Background Current post-operative thyroid replacement dosing is weight-based with adjustments made following TSH values. This method can lead to significant delays in achieving euthyroidism and often fails to accurately dose over and underweight patients. Our aim was to develop an accurate dosing method that utilizes patient BMI data. Study Design A retrospective review of a prospectively collected thyroid database was performed. We selected adult patients undergoing thyroidectomy with benign pathology who achieved euthyroidism on thyroid hormone supplementation. BMI and euthyroid dose were plotted and regression was used to fit curves to the data. Statistical analysis was performed using STATA 10.1 (StataCorp, College Station, TX). Results 122 patients met inclusion criteria. At initial follow-up, only 39 patients were euthyroid (32%). 53% of patients with a BMI>30 were overdosed, while 46 % of patients with BMI<25 were under-dosed. The line of best fit demonstrated an overall quadratic relationship between BMI and euthyroid dose. A linear relationship best described the data up to a BMI of 50. Beyond that, the line approached 1.1 mcg/kg. A regression equation was derived for calculating initial levothyroxine dose (mcg/kg/day = −0.018*BMI +2.13 {F statistic =52.7, root mean squared error of 0.24}). Conclusion The current standard of weight based thyroid replacement fails to appropriately dose underweight and overweight patients. BMI can be used to more accurately dose thyroid hormone using a simple formula.

Background Fine needle aspiration (FNA) is the standard to evaluate thyroid nodules for malignancy. The aim of this study was to determine the influence of patient age and gender on the rate of thyroid nodule malignancy by FNA. Methods A database of 3,981 consecutive patients who underwent thyroid FNA between 2002 and 2009 was reviewed. The percentages of benign, indeterminate, and malignant biopsies based on patient age and gender were determined. Statistical analysis was performed using SPSS. Results Our patient population included 2,766 women (mean age ± SD, 52 ± 15.2) and 964 men (mean age ± SD, 59 ± 13.8). Of the 3,722 (93.5%) patients with diagnostic FNAs, 196 (5.3%) had malignant FNA cytology. Malignant FNAs were twice as frequent in patients age ≤45 vs. those >45 (8.1% vs. 4.0%, p<0.001). Overall, men had more indeterminate (10.2% vs. 6.3%, p<0.001) and malignant (6.7% vs. 4.8%, p=0.034) FNAs than women. Malignant FNAs in men were greatest in patients over age 45 (6.0% vs. 3.2%, p=0.001). The incidence of malignant FNAs for women peaked in their 30s (10.4%) whereas the incidence of malignant FNAs for men peaked 10 years later in their 40s (12.1%). Both men and women had the lowest incidence of malignant FNAs in their 70s (2.3% and 1.9% respectively). Conclusion The typical 5% risk of thyroid nodule malignancy on FNA varies depending on patient age and gender. A patient’s age and gender should therefore be considered when counseling someone of their risk of thyroid cancer by FNA.

Background Twenty-five percent of Medullary Thyroid Cancer (MTC) cases are hereditary. The ideal age for prophylactic thyroidectomy is based upon the specific RET mutation involved. The aim of this study is to determine if such age-appropriate prophylactic thyroidectomy results in improved disease-free survival. Methods Twenty-eight patients underwent thyroidectomy for hereditary MTC at our institution. Age-appropriate thyroidectomy was defined according to the North American Neuroendocrine Tumor Society (NANETS) guidelines. Patients having age-appropriate surgery (Group 1, n=9) were compared to those having thyroidectomy past the recommended age (Group 2, n=19). Results The mean age was 13 ± 2 years and 61% were female. Patients in Group 1 were younger than Group 2 (4 ± 1 vs. 17 ± 2 years, p<0.01). There were no significant differences in gender or RET mutation types between these two groups. Group 1 patients were cured with no disease recurrence as compared to Group 2 patients who had a 42% recurrence rate (p=0.05). Sub-analysis of Group 2 identified that patients who underwent surgery without evidence of disease did so at a shorter period following the guidelines as compared to those who underwent therapeutic surgery (2 ± 2 vs. 16 ± 2 years, p=0.01) and had longer disease-free survival (100% vs. 27%, p=0.005). Conclusion Patients with hereditary MTC should undergo age-appropriate thyroidectomy based on RET mutational status to avoid recurrence. Patients who are past the recommended age should have surgery as early as possible in order to improve disease-free survival.

The state of development of advanced embryos of the direct-developing Ecuadorian caecilian Caecilia orientalis (Caeciliidae: Gymnophiona: Amphibia) was examined. Because it is established that development is correlated with reproductive modes in a number of features, we included comparison with taxa that represent the major reproductive modes and all of the modern normal tables and ossification sequences. The embryos of C. orientalis most closely resemble those of stage 47/48 Gegeneophis ramaswamii, an Indian caeciliid, and stage 47/48 Hypogeophis rostratus, a Seychellian caeciliid, both direct developers, in details of bone mineralization, chondrocranial degeneration, and vertebrogenesis. They are most like stage 45 H. rostratus in external features (gills, pigmentation, etc.). They are less similar to prehatchings of Ichthyophis kohtaoensis, an ichthyophiid with free-living larvae, and to fetuses of the viviparous caeciliid Dermophis mexicanus and the viviparous typhlonectid Typhlonectes compressicauda at comparable total lengths in both skeletal development and external features. The similarity of developmental features among the direct-developers suggests a correlation with mode of life history. A noteworthy feature is that C. orientalis has an armature of multiple rows of teeth on the lower jaw with tooth crowns that resemble the "fetal" teeth of viviparous taxa and that are covered with a layer of oral mucosal epithelium until full development and eruption, but the upper jaw bears a single row of widely spaced, elongate, slightly recurved teeth that resemble those of the adult.