[The differential diagnosis of nodular formations of the thyroid]

Differential-diagnostic potentialities are considered of physical, instrumental, morphological and laboratory methods of investigation in nodular formations in the thyroid gland. Of first importance in the differential diagnosis are clinical methods that permit making an accurate diagnosis in 78% of cases; combined use of these methods with small-needle puncture biopsy, ultrasonic investigation increase the probability for the diagnosis to be correct up to 92%. Intraoperative macroscopic and rapid histological diagnosis appeared to be even more effective (95 to 97%).

[Prevalence of endemic goiter in the health sector of Zitenga (Burkina Faso)]

The prevalence of iodine deficiency disorders (IDD) was studied in the health district of Zitenga village (Oubritenga province, Burkina Faso), as part of an assisted development program. The study was designed to assess the prevalence of IDD in a population of more than 2,000 people. A multistage cluster sample of 210 people was randomly selected. The women in the sample were aged 0 to 45 years and the men, 0 to 25 years. Clinical and laboratory results (circulating TSH concentration, T4 and iodine excretion in urine), and dietary intake were recorded. The prevalence of goiter (all grades) was 55.2%. The values recorded for iodine excretion in urine showed that there was moderate iodine deficiency in this area. Blood thyroxine levels were below the laboratory reference range for 63% of the subjects, whereas TSH levels were above the laboratory reference range for 69.3% of the subjects. There was no correlation between hormone status, iodine excretion and goiter. The entire population of this area was deficient in iodine; some individuals had clinical signs of iodine deficiency, such as goiter. Further studies are required to investigate the factors responsible for goiter in this area and iodine supplementation should be provided for the population.

Endemic goitre prevalence in Ifedapo Local Government Area of Oyo State, Nigeria

As part of efforts aimed at providing an adequate data base for the control of iodine deficiency disorders (IDD) in Nigeria, we undertook an extensive goitre survey of Ifedapo Local Government Area (LGA) of Oyo State, which lies within the goitre-belt of South-western Nigeria. Primary school pupils aged between six and twelve years were the subjects of the survey. From each of ten health districts of the LGA, one primary school was included in the survey. For each school, the entire school population was assessed for goitre by palpation and goitre graded according to WHO/ICCIDD criteria. The survey included 3599 pupils (1889 males and 1710 females). The total goitre rate (TGR) for the LGA was 23.4% while the visible goitre rate (VGR) was 6.4%. The highest goitre rate was recorded in District I (Sango, Saki) TGR = 39.5%; VGR = 17.3%), while the lowest rate was seen in District 4 (Wasengare) TGR = 5.2%; VGR = 0.7%). Females had higher goitre rates than males (TGR: 25.7% vs 21.3%; VGR: 7.5% vs 5.5%). Most of the goitres were Grades IA (36.7%) or IB (35.7%). Goitre grades 2 and 3 accounted for only 27.3% and 0.2%, respectively. These results show that there is a mild to moderate IDD problem in Ifedapo LGA. The implications of this finding, in view of the known deleterious consequences of IDD, are discussed and the need for correction highlighted.

[Iodine and thyroid hormone metabolism in pregnancy]

The influence of pregnancy on thyroid function as well as important interactions of pregnancy and thyroid disorders are of high clinical importance. During the last decade knowledge of these issues greatly influenced clinical aspects and basic science. Because of the increasing frequency of thyroid disorders during pregnancy, knowledge of these issues is important in order to diagnose, treat and manage all patients exposed to these problems.

Management options for solitary thyroid nodules in an endemic goitrous area

An analysis of management of 546 cases of solitary thyroid nodules in an endemic area is presented. None of the evaluating procedures could effectively isolate benign from malignant disease. Of 508 cases considered clinically to be benign, 42 harboured malignancy on histological examination whereas of the 38 cases suspected clinically to be malignant, 21 were histologically benign. 131I-Thyroid scanning also lacked sensitivity in identifying malignant nodules since the prevalence of malignancy in cases which were 'cold' (44/316) was not significantly different from that amongst the 'uniform' cases (15/142). Fine-needle aspiration cytology, although the most sensitive and specific evaluating modality, did not decrease the number of operations for solitary thyroid nodules nor did it increase the incidence of malignancy amongst the operated cases, because of its limitations in differentiating benign from malignant follicular neoplasms. The conditions under which surgery was advocated are described.

[Value of fine needle puncture cytology, thyroid gland ultrasound and thyroid gland scintigraphy in diagnosis of thyroid carcinomas]

Szintigraphy of the thyroid gland is still one of the most important preoperative diagnostic procedures. Ultrasound of the thyroid gland is a highly sensitive, but less specific method. Fine-needle aspiration as an additional diagnostic method has a higher specificity in the case of a positive result.

Disorders of thyroid gland in India

The profile of thyroid disorders encountered in pediatric and adolescent age groups in India is similar to that seen in most parts of the world except for the prevalence of iodine deficiency disorders in certain endemic regions of this country. Clinical presentation is most commonly for hypothyroidism and goiters and infrequently for hyperthyroidism. Of nearly 800 children referred for thyroid problems, 79% had hypothyroidism (goitrous as well as nongoitrous), 19% had euthyroid goiters and 2% had hyperthyroidism. Hypothyroidism was due to thyroid dysgenesis in 75% (aplasia/hypoplasia--50% and ectopic thyroid gland 25%), thyroiditis in nearly 5% and dyshormonogenes is in 20%. The incidence of congenital hypothyroidism in our experience of screening nearly 40,000 newborns is about 1 in 2,640, which is much higher than the worldwide average of 1 in 3,800. Diagnostic delay in hypothyroidism is common and is related to lack of awareness amongst primary healthy care practitioners and family physicians as well as the cost and availability of laboratory investigations. This delay, compounded with inadequate therapeutic surveillance is responsible for the poor outcome in affected children. High incidence of dyshormonogenesis, inherited as autosomal recessive trait also calls for genetic counselling and routine sibling examination. Our results of family studies on first degree relatives of children with thyroiditis revealed presence of antimicrosomal antibodies in 43% and thyroid disease in 26%. Many etiologic factors cause goiters which may be functionally euthyroid or hypothyroid with almost equal frequency in our series. In nearly 200 schools children surveyed for goiter prevalence, 8% in high socioeconomic groups and about 21% in the low income group, had goiters. Female predominance was marked. However, iodine deficiency was not the sole cause as revealed by dietary survey and urinary iodine estimations. Hyperthyroidism is infrequent, less severe and in our experience responded well to long-term administration of antithyroid drugs. A high index of clinical awareness and education of primary health workers will help a great deal in improving the ultimate outcome in children with thyroid disorders/hypothyroidism.

Seven deadly sins in confronting endemic iodine deficiency, and how to avoid them

Iodine deficiency is a problem for almost all countries of the world. Goiter is its most obvious consequence, but others do more damage, particularly effects on the developing brain. In 1990, most countries and international agencies pledged the virtual elimination of iodine deficiency by the year 2000. The technology for the assessment and implementation is sufficient to attain this goal, but translating its potential into success requires careful planning. This article reviews seven major errors that frequently occur in iodine supplementation programs and offers suggestions for their avoidance. They are 1) unreliable assessment of iodine deficiency: the best indicators are urinary iodine concentration, thyroid size (preferably by ultrasound), blood spot thyroglobulin levels, and neonatal TSH determinations; the best group for surveys is schoolchildren; 2) poor iodine supplementation plan: iodized salt is the preferred supplement; its effective application frequently requires extensive changes in salt production and marketing, and poor handling of these changes will endanger the iodization program; other measures include iodized oil, iodized water, and iodine drops; all are occasionally useful, but the long range solution should generally be iodized salt; 3) exclusion of relevant stake-holders: the program should include not only health authorities but other arms of the government as well (education, commerce, agriculture, and standards), the salt industry, health professionals, and the iodine-deficient community itself; 4) inadequate education: an understanding of the effects of iodine deficiency and the means for its correction is essential at all levels, from government to affected population; 5) insufficient monitoring: the best instruments are urinary iodine levels, iodized salt use, and thyroid size, measured in representative groups at regular intervals with public reporting of results; 6) inattention to cost: the expense of iodization must be recognized and apportioned fairly; and 7) nonsustainability: for permanent success, an iodization program must be fair to all relevant parties and accompanied by a regular system of appropriate monitoring. Only with careful avoidance of these seven "deadly sins" can the goal of sustainable elimination of iodine deficiency be achieved.

[Euthyroid goiter in puberty--a harmless illness?]

An investigation was carried out in to thyroid hormones (TSH, T3, T4) and lipid parameters (total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride) in 136 adolescents (94 femals, average age 13 years). An iodine deficiency (grade II-II) with respect to the daily urine excretion per 1,73 m2 BSA was found in 75%. With few exceptions the serum levels of TSH and T4 were in the normal range. In 36% of the patients we noticed compensatory elevated T3 levels. Correlations between thyroid hormones TSH, T4, renal iodine excretion and the volume of thyroid glands were not detectable, only T3 showed a dignificant positive correlation to the thyroid gland volume. The average values of lipids in patients were found to be higher than in normals. We consider the changed lipids as a sign of a disturbed efficacy of thyroid hormones. The regional insufficient iodine supply causes goiters and to a high degree the observed hyperchole-sterolemia, too. Our results underline the necessity of a common iodine salt prophylaxis as well as the treatment of "harmless" goiters in puberty.

Thyroid function in a goitre endemia

A study was conducted to determine the thyroid function in a goitre endemia. Sadam is small village in the south district of Sikkim. Severe iodine deficiency exist in this village (prevalence of goitre 73.5%, cretinism prevalence 4%; mean urinary iodine exeretion 4.13 ng/dl - SD 3.1). Total of 72 out pf 142 households were randomly selected. All the inmates of the households above 14 years of age were examined for goitre and blood samples were collected from them for estimation of concentration of thyroid stimulating hormones (triiodothyroine T-3, thyroixe T-4) and thyroid stimulating hormone (TSH). Total of 244 subjects were examined, (137 males and 107 females). Goitre was detected in 149 (61.1%) individuals. The mean T-3, T-4 and TSH concentrations in the non-goitrous groups were (SD in parenthesis) 110.13 ng/dl (26.19), 10.12 ug/dl (2.38) and 1.01 uu/ml (0.52). The corresponding values for the goitrous group were, 132.22 ng/dl (46.25), 9.06 ug/dl (2.04) and 1.33 uu/ml (1.19). The differences in the mean concentrations between the goitrous and non-goitrous groups were statistically significant. An inverse correlation between the goitre size and T-4 on the one hand, and TSH and T-4 on the other hand was noticed. The result of the study show that functional decompensation of the thyroid occur in the majority of goitrous subjects.

[The effectiveness of iodine prophylaxis of endemic goiter in Slovakia from the viewpoint of physical and ultrasonographic examinations of the thyroid gland]

Being aimed at the effectivity of iodine prophylaxis of endemic goitre the authors examined 2946 children and adolescents at the age of 6-18 years during the period from 1989 to 1995 in 6 regions of Slovakia. The thyroid glands were examined physically and ultrasonographically. The authors have found out that the occurrence rate of diffuse goitre is acceptable and it is not meeting the criteria of endemic goitre. No case of nodular goitre was revealed. Similarly to the relative frequency of diffuse goitre, neither the ultrasonographically measured volumes of thyroid glands differed among various areas. They are comparable with the volumes detected in countries with a sufficient iodine supply. The use of criteria for iodine deficiency evaluation recommended by WHO (goitre occurrence, thyroid gland volume, ioduria) leads the authors to consider the current prophylaxis of endemic goitre as being effective and successful. (Tab. 5, Ref. 20.).

[Etiopathogenesis and therapy of iodine deficiency goiter]

The main cause of endemic goiter is iodine deficiency. For the last four decades, it has been thought that the reason for goiter development is the increased action of thyreotropin (TSH) on thyroid cell proliferation. During the last years, however, it became evident that local growth factors may be more directly involved in goiter formation and, furthermore, iodinated derivatives of membrane lipids are modulators of this growth factor's actions. TSH modulates both, the growth factor and growth factor receptor expression as well as the iodine content of the thyroid gland. In addition, most of the effects of TSH on thyroid volume seems to be the induction of thyroid hypertrophy, but not hyperplasia which is related to the action of local growth factors. These new insights in the pathophysiology of goiter development are important for the regimen of endemic goiter therapy. The current concept of goiter treatment by a TSH suppressive therapy has been derived from the previous hypothesis that TSH alone is more effective in causal goiter treatment than the TSH suppressive therapy.

[Neck tumors: struma]

Goiters are most commonly caused by increased, usually nodular growth of thyroid tissue ('simple' goiter), stimulation of thyroid growth by autoantibodies (Grave's disease) or thyroiditis. Rarer causes of goiter are malignant thyroid tumors and hereditary disturbances of thyroid hormone synthesis goiter: due to iodine deficiency should be found no longer in Switzerland because of the adequate iodine supplementation in this country. Differentiating the various types of goiters is usually possible on the basis of clinical signs and a few laboratory tests (e.g. measurement of thyroid antibodies). 'Simple' goiter is usually treated surgically. Hyperthyroid Grave's goiter is primarily treated with thyrostatic drugs, if it recurs; radioiodine of surgery are also used. Subacute thyroiditis causing goiter is treated symptomatically with analgesics anti-inflammatory drugs, while patients with chronic thyroiditis are given thyroid hormones when hypothyroidism occurs. Malignant tumors of the thyroid are treated surgically; in some cases additional therapy with radioiodine is indicated.

Racial disparity in the prevalence of thyroid disorder during pregnancy

A study to determine the prevalence of goitre and abnormal thyroid status during pregnancy in Malaysian women was conducted. Two hundred and three women (Malay = 85, Chinese = 47 and Indian = 71) in the third trimester and with no known thyroid disease were studied. There was a marked racial disparity in the prevalence of goitre: Indian 61%, Malay 28% and Chinese 29% (p = 0.001). The serum thyrotropic hormone (TSH) was significantly higher in Indians (median: 1.36 uIU/ml) compared to Malays (1.14 uIU/ml, p = 0.009). The serum albumin was also significantly lower in Indians (mean +/- sd; 36.12 +/- 3.9 mmol/l) compared to Malays (39.3 +/- 4.8 mmol/l) or Chinese (39.1 +/- 5.2) (p < 0.001). Thyroid antibody was detected in 14.6% of these women with no significant racial difference in its prevalence. Three women were found to be thyrotoxic but none were hypothyroid. This study found a high prevalence of goitre among the pregnant Indian women, probably related to the protein malnutrition state. The high prevalence of positive thyroid antibody in our population indicates that a high percentage of women are at risk of developing postpartum thyroiditis.

[Rational diagnosis of thyroid gland diseases]

The recommendations for the diagnosis of diseases of the thyroid gland issued seven years ago by the Thyroid Gland Section of the German Society of Endocrinology continue to apply, and are still relevant. On this basis, the main procedures available for effective and rational diagnostic evaluation are discussed. Depending upon the case history and clinical findings, a diagnostic strategy is developed for the most common benign diseases of the thyroid gland.

Pendred's syndrome

Although 5% of all cases of congenital deafness are caused by Pendred's syndrome, there are few reports in the literature. Seven patients with Pendred's syndrome in three families living in the same village were detected. For that reason, the syndrome is reviewed in light of the literature. The sex distribution of the patients with Pendred's syndrome and their families was recorded. We tested for thyroxine, triiodothyronine, thyroid-stimulating hormone, triiodothyronine resin uptake, and perchlorate, and performed caloric testing. In one patient, subtotal thyroidectomy was performed. In the histopathologic study, a thyroid nodule filled with colloid was found. Chromosome studies showed no anomalies in any patient. Five of the patients were deaf-mutes. We observed that the parents were cousins in all three families. These families also had healthy children, and the existence of the syndrome in both sexes points to an autosomal recessive trait.

Goiter incidence and urinary iodine excretion in children of age group 6-13 years living in south-eastern Poland (Kraków coordinating center)

The study included 4103 school children attending randomly selected schools localized in towns and villages of 3 geographically distinct regions: mountainous, (Carpathian endemia), upland, lowland. The children were divided into four age-related groups. The incidence of goiter as detected by palpation was 38.1% in all the children studied, the value being similar in all three regions (38.1, 37.3 and 38.6%, respectively). Goiter incidence differs slightly among urban and rural children, amounting to 40.5 and 34.5%, respectively, in the two groups. In about 60% of children urinary iodine excretion was lower than 50 micrograms/l, while in about 30% it was normal. In about 10% of children studied urinary iodine excretion was lower than 20 micrograms/l. The results obtained indicate the occurrence among children of the studied region of goiter endemy of moderate degree. It was found that the percentage of children excreting more than 50 micrograms/l of urinary iodine was higher among those consuming iodized salt as compared to those consuming non-iodized salt. The first effects of resumption of common salt fortification with iodide in southern Poland can already be noted. There is, however, a need for optimization and steady control over this prophylactic action.

[Dietary iodine deficiency. Its consequences in the aged]

Persisting dietary iodine deficiency in the Federal Republic of Germany is reflected in endemic goiter, in particular in the elderly. Among 581 over-60-year-olds, 48.8% revealed enlargement of the thyroid gland on sonography. Thyroid nodules were present in 101 cases, and a cystic lesion in another 43. Goiter is appreciably less responsive to levothyroxine in the elderly than in younger patients. The indication for initiating such medication should therefore be established on an individual basis. A specific problem of iodine deficiency goiter in the elderly is the increasing development with age of autonomously functioning nodules in the thyroid. Iodine contamination can induce thyrotoxicosis, which is often difficult to treat; in the individual case, thyroidectomy must be performed.

[Goiter in school children from the Swietokrzyski region]

5982 of children living in Kielce district, aged 6.5-14.5 years were randomly selected for the study. The size of the thyroid gland was examined clinically. In some children the estimation of serum T3, T4 and TSH was performed, as well as iodine urine excretion. The iodine content in drinking water was also measure. The results of the study show that the Kielce district belongs to the mild degree of iodine deficiency. The verification of the iodine prophylaxis in this region is necessary.

[Comparison of thyrotropin (TSH), thyroxine (TT4) and triiodothyronine (TT3) concentration in capillary and venous blood serum in children and adolescents]

The thyrotropin, thyroxine and triiodothyronine concentration was compared in sera from capillary and venous blood (n = 50) using a luminescence-enhanced enzyme immuno assay. The results showed a good correlation (TSH, r = 0.991, TT4, r = 0.988, TT3, r = 0.975) and a linear relationship. It is concluded that serum of capillary blood can be used for the in vitro diagnosis of thyroid function.