Hormonal and isotope measure in thyroid carcinoma

Impairment of the TSH signal transduction system in human thyroid carcinoma cells

In order to further evaluate the role of TSH in the proliferation and the differentiation of human thyroid carcinoma cells, we have analyzed the function of the TSH receptor in the established thyroid carcinoma cell lines NPA and WRO. The TSH signal transduction system in the carcinoma cells was also compared with that in normal thyroid cells. Although unresponsiveness to bovine and human TSH was demonstrated by measurement of cAMP production and [3H]thymidine incorporation after treatment of TSH, cAMP production was induced after stimulation of these cells by forskolin, cholera toxin, and isoproterenol. Specific binding to 125I-TSH was demonstrated in both NPA and WRO cells in addition to the existence of a TSH receptor mRNA and thyroglobulin mRNA species, although thyroid-specific gene expression in these cells was not regulated by TSH. These findings suggest that the unresponsiveness to TSH in these cells may be due to an abnormality of TSH receptor-G protein coupling rather than to a decreased level of TSH-receptor expression or a Gs protein abnormality.

Management of thyroid nodules. II: Scanning techniques, thyroid suppressive therapy, and fine needle aspiration

For the differentiation of benign from malignant thyroidal disease, ultrasound displays anatomic but not histologic features. Other visualization techniques can be used including isotope scanning (radioiodine, 99m technetium, 241 americium fluorescence, 131 cesium, 67 gallium, 75 selenomethionine, 201 thallium, 32 phosphorus, 99m Tc-bleomycin, 197 mercury, 133 xenon), thermography, x-ray techniques (plain films, computed tomographic scan, xeroradiography, chest x-ray barium swallow, lymphography, angiography), and thyroid hormone suppression. Needle biopsy can be done by core biopsy (Vim-Silverman and drill biopsy), large needle biopsy for histologic processing and fine needle aspiration for cytologic interpretation. The latter is the safest, most reliable, and most cost-effective technique currently available to differentiate between benign and malignant thyroidal disease and has great promise for the future.