Presurgical assessment of the tumor burden of familial medullary thyroid carcinoma by calcitonin testing.

BACKGROUND: Early diagnosis of familial medullary thyroid carcinoma (MTC) is currently done by genetic analysis. These techniques have replaced calcitonin stimulation testing, which was previously used for this purpose. Some studies suggest a relationship between MTC spread and calcitonin levels. The aim of this study was to assess whether the tumor burden of MTC associated with multiple endocrine neoplasia type 2A (MEN 2A) syndrome can be estimated from the plasma calcitonin values before surgery. STUDY DESIGN: We retrospectively studied the relationship of basal and peak calcitonin values before thyroidectomy with histopathologic findings in 53 patients with MEN 2A syndrome from 14 families. The MTC was classified according to TNM staging. Analysis of variance was used for statistical analysis complemented with equality contrasts for pairs of means by the least significant difference method with a Student's t-test and with the Bonferroni's adjustment. RESULTS: A positive association was found between tumor stage and basal and peak calcitonin levels. There were significant differences between the following: mean basal concentrations of patients with C cell hyperplasia (CCH) (34.3 pg/mL) and TNM stage II (1,097.4 pg/mL), p < 0.01; CCH and TNM stage III (2,940.8 pg/mL), p < 0.001; TNM stage I (165.3 pg/mL) and stage II (1,097.4 pg/mL), p < 0.01, and between TNM stages I and III, p < 0.001. Poststimulation mean concentrations were different between CCH (48.7 pg/mL) and TNM I (514.2 pg/mL), p < 0.001. CONCLUSIONS: Preoperative calcitonin testing may be useful for assessing tumor spread and should be considered when deciding the extent of surgery for MEN 2A MTC.

The value of various definitions of intrathoracic goiter for predicting intra-operative and postoperative complications.

BACKGROUND: Intrathoracic goiter (IG) is a pathologic and clinical entity defined by criteria that varies from one series to the next. The objective of this study was to determine the most useful definition of IG for predicting intra-operative and postoperative complications. METHODS: The study included 201 patients treated for multinodular goiter who met the following criteria: (1) they had no previous thyroid surgery; (2) they had undergone total thyroidectomy; and (3) they were diagnosed with IG according to 1 of the following definitions: (1) clinical; (2) Hsu's; (3) Kocher's; (4) Torre's; (5) Eschapase's; (6) Lahey's; (7) Lindskog's; (8) Crile's; (9) Katlic's; and (10) subcarinal. Three variables were evaluated: (1) intra-operative complications; (2) need for a sternotomy; and (3) postoperative complications. RESULTS: During orotracheal intubation, there were difficulties in 25 cases, all of which were detected using the 6 least restrictive definitions of IG (these range from the clinical definition to Lahey's definition. In 6 (3%) cases, it was necessary to carry out a sternotomy. The thoracic approach could be predicted using Katlic's definition. None of the definitions of IG was useful for predicting postoperative complications. CONCLUSION: Most definitions of IG can be ignored because they are not clinically relevant. The 6 least restrictive definitions overlap in their utility to predict intubation difficult during the anesthetic process; consequently, the clinical definition should be used because it is the simplest to calculate. Katlic's definition is the most useful for predicting a possible sternotomy for extirpating goiter.

Adiponectin, the controversial hormone.

OBJECTIVE: To discuss present knowledge about adiponectin hormone. DESIGN: Review of existing literature. SETTING AND RESULTS: Adiponectin is one of the most interesting cytokines associated with obesity, although its physiological role remains to be fully clarified. Adiponectin is a 247-amino acid protein that contains four differentiable domains. Contrary to most adipose-related cytokines, adiponectin levels are surprisingly lower in obese than in lean humans. Women have been found to have significantly higher adiponectin plasma concentrations than men. Further research is needed in order to identify new polymorphisms which contribute to explain the potential role of adiponectin in obesity and related pathologies. Considering the anti-inflammatory properties of adiponectin and the fact that it is negatively associated with adiposity, this cytokine could be one of the links between obesity and inflammation. The main mechanisms of action of adiponectin are directed to a protective role against atherogenic and insulin resistance processes. Research has revealed interesting new functions far beyond metabolism, such as immunity, cancer and bone formation. Contrary to all adipose-related proteins, adiponectin decreases with obesity. Most of the contradictory data surrounding adiponectin are related to plasma values and their relationship with body fat, gender differences and insulin resistance. There are important confounding results regarding the mechanisms of action and functions of adiponectin, especially in relation to insulin resistance and inflammation.

Two-dimensional predictive equation to classify visceral obesity in clinical practice.

OBJECTIVE: Visceral obesity assessment is not easy, and although computed tomography (CT) is an accurate tool, this technique is expensive and sometimes not suitable in clinical practice. We developed a new two-dimensional elliptical anthropometric equation to classify visceral obesity and evaluated the validity and the reliability of the new equation compared with CT. RESEARCH METHODS AND PROCEDURES: We collected anthropometric and CT data from overweight/obese subjects (n = 61, BMI = 32.4 +/- 3.7 kg/m2). A validation group of 32 subjects was also selected. An equation for the assessment of visceral obesity was developed using multiple regression analysis. Once validated, the equation was compared with previous models. Tests for accuracy included mean differences, analysis of diagnostic, R2, Snedecor's F-test, and Bland-Altman plot. RESULTS: Multiple regression analysis revealed that the sagittal and coronal diameters and the triceps skinfold were significant contributors to the model. The final equation was: visceral area (VA)/subcutaneous area (SA)predicted = 0.868 + 0.064 x sagittal diameter - 0.036 x coronal diameter - 0.022 x triceps skinfold. Patients with visceral-subcutaneous area ratio (VA/SA) > 0.42 were classified as having visceral obesity. The predictive equation was valid, showing a significant association with VA/SA assessed by CT (VA/SA(CT); r = 0.68; p < 0.0001). Paired Student's t test showed no significant differences with VA/SACT (p = 0.541). The reliability was high [F(24/60) = 2.12; p = 0.01]. DISCUSSION: The new two-dimensional and elliptical predictive equation is valid to assess visceral obesity and is more precise than previous models.

Results of surgery for toxic multinodular goiter.

PURPOSE: We analyzed the clinical and histological features of patients operated on for toxic multinodular goiter (TMG) to determine the clinical profile and evaluate the surgical results. METHODS: We reviewed 672 patients who underwent surgery for multinodular goiter (MG), 112 (17%) of whom had hyperthyroidism, and analyzed the epidemiological, clinical, and surgical variables. RESULTS: The patients with TMG tended to be older than those with nontoxic MG, with a greater evolution time of the goiter and a higher rate of positive antithyroid antibodies. In the multivariate analysis, the only feature characteristic of TMG, as opposed to nontoxic MG, was the evolution time. Morbidity was 34%, representative of the fact that that most of the patients were seen before the establishment of our endocrine surgical unit. The hyperthyroid symptoms resolved in all patients, but 4 of 17 patients who underwent partial surgical resection showed signs of relapse within a follow-up period of 98 +/- 71 months. CONCLUSIONS: TMG is characterized by a long evolution time and is most effectively treated by total thyroidectomy, which achieves complete remission from symptoms, without relapse, and is necessary if there is associated carcinoma. However, the incidence of complications may be high if this procedure is not carried out by surgeons with experience in endocrine surgery.