Normal values for thyroid ultrasonography, goiter prevalence and urinary iodine concentration in schoolchildren of the Veneto Region, Italy.

Goiter prevalence in school-age children and median urinary iodine concentration (UIC) are the main indicators of iodine deficiency in a population. In areas of mild iodine deficiency, where goiters are small, ultrasound is preferable to physical examination to estimate goiter prevalence. The World Health Organization (WHO) has adopted thyroid volume ultrasonography results from a survey of European schoolchildren as an international reference, but these values have recently been questioned. The aims of the study were: a) to determine regional normal echographic reference values of thyroid volume in children aged between 11 and 14 yr in the Veneto Region, in North-East Italy; b) to determine goiter prevalence by physical and ultrasonographic examination; c) to determine UIC in this section of the population. A cross-sectional study was carried out on 1730 schoolchildren, aged between 11 and 14, living in towns in low-lying areas, in the valleys of the pre-Alps and in the mountains between 600 and 1200 m. Thyroid volume was evaluated by inspection and palpation using the WHO criteria. In 560 children thyroid volume was determined by ultrasound. UIC was measured in 1368 children. On physical examination a grade I goiter was found in 7.5% of children. No goiter grade II or grade III was found. The regional thyroid volume reference values by ultrasonography were similar, or slightly lower (5-20%), to the corresponding WHO reference values. Mean UIC was 148 +/- 110 microg/l, with no difference between lowlands and uplands; UIC values less than 100 microg/l were found in about 30-35% of the children. UIC was higher in children using iodized salt than in non-users. No correlation was found between thyroid volume by ultrasonography and UIC. Thyroid volume was found to be bigger in upland children than in those in low-lying areas, probably because of low iodine intake in people living in the mountains in previous generations. This data show that Veneto is not a iodine-deficient area, with no presence of endemic goiter. However, the great number of children with a UIC of less than 100 microg/l also suggests the use of iodized salt in the Veneto Region.

The epidemiology and etiology of differentiated thyroid carcinoma.

Differentiated thyroid carcinoma (DTC) is a rare tumor with a relatively good prognosis, but in about 10% of cases it may be the cause of death. Papillary carcinoma is more frequent (about 70-80% of cases) and less aggressive than follicular cancer: the papillary/follicular ratio is increased in areas of high iodine intake. In recent years many genes have been found to be mutated in DTC, the most important of these being ras, ret, trk, and met. The relationship between radiation exposure and DTC is well recognized, especially in children. Since the Chernobyl nuclear accident, a high incidence of DTC has been found in children exposed to fallout.

Serum thyroglobulin measurements in differentiated thyroid cancer.

In pathological states, the serum thyroglobulin (Tg) concentrations are generally high. Therefore, a serum assay of Tg levels is not useful for the differential diagnosis between benign or malignant disease in the preoperative period. Serum Tg measurements are a suitable marker in the follow-up of patients with differentiated thyroid carcinoma (DTC) during the postoperative period. After total thyroidectomy, serum Tg concentrations were found to be undetectable in subjects without evidence of residual thyroid tissue or metastases; however, detectable serum Tg levels in subjects on and off thyroid hormone suppressive therapy indicate the presence of residual or metastatic thyroid tissue. An increase in serum Tg levels during thyroid stimulating hormone (TSH) suppression indicates that further investigations are necessary.

Medullary thyroid carcinoma: clinical features and long-term follow-up of seventy-eight patients treated between 1969 and 1986.

This article describes the findings of a retrospective analysis of data obtained on 78 patients with medullary thyroid carcinoma (MTC), recorded between 1969 and 1986, and then followed at the Thyroid Center of Padua (Italy). The ages of the patients ranged between 15 and 89 years, with a median age of 45. The female to male (F:M) ratio was 2.9:1. All patients except 2 had total thyroidectomy. In 70 cases the tumor was of sporadic type; there were 3 familial non-multiple endocrine neoplasia (MEN) MTC; 3 MEN IIa; and 2 MEN IIb. The median duration of follow-up was 15.9 years (13 patients were followed up between 15 and 20 years, and 9 longer than 20). At diagnosis, the tumor was intrathyroid (stage I and II) in 31 patients, with local lymphnodes involved (stage III) in 41 patients, and with distant metastases (stage IV) in 6 patients. A total of 34 patients died (4 were at stage II at diagnosis, 26 at stage III, and 4 at stage IV); 4 of them died of unrelated causes, the others with tumor. The median survival rate of the deceased patients was 6 years (41% of these patients died within 3 years and 24% after more than 10 years); 76% of the deceased patients were older than 45 years at diagnosis. A total of 44 patients are still alive, 22 are alive free of disease (with follow-up between 10 and 24 years, median 14.2 years) and 22 are alive with disease (median follow-up 12.2 years). Only 30% of the patients of both these groups was older than 45 years at diagnosis. Survival is strongly related to tumor stage and to age at diagnosis, because only 8 of the 34 deceased patients were younger than 45 years (and 2 of them died of unrelated causes); moreover, patients who were treated at earlier stages of the disease had better prognosis. Survival rate at 10 and 20 years was 95% for patients with tumor limited to the thyroid, whereas it was 55% and 28.6%, respectively, for patients at stage III and IV. Bone metastases were correlated with worse prognosis than distant metastases only to soft tissues. The sex did not affect survival. None of the patients who had postoperative low serum calcitonin (CT) levels and no response to pentagastrin stimulation showed recurrences in the follow-up. In patients with postoperative elevated serum CT levels, recurrences of the tumor increased over time. However, 30% of these patients continued to show only elevated CT levels without evidence of the disease, even after 15 years.

[Goiter and iodine deficiency in Veneto: study on 6285 elementary and media school children]. / Gozzo e carenza iodica nel Veneto: studio su 6285 ragazzi delle scuole elementari e medie.

The aim of this paper was to determine goiter prevalence and urinary iodine excretion in the Veneto region. An extensive epidemiological survey was carried out in school-aged children visiting 6285 students and testing 1861 urinary samples. A goiter prevalence of 8.8% was found: 7.7% of grade 1A and 1.1% 1B; in the pre-mountainous area the prevalence was higher than 10% (11.7% in the Treviso and 12.7% in the Vicenza area). Urinary iodine excretion was less than 100 micrograms/Cr in about 45% of all examined children with a peak of 20% under 50 micrograms/Cr in the Vicenza district. According to the WHO criteria, the goiter prevalence in the Veneto can be considered under the limits of the epidemic standards. However the use of iodized salt seems advisable also in this area.

Epidemiological survey of goiter and iodine deficiency in Veneto region.

The aim of this paper was to determine goiter prevalence and urinary iodine excretion in the Veneto region. It is known since ancient times that goiter prevalence has affected mainly the mountainous areas in Italy. An extensive epidemiological survey was carried out in school-aged children, visiting 5,439 students and testing 1,883 urinary samples. A goiter prevalence of 8.8% was found in the Region; 7.7% of grade 1A and 1.1% of grade 1B respectively; in the pre-mountainous area the prevalence was higher than 10% (11.7% in the Treviso area and 12.7% in the Vicenza area). Urinary iodine excretion was less than 100 mcg/cr in about 45% of all examined children, with a peak of 20% under 50 mcg/cr in the Vicenza district. According to the WHO criteria, the goiter prevalence in the Veneto area can be considered under the limits of epidemic standards. Nevertheless we feel that in light of the urinary data a prophylaxis with iodine added salt should be recommended in any case.

[Treatment of hot thyroid nodule with percutaneous ethanol injection: indications, complications, and prognostic factors]. / La cura del nodulo caldo della tiroide con alcolizzazione percutanea: indicazioni, complicanze e fattori prognostici.

Percutaneous ethanol injection (PEI) has recently been proposed as an alternative therapy for toxic thyroid adenomas, instead of conventional treatments (pharmacological, surgical and radiometabolic therapies). The aim of this study was to investigate efficacy, complications and prognostic factors of PEI treatment in a group of 74 patients, 14 men and 60 women, treated from May, 1991, to December, 1994. Twenty-seven patients had nontoxic (pre-toxic) nodules (normal T3 and T4 and undetectable TSH serum levels) and 47 toxic nodules (high serum levels of thyroid hormones). A mean of 1.6 ml ethanol/cc of nodule volume was injected in 3-14 sessions (mean = 6). Ten subjects were treated twice, and 2 patients three times. Results were defined as: 1) complete cure: normalization of T3, T4 and TSH levels and appearance of extranodular thyroid tissue at scintigraphy; 2) partial cure: reduction in thyroid hormones within the normal range but still undetectable TSH levels and still suppressed extranodular thyroid tissue at scintigraphy; 3) failure. Complete cure was obtained in 96% of nontoxic (pretoxic) nodules and 65% of toxic ones. Moreover, partial cure was seen in 27.5% more toxic nodules and failure in 7.5%. The most significant complications were a case of transient dysphonia and two cases of common jugular vein thrombosis, both resolved spontaneously. The most important prognostic factor was the degree of hyperthyroidism (as FT4 and T3 serum levels), while nodule volume was rather useless to predict the final result. In conclusion, PEI can be an alternative, effective and low-cost treatment for autonomous thyroid nodules, without any severe complication and well tolerated by the patients.

Prognostic value of early postoperative calcitonin level in medullary thyroid carcinoma.

AIMS: Serum calcitonin (CT) assay is commonly used in the diagnosis and follow-up of medullary thyroid carcinoma (MTC). The aim of this study was to ascertain whether serum CT levels, measured in the first few days after surgery, could be used to evaluate the efficacy of treatment. METHODS: A group of 33 patients was studied. In all patients the follow-up was more than 20 months. RESULTS: Preoperatively basal CT serum levels were high in all patients. Twenty-four hours after surgery CT serum levels dropped to within the normal range in 8 patients and 72 hours after operation in 7 others. In this group 1 patient was at stage I, 11 at stage II and 3 at stage III. Basal and pentagastrin stimulated CT levels continued to be in the normal range in these 15 patients 6 and 12 months after surgery and at the subsequent year by follow-up visits. No clinical or radiological evidence of disease was found during the follow-up in this group. In the other 18 patients CT was reduced but still high 72 hours after surgery; 6 months later basal serum CT levels continued to be elevated or responsive to pentagastrin stimulation. In this group restaging showed tumor relapse in the thyroid bed in 2 patients, cervical lymphadenopathy in 11, and distant metastases (bone, liver) in 3. CONCLUSIONS: Immediate postoperative CT serum levels seem to be the most useful index to evaluate the efficacy of surgical treatment and the presence of residual neoplastic tissue.