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The serum free triiodothyronine (FT3)/free thyroxine (FT4) ratio in patients with huge goitrous Hashimoto’s thyroiditis (HG-HT) is relatively high. We investigated the cause of high FT3/FT4 ratios. We measured the serum FT3, FT4, and thyrotropin (TSH) levels of seven patients with HG-HT who had undergone a total thyroidectomy. Eleven patients with papillary thyroid carcinoma served as controls. The activities and mRNA levels of type 1 and type 2 iodothyronine deiodinases (D1 and D2, respectively) were measured in the thyroid tissues of HG-HT and perinodular thyroid tissues of papillary thyroid carcinoma. The TSH levels in the HG-HT group were not significantly different from those of the controls. The FT4 levels in the HG-HT group were significantly lower than those of the controls, whereas the FT3 levels and FT3/FT4 ratios were significantly higher in the HG-HT group. The FT3/FT4 ratios in the HG-HT group who had undergone total thyroidectomy and received levothyroxine therapy decreased significantly to normal values. Both the D1 and D2 activities in the thyroid tissues of the HG-HT patients were significantly higher than those of the controls. However, the mRNA levels of both D1 and D2 in the HG-HT patients’ thyroid tissues were comparable to those of the controls. Interestingly, there were significant correlations between the HG-HT patients’ D1 and D2 activities, and their thyroid gland volume or their FT3/FT4 ratios. Our results indicate that increased thyroidal D1 and D2 activities may be responsible for the higher serum FT3/FT4 ratio in patients with HG-HT.

We encountered a 55-year-old female patient with Hashimoto's thyroiditis who showed persistent fever, and could not find any source of fever other than the large nontender goiter. Her fever continued with positive CRP for 6 months. Although we did not assume that the inflammation was related to Hashimoto's thyroiditis, total thyroidectomy was performed for cosmetic reasons; however, fever was resolved immediately after thyroidectomy. Pathological diagnosis was Hashimoto's chronic thyroiditis. Immunohistochemical staining showed that the follicular cells were positive for IL-1alpha, IL-1beta, and TNF-alpha. We believed that fever was induced by inflammatory cytokines produced in thyroid. The case indicated that Hashimoto's thyroiditis with nontender goiter could cause idiopathic fever.

Benign thyroid teratomas are rare in adolescents and adults. We report on three cases of benign thyroid teratomas that presented as painful tumors in the neck after puberty. The tumor adjacent to the thyroid in each case showed rapid enlargement with predominant cystic lesions within several months. Ultrasonography and computed tomography revealed few findings suggesting the origin of the tumor. Cytological examination and culture of the aspirate failed to show cells originating from the thyroid or infectious findings, but revealed a small population of columnar epithelial cells or squamous epithelial cells. Chemical analysis of the aspirate showed levels of pancreatic enzymes higher than those in serum. The accumulation of cystic fluid in each case was refractory to drainage treatment or percutaneous ethanol injection therapy. The patients subsequently underwent resection of the tumor, and microscopic examination revealed various types of tissue including pancreas, adipose, cartilage, muscle, and skin, and the cystic wall was lined by gastric, intestinal, respiratory, and stratified squamous epithelium. Surgical resection was curative, and subsequent histologic examination revealed mature benign teratomas of the thyroid. The main characteristic of our cases presented the painful tumors due to the enlarged cystic formation lined by a variety of different types of epithelium, which agreed with previous cases of benign thyroid teratomas in adolescents and adults.

A novel treatment approach to Graves’ disease (GD), embolization of the thyroid gland arteries, is evaluated with respect to its indications and adverse effects. We describe an exacerbation of thyroid associated ophthalmopathy (TAO) following thyroid artery embolization in a woman with GD and mild stable TAO (NOSPECS classification, class I grade a). A 45-year-old woman with GD and inactive TAO, in whom thyroid function was stable following blockade of hormone release combined with replacement therapy, underwent embolization of three thyroid arteries. Initially, there were neither adverse effects nor complications; however, the patient developed severe TAO (NOSPECS classification, class IV grade b) 3 months after the arterial embolization. Steroid pulse treatments followed by total thyroidectomy resulted in improvement of the eye signs and symptoms. The clinical course and the serial changes of the thyroglobulin and thyroglobulin-antibody titers suggested that the destruction of thyroid follicles, induced by the arterial embolization, triggered the exacerbation of her TAO. Our experience argues for the use of caution when arterial embolization is considered for GD patients with even the mildest TAO (NOSPECS classification, class I).

There have been few studies on acute changes of bone metabolism in humans by thyroid hormone. This study aimed to examine the effects of triiodothyronine on serum markers of bone and mineral metabolism during a 7-d course of daily 75 microg therapy in 14 normal volunteers by drawing blood on 1, 2, 3, 5, and 7 d of therapy. Serum calcium concentrations did not significantly change during the course of therapy, while serum phosphorus concentrations were significantly (p0.05) decreased from 3.21 +/- 0.43 mg/dL (mean +/- SD) to 2.85 +/- 0.46 mg/dL on the 7th d. Serum PTH concentrations were significantly decreased from 339 +/- 116 pg/mL to 316 +/- 29 pg/mL. Serum concentrations of alkali-phosphatase and bone-specific alkali-phosphatase were not significantly changed, but serum osteocalcin concentrations were significantly increased from 5.71 +/- 1.98 mg/dL to 6.73 +/- 2.24 mg/dL. Serum carboxy-terminal propeptide of type I collagen concentrations were significantly decreased from 137.8 +/- 33.7 microg/L to 119.2 +/- 33.6 microg/L. Serum pyridinoline cross-linked telopeptide domain of type I collagen concentrations, a bone resorption marker, were significantly increased from 3.40 +/- 0.77 to 3.87 +/- 1.05 microg/L, and such significant increase was obtained from the 3rd day. The results indicate that some of bone and mineral markers change rapidly in response to triiodothyronine-induced acute thyrotoxicosis, but the manner of change is not the same as that of chronic thyrotoxicosis.