Outcome after treatment of papillary thyroid microcarcinoma.

Patients with thyroid microcarcinoma (TMC) have favourable long-term prognoses. However, recurrences in the neck and distant metastases have been reported. The authors investigated independent factors associated with recurrence in an effort to define therapeutic guidelines. In this study they report the results of a retrospective review of patients followed at one Institution. 120 patients ( 96 females and 24 males; mean age 45.2 years) with a papillary thyroid microcarcinoma (PTC) < or =1 cm in greatest dimension were analyzed. All of them were followed for 5 to 15 years. 106 of them were managed aggressively (total thyroidectomy), the remainder treated with lobectomy alone. Radioiodine therapy was performed in 62/106 patients submitted to total thyroidectomy. Despite the different treatment and the presence of neck node metastases at the time of the diagnosis in 26 of the reported 120 patients (22%) and local invasion beyond the thyroid capsule in 20 (17%), only 1.7% of patients had neck nodal local recurrence. No patient died or developed distant metastases. In this preliminary study the authors conclude that the outcome of PMC is generally favourable, even in presence of lymph-node metastases and local invasion, independently of the primary treatment.

Low dose hexarelin and growth hormone (GH)-releasing hormone as a diagnostic tool for the diagnosis of GH deficiency in adults: comparison with insulin-induced hypoglycemia test.

GH deficiency (GHD) in adults must be shown by provocative testing of GH secretion. Insulin-induced hypoglycemia (ITT) is the test of choice, and severe GHD, treated with recombinant human GH replacement, is defined by a GH peak response to ITT of less than 3 microg/L. GHRH plus arginine (ARG) is a more provocative test and is as sensitive as ITT provided that appropriate cut-off limits are assumed. GH secretagogues are a family of peptidyl and nonpeptidyl GH-releasing molecules that strongly stimulate GH secretion and, even at low doses, truly synergize with GHRH. Our aim was to verify the diagnostic reliability of the hexarelin (HEX; 0.25 microg/kg, iv) and GHRH (1 microg/kg, iv) test for the diagnosis of adult GHD. To this goal, in the present study we 1) defined the normal ranges of the GH response to GHRH+HEX in a group of normal young adult volunteers (NS; n = 25; 18 men and 7 women; age, 28.5+/-0.6 yr) and in 11 of them verified its reproducibility in a second session, and 2) compared the GH response to GHRH+HEXwith that to ITT in a group of normal subjects (n = 33; 12 men and 21 women; age, 34.1+/-1.5 yr) and hypopituitaric adults with GHD (n = 19; 10 men and 9 women; age, 39.9+/-2.2 yr; GH peak <5 microg/L after ITT). The GH response to GHRH+ARG was also evaluated in all GHD and in 77 normal subjects (40 men and 37 women; age, 28.1+/-0.6 yr). The mean GH peak after GHRH+HEX in NS was 83.6+/-4.5 microg/L; the third and first percentile limits of the normal GH response were 55.5 and 51.2 microg/L, respectively). The GH response to GHRH+HEX in NS showed good intraindividual reproducibility. In GHD the mean GH peak after GHRH+HEX (2.6+/-0.7 microg/L) was similar to that after GHRH+ARG (3.6+/-1.0 microg/L), and both were higher (P < 0.001) than that after ITT (0.6+/-0.1 microg/L); the GH responses to GHRH+HEX were positively associated with those to ITT and GHRH+ARG. Analyzing individual GH responses, 100% had severe GHD after ITT (GH peak, <3 microg/L). After GHRH+HEX all GHD had GH peaks below the third percentile limit of normality appropriate for this test (i.e. 55.5 microg/L). Thirteen of 19 (68.4%) GHD subjects had GH peaks below 3 microg/L after GHRH+HEX but all 19 (100%) had GH peaks below the first percentile limit of normality (i.e. 51.2 microg/L). The GH responses to GHRH+HEX were highly concordant with those after GHRH+ARG. In conclusion, the present results define normal limits of the GH response to stimulation with low dose HEX+GHRH in normal adults and show that this test is as sensitive as ITT for the diagnosis of adult GHD provided that appropriate cut-off limits are considered.

The age of patients with thyrotoxicosis factitia in Italy from 1973 to 1996.

Thyrotoxicosis factitia, a syndrome due to the surreptitious ingestion of excess thyroid hormones, has generally been diagnosed in young or middle-aged women with psychopathological disturbances. We reviewed all the cases seen at our Institution over a 24-yr period, from 1973 to 1996. All 25 patients were women. Analysis was restricted to 17 patients who were born and lived in Tuscany (our region), since only these patients were distributed during the whole observation period. Diagnosis of thyrotoxicosis factitia was based on the following parameters: elevated serum total and/or free thyroid hormone levels, undetectable serum thyrotropin levels, low/undetectable serum thyroglobulin concentration, normal urinary iodine excretion, low/suppressed thyroidal radioactive iodine uptake (RAIU), absence of goiter, absence of circulating anti-thyroid antibodies. Surreptitious ingestion of thyroid hormone pill was eventually admitted by all patients. Age at diagnosis was >50 yr in 7/17 patients (41%): 6 of them were distributed in the period 1995-1996, and one in 1988. Patients older than 60 yr were 5/17 (29%), all in the last two years of the period under investigation. There was an increase in the age of patients with thyrotoxicosis factitia (p=0.02), which lost a statistical significance when the patients of the 1995-1996 period were excluded from analysis (p=0.88). This study provides evidence of an increased age of patients with thyrotoxicosis factitia in more recent years. From a practical standpoint, our study suggests that thyrotoxicosis factitia should be suspected and adequately looked for even in old patients with thyrotoxicosis of inexplicable origin, especially in the absence of goiter and thyroid autoimmune phenomena, and when common causes of low-RAIU hyperthyroidism, such as a load with iodine-containing drugs or subacute thyroiditis, have been excluded.

Comparison of radioiodine with radioiodine plus lithium in the treatment of Graves' hyperthyroidism.

Effectiveness of radioiodine for Graves' hyperthyroidism depends also on its intrathyroidal persistence. The latter is enhanced by lithium by blocking iodine release from the thyroid. One hundred ten patients with Graves' hyperthyroidism were randomly assigned to treatment with radioiodine or radioiodine plus lithium, stratified according to goiter size (< or =40 or >40 mL) and evaluated for changes in thyroid function and goiter size, at monthly intervals, for 12 months. Cure of hyperthyroidism occurred in 33 of 46 patients (72%) treated with radioiodine and in 45 of 54 patients (83%) treated with radioiodine plus lithium. The probability of curing hyperthyroidism was higher and its control prompter (P = 0.02) in the radioiodine-plus-lithium group. Patients with < or =40-mL goiters had similar persistence of hyperthyroidism (13%), but lithium-treated patients had hyperthyroidism controlled earlier (P = 0.04). Among patients with >40-mL goiters, hyperthyroidism was cured in 6 of 15 patients (40%) treated with radioiodine alone and in 12 of 16 patients (75%) treated with radioiodine plus lithium (P = 0.07), and cure occurred earlier in the latter (P = 0.05). Goiters shrank in both groups (P < 0.0001), more effectively and promptly (P < 0.0005) in the radioiodine-plus-lithium group. Serum free T4 and T3 levels increased shortly after therapy only in the radioiodine group (P < 0.01). Lithium carbonate enhances the effectiveness of radioiodine therapy, in terms of prompter control of hyperthyroidism, in patients with small or large goiters. In the latter group, lithium also increases the rate of permanent control of hyperthyroidism.

Measurement of serum free thyroid hormone concentrations: an essential tool for the diagnosis of thyroid dysfunction.

Free thyroid hormones (free thyroxine, FT4, and free triiodothyronine, FT3) represent a more useful index of thyroid status than total thyroid hormones, because the latter are influenced by variations of thyroid hormone-binding proteins, especially T4-binding globulin (TBG). Thus, increased serum total T4 (TT4) and, in many instances, T3 (TT3) concentrations are encountered in euthyroid subjects with TBG excess, familial dysalbuminemic hyperthyroxinemia and transthyretin-associated hyperthyroxinemia, while decreased serum TT4 and TT3 levels are associated with TBG deficiency: under these circumstances, measurement of serum FT4 and FT3 levels correctly establishes the diagnosis of euthyroidism. In cases of suspected hyperthyroidism, a diagnostic strategy can be suggested based on serum FT3 (and TSH) measurement, since FT4 may occasionally be elevated, also in euthyroid subjects, e.g., in patients under chronic amiodarone or L-T4 treatment. When hypothyroidism is suspected, the most reliable test appears to be FT4 (together with TSH), because FT3 may still be normal in patients with subclinical or mild thyroid failure. In any case, it is essential that reliable free thyroid hormone assays be used, which are devoid of methodological limitations responsible for artifactual results under particular circumstances, such as thyroid hormone-binding protein abnormalities, pregnancy and nonthyroidal illness.