Thyroid gland nodules

Thyroid autonomy appears as a solitary toxic nodule or toxic multinodular goitre. In toxic thyroid, the nodule s synthesis and secretion of thyroid hormones is autonomous from the thyroid-stimulating hormone (TSH), which is produced in the pituitary gland. Accordingly TSH is suppressed and the extranodular thyroid tissue is functionally downregulated. Thyroid autonomy occurs frequently in iodine-deficient countries, whereas it is much less common in iodine-sufficient areas. Constitu-tively activating mutations in the TSH receptor and in the Gs a protein are the major molecular aetiology of toxic thyroid nodules. 

A 2.%i fear-old female complains of increasing anxiety and restlessness. Physical examination reveals tachycardia and tremors. Palpation of the neck reveals a 3-cm nodule on her thyroid gland. While awaiting laboratory confirmation of the diagnosis, she is given a drug that diminishes her tachycardia and tremors. 

Neoplastic effects in the NTP (1986) bioassay included increased incidences of neoplastic nodules in the liver in the male and female rats and hepatocellular adenoma or carcinoma (combined) in the male mice. Slightly elevated incidences of thyroid gland follicular cell tumors were additionally observed in exposed male mice, although the increases were equivocal. No exposure-related neoplastic changes were found in the chronic study of the 77.4% decaBDE mixture (Kociba et al. 1975 Norris et al. 1975a), but the power of this study to detect carcinogenic effects is limited by the very low dose levels in comparison to those tested in the NTP bioassay. 

Thyroid scans with 1l]I are useful in determining the activity of thyroid nodules in the intact thyroid gland. A nonradioactive, cold nodule indicates a higher risk of thyroid carcinoma, but the scan alone is not recommended as a technique of selecting patients for surgery. After removal of a thyroid carcinoma, a scan of the neck may demonstrate areas of increased activity in the cervical lymph nodes and other organs, indicating metastatic disease. 

Q7 In addition to Graves disease, the overactivity of one or more nodules in the thyroid can cause toxic multinodular goitre. An acute inflammation of the thyroid gland can also lead to thyroiditis, which produces a transient thyrotoxicosis. 

Finally, irrespective of the treatment option selected, careful follow-up is needed for all patients treated for Graves disease. Long-term follow-up should include regular examination of the thyroid gland and measurement of circulating levels of thyroid hormones once or twice a year. All newly-appearing thyroid nodules should be biopsied or excised. 

Before ultrasound-guided fine-needle aspiration came into use, scintigraphy was believed to be the most important test for the evaluation of nodules in the thyroid gland. Scintigraphy should, however, still be used when the patient with a nodule has low serum thyroid-stimulating hormone (TSH) value, to confirm the diagnosis of a toxic adenoma. 

Surgical removal of parts of the thyroid gland ( hot nodules or tumour tissue)... 

In the thyroid gland, Blastomyces dermatitidis causes small irregular nodules. There is preponderance of macrophages and numerous multinucleated giant cells (Chick 1971, Fig. 30). 

Endocrine Black discoloration of the thyroid gland occurred in a 31-year-old woman who had taken minocycline for 18 months before presenting with hyperthyroidism and a palpable thyroid nodule a concurrent papillary microcarcinoma was probably coincidental [135 ]. 

Peritoneal sarcoidosis is rare and can present with ascites (240). The CA-125 serum level may be elevated and therefore, this entity may be confused with ovarian carcinoma (241). Very rarely sarcoidosis may involve the gastrointestinal tract (242). Any portion of the gastrointestinal tract may be involved (242), and care must be taken to distinguish it from the granulomatous inflammation from Crohn s disease (242,243). Rarely sarcoidosis can affect the thyroid gland, presenting as thyroiditis, a nodule, or mass (244,245). 

Autonomous secretion of thyroid hormones by toxic nodules or adenomas of the thyroid gland. 

Under optimal conditions, a cold nodule of 0.7 cm could be detected in a thyroid gland that was normal with respect to iodine content. When compared with other imaging instruments at a similar level of nodule-to-background activity (99mTc) the gamma camera resolution (pin-hole collimator) was superior, but the resolution of the rectilinear scanner was about equal to that obtained with the thyroid fluorescence unit. 

The severity of induced irradiation is related to the efficiency of the iodide trapping mechanism in the thyroid gland. Subsequent deleterious effects of thyroidal irradiation are the development of thyroid cancer, thyroid nodules and hypothyroidism (1-2). Radiobiological aspects of the problem have been reviewed by Dr. Malone. The present paper deals with the conditions which are responsable for the irradiation level of the thyroid gland by 1311 jn a given population. 

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