Search

RET (REarranged during Transfection) proto-oncogene variants are essential for the development of familial and sporadic forms of medullary thyroid carcinoma (MTC). The most frequent variants are usually located in exons 10, 11, and 13 through 16 of the RET gene. We report two cases of apparently sporadic MTC associated with the variant in exon 2 of RET gene. Patient 1, a 62-year old man who had undergone adrenalectomy for a 5 cm pheochromocytoma, was screened for type 2 multiple endocrine neoplasia (MEN 2) which showed elevated basal and post-intravenous calcium gluconate calcitonin levels. A fine needle aspiration biopsy (FNAB) confirmed the suspicion of MTC. The patient underwent total thyroidectomy and lymphadenectomy, and the histology showed C-cell hyperplasia with medullary microcarcinoma. Patient 2, a 57 years old woman, underwent total thyroidectomy for toxic multinodular goiter. Pre-operative FNAB had shown benign features, while basal calcitonin levels were only borderline increased. Final histology revealed medullary multifocal microcarcinoma. Genetic testing for RET protoncogene on DNA extracted from peripheral blood was performed in both patients and a missense variant on exon 2 (c.166C>A, p.L56M) was identified. To our knowledge, these are the first time two cases of MTC associated to RET p.L56M variant. Interestingly, one patient had also a pheochromocytoma suggesting a possible pathogenetic role of this variant in the genesis of MEN2A. While the association of this variant with MTC or MEN2A has been never reported, it has been described in association with Hirschsprung's disease.

Ectopic thyroid tissue is an abnormality caused by aberrant thyroid gland embryogenesis during its passage from the floor of the primitive foregut to its final position. The most frequent place of ectopic thyroid tissue is the base of tongue, whereas lateral thyroid gland is a very rare finding. The present case describes a case of thyroid dysgenesis, caused by a submandibular ectopic thyroid gland. Thyroid scintigraphy was crucial for the diagnosis: in fact, the patient was asymptomatic, and the diagnosis was performed only on the basis of subclinical hypothyroidism.

Aim: To determine the effect of levothyroxine (L-T4) therapy on the recurrence rate of nodular disease in patients previously treated with lobectomy for benign nodular goiter., Methods: Two hundred and thirty-tree patients (38 males, 195 females; age 49.9+/-13.1 yr) with no post-surgical evidence of nodular disease in the remnant, were followed- up yearly with serum TSH and ultrasound (US). Nodular recurrence was defined as a lesion of at least 5 mm at US. Patients were divided in 2 groups based on whether or not they had been treated with L-T4 after surgery: Group 1 (45 patients) who did not receive any L-T4, and Group 2 (188 patients) treated with L-T4. Group 2 was further subdivided in Group 2a (123 patients) receiving L-T4 substitutive therapy (TSH>or=0.5 and

Objectives: To report a first case of 21-hydroxylase deficiency associated with a new genotype determined by V281+I172N/V281L mutations of the CYP21A2 gene., Design and Methods: Direct genetic sequencing of CYP21A2 gene was performed., Results: Both siblings had the same genotype, namely V281+I172N/V281L, while their parents resulted as V281L and V281+I172N carriers, respectively., Conclusions: V281+I172N/V281L genotype should be included in the panel of mutations associated with the non-classical forms of 21-hydroxylase deficiency.

Objective: The term 'giant prolactinoma' can be used for tumours larger than 4 cm in diameter and/or with massive extrasellar extension. Cabergoline (CAB), a long-lasting dopamine agonist (DA), safe and well tolerated, is effective in normalizing PRL levels and inducing tumour shrinkage in micro- and macroprolactinomas. The purpose of this prospective study was to evaluate the efficacy and safety of CAB also for giant prolactinomas., Patients and Methods: Ten men with giant prolactinomas with a median age of 44.8 years were treated with CAB. Before CAB, four patients had previously undergone transsphenoidal surgery without modifying the parasellar extension of the tumour or their visual defects. Pretreatment serum prolactin (PRL) levels ranged between 1230 and 22 916 micro g/l (mean +/- SEM: 5794 +/- 1996) and tumour volume was between 21.8 and 105.5 cm3 (mean +/- SEM: 50.7 +/- 8.8). CAB was administered at an initial low dose of 0.5 mg three times a week and, in five patients who did not achieve serum PRL normalization, the dose was progressively increased up to 10.5 mg/week. The duration of treatment was 13-68 months (mean 38.9). PRL levels and pituitary target organ hormones were assayed before, after 30 days and then every 3 months after the beginning of CAB treatment. Magnetic resonance imaging (MRI) was carried out before, after 1-3 months, after 6 months and then every 10-12 months to evaluate tumour shrinkage., Results: In every patient, a significant PRL decrease (P = 0.0086) of at least 96% of the pretreatment values occurred (from 5794 +/- 1996 to 77 +/- 38, mean +/- SEM); a persistent normalization of PRL levels was achieved in five out of 10 patients (50%) beginning from the first 3-6 months of CAB treatment (only one patient needed 12 months of therapy). A significant tumour shrinkage (P = 0.0003) was achieved after 12 months of therapy in nine out of 10 patients (90%), with a volume reduction greater than 95% in three, of 50% in four and 25% in two patients. Tumour volume decreased from 50.7 +/- 8.8 to 28.6 +/- 9.4 and then to 22.3 +/- 8.8 cm3 (mean +/- SEM) after 6 and 12 months of CAB treatment, respectively. An improvement of visual field defects (VFD) was obtained in six of the seven patients presenting visual impairment before CAB treatment. Among the eight patients presenting libido and potency (L-P) failure, five normalized their PRL levels. In two of these a complete restoration of libido and potency was observed. Three patients with secondary hypoadrenalism and a patient with secondary hypothyroidism were treated with substitutive therapy during all the study time. The drug was well tolerated by all patients and no one discontinued the therapy., Conclusions: These data suggest that, in giant, aggressive prolactinomas, CAB represents a first-line therapy effective in reducing PRL levels and determining tumour shrinkage.

Medullary thyroid carcinoma is the least frequent thyroid neoplasm; it originates in thyroid parafollicular cells (calcitonin secreting C cells). In 80% of cases it is sporadic, in the remaining 20% it is familial, associated or not to other endocrinopathies as pheochromocytoma and hyperparathyroidism (MEN 2A, MEN 2B, and isolated familial medullary thyroid carcinoma). Preclinical diagnosis in relatives of affected subjects (preferably at pediatric age) is essential for successful therapy and is performed with genetic and biochemical screening tests. The genetic screening is based on DNA analysis (RET proto-oncogene mutations) of the patient, and if positive of all first degree relatives, to separate sporadic (somatic mutations) from familial (germline mutations) forms. The biochemical screening is based on calcitonin determination and its increase after pentagastrin stimulation, (a peculiar characteristic of medullary thyroid carcinoma, the first biochemical disorder in a subject at risk) and is mainly used in genetically silent familial medullary thyroid carcinoma. The principal negative prognostic factors of medullar thyroid carcinoma and the debate concerning the use of calcitonin determination in the diagnosis of the "cold" thyroid nodule have been analyzed.

Main guide-lines of medical therapy of benign thyroid diseases are reviewed. The most common drug therapy of the various forms of hyperthyroidism is represented by thionamide drugs (methimazole and propylthiouracil). Therapeutic protocols are diversified according to the disease. In Graves'disease medical therapy may present the definitive treatment, leading to remission in little less than 50% of cases while in hyperfunctioning nodular thyroid diseases, medical therapy is merely in preparation for ablation therapy. Other drugs used in hyperthyroidism are also mentioned (inorganic iodine, potassium perchlorate, beta-blockers). Thyroxine replacement therapy in the various forms of hypothyroidism is then analyzed, discussing in particular the therapeutic protocols and follow-up of the various forms of hypothyroidism. Finally, the controversy about the indications and efficacy of TSH-suppressive thyroxine therapy is considered.