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Preoperative follicular lesion characterisation represents an unsolved diagnostic problem in thyroid nodular disease. Although fine-needle aspiration biopsy is the most reliable preoperative diagnostic procedure, it shows inherent limitations in differentiating adenoma from follicular carcinoma and, sometimes, follicular variants of papillary carcinoma. Galectin-3 cytoplasmic neoexpression has been proposed as a peculiar feature of thyroid malignant cells, easily detectable in cytological and histological samples. The aim of this study was to re-evaluate the galectin-3 expression in a large sample of thyroid lesions using an immunohistocytochemical biotin-free detection system and a specific anti-human-galectin-3 monoclonal antibody in order to avoid the interference of technical factors, a cause of conflicting results recently reported by some authors. We analysed galectin-3 expression of 39 follicular carcinomas, 26 papillary carcinomas, and 105 adenomas in both cell-block samples and their histological counterparts. All cell-block and histological papillary carcinoma samples showed high levels of galectin-3 immunoreactivity. Thirty-four follicular carcinomas were positive, whereas 5 were negative in cell-blocks but positive in their histological counterparts. Twelve out of 105 adenomas expressed galectin-3 in cell-blocks and histological samples. The diagnostic accuracy of preoperative galectin-3 evaluation in adenomas vs follicular carcinomas was 90.0%. Galectin-3 expression was also investigated in 22 minimally-invasive follicular carcinomas. All of them showed galectin-3 immunoreactivity in both cytological and histo-logical specimens with the exception of two cases, where galectin-3 positivity was observed only in the surgical material. The routine correct use of galectin-3, by increasing the diagnostic accuracy of conventional cytology, improves the management of thyroid nodules and can lead to a sensitive reduction of useless thyroid surgeries.

We performed a combined stimulation test with the simultaneous application of GnRH (100 μg), TRH (200 μg) and ACTH (10 μg) in 10 healthy adult males at two opposite clock timing, i.e. at 09:00 and 21:00 h. Pituitary (gonadotropins, PRL, TSH) and adrenal (Cortisol, aldosterone, progesterone) hormones showed a common trend of enhanced responsiveness to the evening challenge. Differences reached statistical significance in the case of Cortisol, aldosterone, PRL and FSH. These findings suggest that the responsiveness of some pituitary and adrenocortical hormones to specific stimuli is physiologically different in humans as a function of the clock timing, being higher in the evening than in the morning. From the clinical standpoint, however, differences in the magnitude of responses were not enough to recommend provocative testing at a particular clock time, at least for routine diagnostic purposes.