[Risk markers of follicular neoplasms in thyroid nodules]

Thyroid nodules of follicular origin include neoplastic and non neoplastic processes. No methods of diagnosis or cytological features (obtained by fine-needle aspiration, FNA) may differentiate both types, and therefore differential diagnosis still constitutes a dilemma.We analyzed the existing association between clinical variables and methods of diagnosis in thyroid nodules of follicular type with the aim of defining risk of neoplasm. Ninety two patients with nodular goiters, of follicular origin by cytology, previously submitted to surgical treatment were analyzed. The studied variables were: sex, age, size of the nodule, ultrasound characteristics, cytological diagnosis, TSH level and results of the scintigraphy. Of 92 cases, 74 were neoplastic nodules (56 adenomas and 18 differentiated thyroid cancer) and 18 were non neoplastic nodules. Markers, that were related to high risk of follicular neoplasm corresponded to the cytological diagnosis of proliferation of high follicular degree, in iso or hypoechoic, and hypofunctioning nodules with I131. The carcinomas presented cytology of follicular proliferation of high degree, in hipoechoic nodules, of irregular edges with microcalcifications and hypofunctioning, in male patients or patients younger than 20 years. The presence of macrocalcifications and hypercaptation would be in favor of nodules of benign origin.The correlation of diagnostic methods and clinical variables in thyroid nodules of follicular type would allow us to differentiate the risk of neoplasm or carcinoma, and plan surgical selective treatments.

[Non-incidental papillary microcarcinomas of the thyroid]

The clinical significance of papillary microcarcinoma of the thyroid gland keeps being controversial. Its high prevalence in autopsies and as incidental findings in thyroidectomy specimens for benign pathology indicate an indolent clinical behavior. Nevertheless some of the microcarcinomas develop lymph node metastasis and local recurrence. To determine the clinical and pathological characteristics of non-incidental papillary microcarcinomas of the thyroid (PTM -NI). 18 patients with diagnosis of non-incidental papillary microcarcinoma (tumor < or = 1 cm) with nodular expression in the thyroid gland or with lymph node metastasis have been studied. Initial diagnosis, prediction factors and evolution have been evaluated. Of 18 patients with PTM-NI, 12 demonstrated lymph node metastasis. 6 patients had positive fine needle aspiration (FNA) of palpable thyroid nodules. Multifocality and extraglandular extension were associated with lymph node metastasis. Seven of the nine metastatic lymph nodes diagnosed by FNA were cystic. Histologically 83.3% of the nodules in the thyroid were non-encapsulated and showed papillary growth pattern. Multifocality and extrathyroid infiltration were associated with lymph node metastasis at presentation. 46% of the patients with thyroid nodules > or = 4 mm and lymph node involvement (N1) showed recurrence/persistence. The non-incidental intrathyroideal papillary microcarcinoma without capsular involvement, extraglandular extension or lymph node metastasis (N0) did not demonstrate recurrence. These results suggest two groups of non- incidental papillary microcarcinoma of the thyroid (PMT-NI), one intraglandular without risk of evolution -N0- and other extraglandular at risk of recurrence -N1-.

Cytopathology of follicular tumours of the thyroid with clear cell change

A retrospective cytological study of nine follicular tumours of the thyroid with clear cell change was undertaken. In five clear cell adenomas and one moderately differentiated clear cell follicular carcinoma the epithelial cells occurred singly or in sheets and clusters; they sometimes assumed a trabecular or follicular pattern. The cells usually had pale diffusely vacuolated cytoplasm with ill-defined boundaries, a variable degree of anisonucleosis, nucleolar enlargement, and nuclear overlapping. Smears from a signet-ring cell adenoma contained in addition a few cells with large cytoplasmic vacuoles and compressed eccentric nuclei. In these cases a cytological diagnosis of 'follicular lesion' (or follicular neoplasia), clear cell type or signet-ring cell type, was given. A cytodiagnosis of 'carcinoma' was made only in the poorly differentiated follicular carcinoma-clear cell variant studied which showed unequivocal features of malignancy. Features suggestive of thyroid cyst, nodular goitre, Hashimoto's thyroiditis, and cell hyperactivity (marginal vacuoles, 'fire flare') were also found in the aspirated specimens of these cases of clear cell tumour of the thyroid.

[Endemic goiter in school children of Salta Province, Argentina]

The Province of Salta, located in the northwest of Argentina, showed severe endemic goiter-cretinism. The purpose of our work, therefore, was to evaluate the results of the iodized salt prophylaxis measure implemented since 1963. In 1980-1981 the prevalence of goiter was determined in 16,935 school children whose ages ranged from four to 15 years. The urinary iodine/creatinine index was also determined in a subsample of 401 children. Findings revealed that the goiter prevalence in the Province was 16.1%. In 10 Departments of the Province, those with greater socioeconomic development and denser population, the prevalences found were below 10%, limit established as endemic. In the remaining 13 Departments, especially in those less developed--where mountainous regions make their access difficult and hence, their populations consume non-iodized salt obtained from natural salt basins--values exceeded this limit. The average ioduria was 104.0 micrograms I/g Cr, with 4.5% presenting values below 25 micrograms. After 20 years of prophylaxis, endemic goiter has therefore been partially eradicated. It is suggested, however, that consumption of iodized salt and, even the supply of iodized oil in those areas where prevalence is high, be recommended.