An autonomously functioning thyroid carcinoma associated with euthyroid Graves' disease.

A 39-yr-old man with an autonomously functioning thyroid carcinoma is presented. Only 17 similar cases have been reported in the literature. The patient had unilateral Graves' ophthalmopathy. He was euthyroid as reflected by normal TSH concentration, whereas the results of a T3 suppression test established the presence of autonomous thyroid function. A thyroid scan with (123)I revealed a hot nodule corresponding to the location of a papillary carcinoma and remained substantially unchanged after T3 administration. The hyperfunction of the carcinoma itself was clearly confirmed by the intense concentration of (131)I within the tumor on microautoradiograms. While a hot nodule on radioiodine scan is unlikely to be malignant, the possibility of carcinoma should not be overlooked.     

The role of thyroid scanning in hyperthyroidism

Radionuclide thyroid imaging was performed in 872 consecutive patients with hyperthyroidism. Of these, 84% were found to have diffuse toxic hyperplasia (Graves' disease), while 12% had autonomously functioning nodules (Plummer's disease), 3% had Graves' disease developing in a multinodular gland, and in the remaining 1%, either a clear diagnosis could not be established or the hyperthyroidism was due to thyroiditis or the Jod-Basedow phenomenon. It was found that a thyroid scan seldom provides additional diagnostic information in patients with Graves' disease when a diffuse goitre is present. However, if patients are to be treated with radioiodine (131I), thyroid imaging with tracer quantitation can replace a 24-h 131I uptake measurement, this having the advantages that the patients are required to attend only once, and that the gland size can be measured. In addition, visual confirmation of tracer uptake by the thyroid is obtained and patients with thyroiditis will not receive inappropriate therapy. When single or multiple thyroid nodules are palpated, a thyroid scan is crucial in establishing an accurate diagnosis, as it is not otherwise possible to differentiate between Plummer's disease and Graves' disease developing in a multinodular gland. Indeed, in 20 of our 63 patients (32%) with single autonomously functioning nodules, the initial clinical assessment had been incorrect.     

The role of thyroid scanning in hyperthyroidism

Radionuclide thyroid imaging was performed in 872 consecutive patients with hyperthyroidism. Of these, 84% were found to have diffuse toxic hyperplasia (Graves' disease), while 12% had autonomously functioning nodules (Plummer's disease), 3% had Graves' disease developing in a multinodular gland, and in the remaining 1%, either a clear diagnosis could not be established or the hyperthyroidism was due to thyroiditis or the Job-Basedow phenomenon. It was found that a thyroid scan seldom provides additional diagnostic information in patients with Graves' disease when a diffuse goitre is present. However, if patients are to be treated with radioiodine (¹³¹I), thyroid imaging with tracer quantitation can replace a 24-h ¹³¹I uptake measurement, this having the advantages that the patients are required to attend only once, and that the gland size can be measured. In addition, visual confirmation of tracer uptake by the thyroid is obtained and patients with thyroiditis will not receive inappropriate therapy. When single or multiple thyroid nodules are palpated, a thyroid scan is crucial in establishing an accurate diagnosis, as it is not otherwise possible to differentiate between Plummer's disease and Graves' disease developing in a multinodular gland. Indeed, in 20 of our 63 patients (32%) with single autonomously functioning nodules, the initial clinical assessment had been incorrect.     

Thyrotoxic graves’ disease with normal thyroidal technetium-99m pertechnetate uptake

We saw 24 thyrotoxic Graves' patients with normal thyroidal uptake of technetium-99m pertechnetate (99mTc) out of 201 untreated thyrotoxic Graves' patients seen over 4 years. The clinical and laboratory findings for these patients were studied and analysed. Thyroid uptake and scintigraphic examinations by means of 99mTc, TBII and TSab activity measurement clearly distinguished these patients from other thyrotoxic disorders (destruction-induced thyrotoxicosis and autonomously functioning thyroid lesions). Different from other disorders, these patients had not lower but normal thyroid uptake and also showed diffuse and discrete trapping into the enlarged glands. These patients had significantly smaller goiters, a lower serum thyroid hormone level, and lower TBII and TSab activity, when compared with other high 99mTc uptake groups with Graves' disease, and their condition could be easily controlled with small amounts of antithyroid drugs. Our study indicates that thyrotoxic Graves' disease with normal 99mTc uptake exists and 99mTc uptake study and TBII activity measurement is very useful for the diagnosis. The normal 99mTc uptake thyrotoxic Graves' patient might be early stage patients with general Graves' disease and their early discrimination from general Graves' patients is very advantageous for treatment and prognosis.     

Role of radionuclide imaging in hyperthyroid patients with no clinical suspicion of nodules.

The purpose of the study was to assess the role of radionuclide imaging of hyperthyroid patients with no suspicion of nodules. (99)Tc(m) radionuclide scans performed on all 190 patients referred over a 2-year period with symptoms and thyroid function tests compatible with thyrotoxicosis were retrospectively reviewed. 73% of patients were referred by a hospital clinician and 27% were referred direct from the general practitioner. Referral letters and, where applicable, the clinical notes were reviewed and patients with suspected thyroid nodules were excluded. The results of (99)Tc(m) thyroid scans of the 190 patients (age range 23-93 years, mean 48 years) were reviewed. 152 (80%) patients had Graves' disease, 10 (5.3%) had Graves' disease with nodules, 6 (3.2%) had Graves' disease with non-functioning nodules, 5 (2.6%) had viral thyroiditis, 5 (2.6%) had autonomously functioning nodules and 12 (6.3%) were normal studies. Therefore, 20% of patients had a diagnosis other than solely Graves' disease. These diagnoses are important with respect to clinical management. In conclusion, routine radionuclide imaging is worthwhile, as a significant proportion of patients with clinical "Graves' disease" in this study would have received incorrect treatment without the result of this scan.     

131I治疗先天性甲状腺单叶缺如合并Graves病甲巯咪唑治疗后复发一例

笔者报道了1例131I治疗先天性甲状腺单叶缺如合并Graves病甲巯咪唑治疗后复发的病例,从临床症状、血清学化验、甲状腺超声及颈胸部SPECT/CT融合显像等方面分析该病例特点,并通过文献复习加深了对先天性甲状腺单叶缺如合并Graves病的认识。甲状腺单叶缺如合并Graves病患者在规律口服抗甲状腺药物治疗后出现复发,应尽早选择131I治疗。131I治疗仍是先天性甲状腺单叶缺如伴Graves病甲巯咪唑治疗后复发患者较为理想的方法。     

Elevated 18F-FDG uptake in skeletal muscles and thymus: a clue for the diagnosis of Graves' disease

AIM: The aim of this study was to evaluate the appearance of Graves' disease in whole-body 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging. SUBJECTS: Twenty patients (three men, 17 women; mean age +/- SD, 37.2 +/- 12.1 years) with newly diagnosed Graves' disease without anti-thyroid drug treatment took part in the study. Secondly, a control group, 15 examinees (three men, 12 women; mean age +/- SD, 45.3 +/- 13 years) each with a history of Graves' disease and post-medical treatment were recruited. This group showed normal thyroid function. Finally, a normal group, 32 physical check-up examinees with non-specific medical histories and normal thyroid functions, were recruited. Whole-body FDG PET was performed on all subjects. The intensity of FDG uptake in the thyroid, thymus and muscles region was graded subjectively on a five-point scale. RESULTS: Among the 20 patients with Graves' disease, only six (30%) showed thyroid uptake of FDG, 15 (75%) showed thymus uptake of FDG, and up to 19 (95%) showed symmetrical increased uptake of FDG in skeletal muscles. In particular, the skeletal muscle uptake of FDG in the psoas and rectus abdominis muscles was 19/20 (95%) and 12/20 (60%), respectively. In the control group, three of the 15 examinees showed thyroid uptake of FDG. In the normal group, four of the 32 examinees had faintly visualized thyroid uptake of FDG. In thymus and skeletal muscles, there was no substantially increased FDG uptake in control and normal group examinees. CONCLUSIONS: In patients with Graves' disease, the thyroid uptake of FDG is not uniformly increased. Symmetrically increased uptake of FDG in the skeletal muscles and thymus is a clue for the diagnosis of Graves' disease. The uptake of FDG in skeletal muscles is more specific in the psoas and rectus abdominis muscles. An increment of muscle FDG uptake may be responsible for the high peripheral glucose utilization seen in Graves' disease.     

Plummer’s disease with spontaneous progression to hypothyroidism

A case of Plummer's disease that spontaneously progressed to hypothyroidism is presented. A 49-year-old female visited our hospital because of a 3 kg decrease in body weight during the previous month and a painless nodule in the right anterior area of her neck. A diagnosis of Plummer's disease was made based on the results of thyroid function tests, thyroid scintigrams, and an ultrasonogram, but the patient's disease followed an usual clinical course. About two months later, she gradually developed manifestations of permanent hypothyroidism, and anti-thyroid autoantibodies became positive. In spite of continuous administration of levothyroxine sodium, uptake of 99mTcO4- to the nodule was unchanged or rather increased according to the consecutive thyroid scintigraphies. These results suggested that this case represented an autonomously functioning nodule with underlying silent thyroiditis and Hashimoto's disease.     

Visualisation of a thyroglossal duct

After ablation of an autonomously functioning thyroid nodule resulting from an adenoma, a previously suppressed scintigraphic image of a thyroglossal duct was visualised.     

Visualisation of a thyroglossal duct

After ablation of an autonomously functioning thyroid nodule resulting from an adenoma, a previously suppressed scintigraphic image of a thyroglossal duct was visualised.     

Low failure rate of fixed administered activity of 400 MBq 131I with pre-treatment with carbimazole for thyrotoxicosis: the Gateshead Protocol

BACKGROUND: Thyrotoxicosis is associated with significant morbidity, therefore adequate control of the disease is paramount. The outcome of treatment of thyrotoxicosis using radioiodine shows variable failure rates depending, amongst other things, on the administered activity of radioiodine and the use of anti-thyroid drugs. Thus, management should follow an evidence based protocol, which has a low failure rate. METHOD: We prospectively analysed the outcome of treatment using our Gateshead protocol of a fixed administered activity of radioiodine therapy (400 MBq) given to 201 patients (including 140 with Graves' disease, 48 with toxic multinodular goitre (TMNG) and 13 with toxic nodule) followed up for a median period of 12 months (range, 6-77 months). Carbimazole was discontinued in patients rendered euthyroid 16 days prior to radioiodine. No routine anti-thyroid drugs or thyroxine were given following radioiodine unless hypothyroidism or thyrotoxicosis occurred. RESULTS: Following the Gateshead protocol led to a failure rate of 6.5% (eight females with Graves' disease, four females with TMNG and one female with toxic nodule), 29% euthyroidism and 64% hypothyroidism. The rates of hypothyroidism for women and for men were: in Graves' disease 77% and 79%, in TMNG 29% and 75%, in toxic nodule 42% and 0%, respectively. CONCLUSIONS: Our observations show that withholding an antithyroid drug in excess of just over 2 weeks prior to administering a fixed administered activity of radioiodine in patients with thyrotoxicosis leads to the lowest reported failure rate, irrespective of the underlying cause. One possible mechanism for this could be the avoidance of drug induced radio-resistance.     

Percutaneous ethanol injection therapy for autonomously functioning thyroid nodule

Four patients with solitary autonomously functioning thyroid nodule (AFTN; 2 toxic and 2 subclinically toxic) received ultrasonography (US)—guided percutaneous ethanol injection therapy (PEIT). The pretreatment scintigraphic appearance of the nodule was hot, and radioactivity in the extranodular tissue was completely suppressed throughout. Ninety-nine percent ethanol was slowly injected under US guidance. As a rule, the injection was performed in fractionated sessions and the treatment was repeated until the total amount of ethanol exceeded the baseline nodular volume. The therapy was successful. Complete remission of hyperthyroidism was observed among the patients with toxic nodule. The basal level of TSH and its response to TRH injection was normalized in the patients with subclinically toxic nodule. Posttreatment scintigrams revealed that the extranodular tissue recovered and radioactivity in the hot nodule had noticeably decreased. The rate of reduction in the nodular volume was more than 80% in all. There was no recurrence or development of hypothyroidism during a follow up of 10 to 23 months. The main side effect was mild and transient pain and/or a burning sensation at injection. No severe or permanent complications occurred. Although the number of our cases was small, the results suggest that PEIT is a useful program in treating AFTN.     

Visualization of suppressed thyroid tissue by technetium-99m-tertiary butyl isonitrile: an alternative to post-TSH stimulation scanning

The autonomously functioning thyroid nodule (AFTN) is a discrete, nodular structure which operates independently of pituitary control and without relation to the remaining thyroid tissue. Presently, for the visualization of a suppressed thyroid lobe, a patient has to undergo the thyrotropin (TSH) stimulation test, which has several disadvantages. In this study we have used tertiary butyl isonitrile (99mTc-TBI), well known as a myocardial imaging agent, for visualization of the suppressed lobe. Thirteen of fourteen patients studied demonstrated a contralateral lobe on a 99mTc-TBI scan which was not visualized with a 99mTc0(4) or 131I scan. Although it is not possible to demonstrate the autonomous nature of the hyperfunctioning thyroid nodule using 99mTc-TBI, we conclude that it is feasible to use this agent to visualize the lobe without the TSH test.     

The thyroid scan in Hashimoto's thyroiditis: the great mimic

We have reviewed our experience over the past 5 years of 32 thyroid scans in Hashimoto's thyroiditis. A wide variety of images were obtained, the most common finding being that of an enlarged gland with diffusely increased tracer uptake, a pattern identical to that found in Graves' disease (eight patients). Of the remainder, four scans were normal, four showed an enlarged gland with normal tracer uptake, five a multinodular gland with normal tracer uptake, five a multinodular gland with high tracer uptake, five a single non-functioning nodule and in one patient there was low tracer uptake by the gland. It is apparent that the thyroid scan in Hashimoto's thyroiditis can mimic a wide range of thyroid disorders. Thus, taken in isolation, the scan findings can be misleading and should be evaluated in conjunction with current biochemistry.     

The clinician and the thyroid

The goiter prevalence in iodine-deficient regions is up to 25%-54%. The most frequent disease in these endemic areas is non-toxic goiter, which is, however, oftentimes connected with autonomously functioning thyroid tissue leading to borderline or overt hyperthyroidism. Other thyroid diseases like cancer, thyroiditis and hypothyroidism play only a minor role in a thyroid clinic, while cases of Graves' disease may be observed more frequently. The most cost-effective tools to evaluate thyroid patients are the hand, ear and mouth of the thyroid clinician. The differential diagnosis of thyroid disorders may be evaluated by a battery of diagnostic tools like in-vitro tests and high performance imaging modalities. Once the diagnosis is established, the appropriate therapeutic procedures (drugs, radioiodine, surgery) have to be chosen. This review should be considered as a guideline for the diagnosis and treatment of thyroid diseases. In addition, special problems concerning elderly patients and pregnant women are discussed, including the differential diagnosis of thyroid diseases.     

Coexistence of a nonfunctioning thyroid nodule in Plummer's disease demonstrated by thallium-201 imaging

A patient with Plummer's disease in whom a coexisting nonfunctioning thyroid nodule was detected by TI-201 imaging is presented. I-123 imaging revealed a hot nodule corresponding to the functioning nodule and little uptake in the rest of the thyroid. In contrast, two areas of abnormalities were noted on a TI-201 image: one corresponded to the hot nodule in I-123 imaging and the other was visualized in the suppressed part of the thyroid in the same lobe. This case revealed that TI-201 imaging is clinically useful in detecting coexisting nodules in the suppressed part of the thyroid.     

Thyroid uptake of gallium in Graves' disease

A patient with hyperthyroid Graves' disease presented with ptosis, leading to a workup for myasthenia gravis. An enlarged thymus gland was noted on computed tomography. A scan with gallium-67 citrate showed prominent and diffuse thyroid gland activity as well as prominent lacrimal activity. This finding of thyroid uptake of gallium led to the correct diagnosis of Graves' disease. Such a finding has not been reported previously. The associated thymic, thyroid, and orbital findings in Graves' disease are discussed.     

Ectopic functioning thyroid tissue in the thyroglossal duct detected by radionuclide imaging

A 49-year-old man with a clinical diagnosis of Graves' disease was referred for a thyroid scan and radioactive ablation of the gland. Tc-99m pertechnetate scan revealed a diffuse toxic goiter and radiotracer concentration in the thyroglossal duct. He was given 10 mCi of I-131 orally as treatment of thyrotoxicosis. Repeat scanning of the anterior neck 2 days later revealed concentration of radioiodine in the diffusely enlarged gland and the thyroglossal duct as found on the Tc-99m pertechnetate scan, thus confirming the presence of functioning thyroid tissue in the thyroglossal duct.     

Guideline for in vivo- and in vitro procedures for thyroid diseases (version 2)

The version 2 of the guideline for diagnostic standards of thyroid disorders is an update of the guideline published in 1999 and describes standards of in vitro and in vivo procedures. The following statements are modified: In vitro procedures: When measurement of the TSH-receptor antibodies is indicated, the guideline recommends the use of a second generation assay (recombinant human TSH-receptor as antigen). The functional assay sensitivity for the measurement of thyroglobulin should reach a value < or =1 ng/ml. Molecular genetic tests (RET proto-oncogene) are indicated in patients with a newly diagnosed medullary thyroid cancer and in the relatives of patients with hereditary medullary thyroid cancer. In vivo procedures: The sonographic examination should use a probe with a frequency of at least 7.5 MHz. Indications for the thyroid scintigraphy: nodule size > or =1 cm in diameter, autonomous goitre/nodule with clinical or subclinical hyperthyroidism, necessity of a differentiation between Graves' disease and chronic lymphocytic thyroiditis, therapy control after a definitive treatment and - in individual cases - the follow-up of untreated autonomous nodules.     

Uptake of thallium-201 in enlarged thyroid glands: concise communication.

We have investigated the thyroid uptake of Tl-201 in 37 patients with various types of goiter, and in six with normal thyroids. Significant thallium uptake was found in all cases in which there was thyroid enlargement, including Graves' disease, toxic thyroid nodule, primary hypothyroidism, simple goiter, Hashimoto's disease, thyroid carcinoma, and thyroid adenoma. If goiter was absent, however, there was no demonstrable uptake--e.g., in secondary hypothyroidism, subacute thyroiditis, and the normal controls. Thallium uptake did not correlate with thyroid function tests such as BMR, T3-RU, T3, T4, TSH, antithyroid antibodies, or the 24-hr I-131 uptake. In 23 patients with diffuse goiter, on the other hand, maximum Tl-201 uptake correlated well with thyroid weight: r = 0.836 (p less than 0.001); y = 0.02 x + 0.06.