Clinical Features of Ectopic Thyroid Gland / 대한내분비학회지

BACKGROUND: Ectopic thyroid gland is relatively rare condition and a developmental anomaly characterized by an aggregated of thyroid tissue in the midline anywhere from the base of the tongue to the mediastinum. The role of ectopic thyroid in the pathogenesis of non-goitrous sporadic cretinism and primary hypothyroidism has been emphasized. 19 cases of ectopic thyroid for 12 years was presented with Tc-pertechnetate or radioactive iodine, which were diagnosed by scintigraphy. METHODS: We wish to report these 19 cases and 12 cases of brief review of literatures on the incidence, etiology and development, symptomatology, diagnosis and treatment of ectopic thyroid gland was done. RESULTS: The most frequent incidental age was between the age 1 year and 29 years. And the frequency of ectopic thyroid was about 7 times more common in female(27 cases) than in male(4 cases). The location of ectopic thyroid were found to be lingual in 18 cases, sublingual in 9 cases, prelaryngeal in 1 case, and combine with lingual and sublingual in 3 cases. In chief complaints, palpable mass was most common and there were foreign body sensation on throat, dysphagia, dysphonia, and hoarseness. In 15 cases of hypothyroidism, l2 cases were taken thyroid hormone replacement therapy, 1 case was removed ectopic thyroid gland. In 2 of 10 cases of euthyroidism, replacement of thyroid hormone were done and 2 cases were removed ectopic thyroid gland, in 6 cases of unknown thyroid function, 1 case was removed ectopic thyroid gland and 131I therapy was done in 1 case, and others were observed with following up thyroid function test. CONCLUSION: These results suggest that the long terms thyroid function test, thyroglossal duct eyst and malignant change in ectopic thyroid tissue when finding the ectopic thyroid in thyroid scintigraphy were recommended highly.

Comparison of Double Phase 99mTc-sestamibi Scintigraphy with Evaluation of Hyperparathyroidism / 대한내분비학회지

"BACKGROUND: Between 80 to 85% of patients with hyperparathyroidsm have a solitary adenoma of the parathyroid glands and another 15% have a parathyroid hyperplasia. Preoperative localization of the parathyoid glands is generally accepted as warranted in patients who have failed an initial attempt at parathyroidectomy, ectopic locations and inexperienced surgeons. Different imaging techniques have been used for detection of abnormal parathyroid glands such as high resolution ultrasonography, computerized tomography, arteriography, venous sampling or magnetic resonance imaging and 201Tl/99mTc subtraction scintigraphy. But these methods have had varying rates of success, with low specificity and low sensitivity. Among the several different techniques available for parathyroid radionuclide imaging, the most common is the use of a dualradioisotope procedure combining of Tl with Tc. However, there are some controversies regarding the optimal technical aspects of this procedure, including the relative amount of injected dose of radiotracers, failed detection for small sized and deeper cervical located parathyroids, and not easy procedures. Recently, double phase Tc-sestamibi scintigraphy would be useful to solve these technical limitations, more convenient and have higher sensitivities. The purpose of this study was to compare the diagnostic accuracy of 99mTc-sestamibi with 201Tl/ 99mTc subtraction scintigraphy in the localization of hyperparathyroidism. METHODS: 9 patients with hyperparathyroidism underwent preoperative evaluation with double phase 99mTc-sestamibi scintigraphy and 201Tl/99mTc subtraction scintigraphy for attempted localization of abnormal parathyroid glands and surgical explorations. Imaging results were compared to surgical findings. RESULTS: Of 9 patients, 7 had a solitary parathyroid adenoma, 1 had a carcinoma and 1 had parathyroid hyperplasia. The 201Tl/99mTc subtraction scintigraphy preoperatively localized 8 of 9 patients(sensitivity: S9%) and 99mTc-sestamibi scintigraphy correctly localized all lesions for a sensitivity of 100%. In one case, 201Tl/99mTc subtraction scan show only a hot uptake at left upper parathyroid area, but 99mTc-sestamibi scan was shown the three site of hot uptake at left upper, both inferior parathyroid area. CONCLUSION: In patients with hyperparathyoridism, 99mTc-sestamibi scintigraphy may be used as the single imaging technique as it show a very high sensitivity and specificity in the preoperative localization of pathological parathyroid glands.