The survival rate of patients with medullary thyroid carcinoma (MTC) is significantly better in patients diagnosed and treated when the tumor is limited to the thyroid. In a pioneer study carried out in 1991, we demonstrated that routine measurement of serum calcitonin (CT) in nodular thyroid disease allowed the preoperative diagnosis of unsuspected sporadic MTC with better accuracy than routine fine needle aspiration cytology (FNAC). This finding has been confirmed in subsequent studies. In the present study we report the results of CT screening in 10,864 patients with thyroid nodular disease seen in the years 1991-1998 (group 1). We analyzed the prevalence of MTC and compared their outcomes with those of a historical group of patients (group 2) diagnosed before the introduction of CT screening (1970-1990). The prevalence of MTC found by CT screening in group 1 was 0.40% (44 patients). A positive CT test had a higher diagnostic sensitivity and specificity compared with FNAC. CT screening allowed the diagnosis of MTC at an earlier stage compared with group 2 (P = 0.004). Normalization of serum CT levels (undetectable) after surgery was more frequently observed in group 1. At the end of follow-up, complete remission was observed in 59% of group 1 and in 2.7% of group 2 (P = 0.0001). Our study confirms that MTC is not an infrequent finding among patients with thyroid nodules (nearly 1 in 250 patients). In addition, screening thyroid nodules with serum CT measurement allows the diagnosis and treatment of MTC at an earlier stage, resulting in a better outcome compared with MTC not detected by serum CT measurement. One of the reasons for this finding is that increasing the preoperative diagnostic accuracy of MTC prompts the surgeon to perform a more radical and possibly curative treatment. On this basis, routine measurement of basal serum CT levels should be considered an integral part of the diagnostic evaluation of thyroid nodules.

Selenium, a trace element that is fundamental to human health, is incorporated into some proteins as selenocysteine (Sec), generating a family of selenoproteins. Sec incorporation is mediated by a multiprotein complex that includes Sec insertion sequence-binding protein 2 (SECISBP2; also known as SBP2). Here, we describe subjects with compound heterozygous defects in the SECISBP2 gene. These individuals have reduced synthesis of most of the 25 known human selenoproteins, resulting in a complex phenotype. Azoospermia, with failure of the latter stages of spermatogenesis, was associated with a lack of testis-enriched selenoproteins. An axial muscular dystrophy was also present, with features similar to myopathies caused by mutations in selenoprotein N (SEPN1). Cutaneous deficiencies of antioxidant selenoenzymes, increased cellular ROS, and susceptibility to ultraviolet radiation-induced oxidative damage may mediate the observed photosensitivity. Reduced levels of selenoproteins in peripheral blood cells were associated with impaired T lymphocyte proliferation, abnormal mononuclear cell cytokine secretion, and telomere shortening. Paradoxically, raised ROS in affected subjects was associated with enhanced systemic and cellular insulin sensitivity, similar to findings in mice lacking the antioxidant selenoenzyme glutathione peroxidase 1 (GPx1). Thus, mutation of SECISBP2 is associated with a multisystem disorder with defective biosynthesis of many selenoproteins, highlighting their role in diverse biological processes.

Recombinant human TSH (rhTSH)-stimulated thyroglobulin (Tg) measurement and (131)I whole body scan (WBS) have been validated as informative tests in the postsurgical follow-up of differentiated thyroid carcinoma. We report the diagnostic accuracy of Tg measurement and diagnostic WBS, alone or in combination, after rhTSH stimulation in a retrospective, consecutive series of patients undergoing follow-up for differentiated thyroid cancer. Routine procedures also include neck ultrasound in every patient and post-therapy WBS when indicated. We studied 340 consecutive patients with differentiated thyroid carcinoma, previously treated with near-total thyroidectomy and (131)I thyroid ablation, scheduled for routine diagnostic tests. At baseline on L-T(4)-suppressive therapy, 294 patients had undetectable (<1 ng/ml) serum Tg and negative anti-Tg autoantibodies (TgAb), 25 patients had undetectable serum Tg and positive TgAb, and 21 patients had detectable serum Tg and negative TgAb. These patients were tested for the presence of active disease by rhTSH stimulation. The results of our study showed that rhTSH-stimulated Tg alone had a diagnostic sensitivity of 85% for detecting active disease and a negative predictive value (NPV) of 98.2%. After adding the results of neck ultrasound, sensitivity increased to 96.3%, and the NPV to 99.5%. rhTSH-stimulated WBS had a sensitivity of only 21% and a NPV of 89%. The combination of rhTSH-stimulated Tg and WBS had a sensitivity of 92.7% and a NPV of 99%. We conclude that the rhTSH-stimulated Tg test combined with neck ultrasonography has the highest diagnostic accuracy in detecting persistent disease in the follow-up of differentiated thyroid carcinoma. A detectable level of serum Tg on L-T(4), its conversion from undetectable to detectable after rhTSH, and/or a suspicious finding at ultrasound will allow the identification of patients requiring therapeutic procedures without the need for diagnostic WBS.

Higher TSH values, even within normal ranges, have been associated with a greater risk of thyroid malignancy. The relationship between TSH and papillary thyroid cancer (PTC) has been analyzed in 10 178 patients submitted to fine needle aspiration of thyroid nodules with a cytology of PTC (nZ497) or benign thyroid nodular disease (BTND, nZ9681). In 942 patients, submitted to surgery (521 from BTND and 421 from PTC), the histological diagnosis confirmed an elevated specificity (99.6%) and sensitivity (98.1%) of cytology. TSH levels were significantly higher in PTC than in BTND both in the cytological and histological series and also in patients with a clinical diagnosis of multinodular goiter (MNG) and single/isolate nodule (S/I). A significant agedependent development of thyroid autonomy (TSH !0.4 mU/ml) was observed in patients with benign thyroid disease, but not in those with PTC, diagnosed both on cytology and histology. In patients with MNG, the frequency of thyroid autonomy was higher and the risk of PTC was lower compared to those with S/I. In all patients, the presence of thyroid auto-antibodies (TAb) was associated with a significant increase of TSH. However, both in TAb positive and TAb negative patients TSH levels were significantly higher in PTC than in BTND. Our data confirm a direct relationship between TSH levels and risk of PTC in patients with nodular thyroid diseases. Thyroid autonomy conceivably protects against the risk of PTC, while thyroid autoimmunity does not play a significant role.

Amiodarone-induced thyrotoxicosis (AIT) occurs in both abnormal (type I) and apparently normal (type II) thyroid glands due to iodine-induced excessive thyroid hormone synthesis in patients with nodular goiter or latent Graves' disease (type I) or to a thyroid-destructive process caused by amiodarone or iodine (type II). Twenty-four consecutive AIT patients, 12 type I and 12 type II, were evaluated prospectively. Sex, age, severity of thyrotoxicosis, and cumulative amiodarone dose were similar. Type II patients had higher serum interleukin-6 (IL-6; median, 440 vs. 173 fmol/L; P < 0.001), but lower serum thyroglobulin levels. Several weeks of thionamide therapy in eight type II or prolonged glucocorticoid administration in two type I patients had previously failed to control hyperthyroidism. Type II patients were given prednisone (initial dose, 40 mg/day) for 3 months and achieved normal free T3 and IL-6 after an average of 8 and 6 days, respectively. Exacerbation of thyrotoxicosis with increased serum IL-6 values, observed in 4 patients while tapering steroid, was promptly corrected by increasing it. Type I patients, given methimazole (30 mg/day) and potassium perchlorate (1 g/day), achieved normal free T3 and IL-6 concentrations after an average of 4 weeks. Exacerbation of thyrotoxicosis with markedly increased IL-6 was controlled by prednisone in 3 of 4 cases. Distinction of different forms of AIT is essential for its successful management. Type II AIT should be treated with glucocorticoids; type I AIT should be treated with methimazole and potassium perchlorate. Exacerbation of thyrotoxicosis, which may occur in both forms and is probably related to destructive processes, should be controlled by the addition/increase in glucocorticoids.

DTC patients diagnosed after 1990 have smaller tumors with less advanced stage and a better prognosis. The question of whether this is related to the finding of tumors with a low clinical penetrance or to the anticipation of diagnosis remains to be clarified. Despite these significant differences, both advanced stage and older age still represent the most important poor prognostic factors for survival.

Background: Germline RET gene mutations are causative of multiple endocrine neoplasia (MEN) 2 and may be identified by genetic screening. Three different syndromes are distinguished: MEN 2A, when medullary thyroid carcinoma (MTC) is associated with pheochromocytoma and/or parathyroid adenomas; MEN 2B, when accompanied by a marfanoid habitus and/or pheochromocytoma; and familial medullary thyroid carcinoma (FMTC), when only MTC is present.

Complete ablation of thyroid tissue with its antigenic components results in the disappearance of antibodies to all major thyroid antigens, thus supporting the concept that continued antibody production depends on the persistence of autoantigen in the body.