TSH in comparison to low maternal antithyroid drug dosage and further elevation of TSH after stopping mother's antithyroid drugs ruled out maternal antithyroid drug-induced congenital hypothyroidism in the baby. Early institution of therapy in these patients can prevent mental retardation and other features of hypothyroidism.

Van Wyk-Grumbach syndrome (VWGS) is characterized by juvenile hypothyroidism, delayed bone age, and isosexual precocious puberty. A 10.7-year-old girl presented with premature menarche and isosexual precocity. She had delayed bone age and multicystic ovaries. High circulating levels of TSH with prepubertal LH confirmed the diagnosis of VWGS. Tendency to manifest sexual precocity in VWGS may be directly related to the severity of the TSH elevation. High circulating levels of TSH acting directly on FSH receptors are the actual mediators of precocity.

Pericardial effusion is frequently found in patients with hypothyroidism, but it is rarely associated with cardiac tamponade. Hypothyroidism complicated by cardiac tamponade is rarely referenced in the medical literature. Here we report an unusual case of a 45-year-old female, who presented with breathlessness and was found to have hypothyroidism with large pericardial effusion with cardiac tamponade. Treatment included an emergency pericardiocentesis followed by thyroxine hormone replacement.

This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recovery after the medical intervention and was discharged after 24 hours with no residual paralysis. Thyrotoxic periodic paralysis (TPP) is a complication of thyrotoxicosis, more common amongst males in Asia. It presents as acute flaccid paralysis in a case of hyperthyroidism with associated hypokalemia. The features of thyrotoxicosis may be subtle or absent. Thus, in cases of recurrent or acute flaccid muscle paralysis, it is important to consider thyrotoxicosis as one of the possible causes, and take measures accordingly.