Impact of congenital calcitonin deficiency due to dysgenetic hypothyroidism on bone mineral density.

The objective of the present study was to determine the effect of chronic calcitonin deficiency on bone mass development. The results of 11 patients with thyroid dysgenesis (TD) were compared to those of 17 normal individuals (C) and of 9 patients with other forms of hypothyroidism (OH): 4 with hypothyroidism due to inborn errors of thyroid hormone synthesis and 5 with Hashimoto's thyroiditis. The subjects received an intravenous calcium stimulus and blood was collected for the determination of ionized calcium (Ca2+), calcitonin, and intact parathyroid hormone. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. After calcium administration the levels of Ca2+ in the two groups of hypothyroidism were significantly higher than in the normal control group (10 min after starting calcium infusion: C=1.29 +/- 0.08 vs TD=1.34 +/- 0.03 vs OH=1.34 +/- 0.02 mmol/l; P<0.05), and only the TD group showed no calcitonin response (5 min after starting calcium infusion: C = 27.9 5.8 vs TD = 6.6 0.3 vs OH = 43.0 13.4 ng/l). BMD values did not differ significantly between groups (L2-L4: C=1.116 +/- 0.02 vs TD=1.109 +/- 0.03 vs OH=1.050 +/- 0.04 g/cm2). These results indicate that early deficiency of calcitonin secretion has no detrimental effect on bone mass development. Furthermore, the increased calcitonin secretion observed in patients with inborn errors of thyroid hormone biosynthesis does not confer any advantage in terms of BMD.

Identification of the sentinel lymph node stained with blue dye in breast cancer patients.

PURPOSE: This study aimed to evaluate the reproducibility of sentinel lymphadenectomy in breast cancer patients (T1N0M0 and T2N0M0) and its possibility of predicting the total axillary behavior. METHODS: A total of 25 patients were evaluated, all presenting palpable mammary nodes between 1.5 and 5 cm (T1 and T2), with clinically negative axillary lymph nodes (N0). After an incisional biopsy of the tumor and histopathological confirmation of invasive breast carcinoma, a study of the sentinel lymph node took place with a peritumoral injection of 4 ml of blue dye at 2.5%. After waiting for 15 to 20 minutes, a search for the blue stained lymphatic vase in the axillary fat was carried out, which would lead to the sentinel lymph node, stained or not. At that point, a mastectomy (20 patients) or a quadrantectomy (5 patients) was performed, both with axillary lymphadenectomy at grades 1, 2 and 3. The sentinel lymph nodes and the material from the axillary dissection were sent separately for an anatomicopathological test in paraffin. RESULTS: The lymph nodes were identified in 19 patients, which represented a 76% detection rate. There was a concordance between the sentinel lymphadenectomy and the standard axillary dissection in 68.4% of the patients. The false-positive and the false-negative rates observed were 10% and 55.5%, respectively. A higher detection rate was found in tumors larger than 2 cm and situated in external quadrants. CONCLUSIONS: Sentinel lymphadenectomy identified the sentinel lymph node in the majority of the patients in this study, although the high rate of false-negatives observed prevented an accurate staging.

Impact of congenital calcitonin deficiency due to dysgenetic hypothyroidism on bone mineral density

The objective of the present study was to determine the effect of chronic calcitonin deficiency on bone mass development. The results of 11 patients with thyroid dysgenesis (TD) were compared to those of 17 normal individuals (C) and of 9 patients with other forms of hypothyroidism (OH): 4 with hypothyroidism due to inborn errors of thyroid hormone synthesis and 5 with Hashimoto's thyroiditis. The subjects received an intravenous calcium stimulus and blood was collected for the determination of ionized calcium (Ca2+), calcitonin, and intact parathyroid hormone. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. After calcium administration the levels of Ca2+ in the two groups of hypothyroidism were significantly higher than in the normal control group (10 min after starting calcium infusion: C = 1.29 ± 0.08 vs TD = 1.34 ± 0.03 vs OH = 1.34 ± 0.02 mmol/l; P < 0.05), and only the TD group showed no calcitonin response (5 min after starting calcium infusion: C = 27.9 ± 5.8 vs TD = 6.6 ± 0.3 vs OH = 43.0 ± 13.4 ng/l). BMD values did not differ significantly between groups (L2-L4: C = 1.116 ± 0.02 vs TD = 1.109 ± 0.03 vs OH = 1.050 ± 0.04 g/cm²). These results indicate that early deficiency of calcitonin secretion has no detrimental effect on bone mass development. Furthermore, the increased calcitonin secretion observed in patients with inborn errors of thyroid hormone biosynthesis does not confer any advantage in terms of BMD.