Thyroid cancer in toxic and non-toxic multinodular goiter

Reappraising the role of thyroid scintigraphy in the era of TIRADS: A clinically-oriented viewpoint

Thyroid nodules (TNs) are a common entity, with the majority being benign. Therefore, employing an accurate rule-out strategy in clinical practice is essential. In the thyroid field, the current era is significantly marked by the worldwide diffusion of ultrasound (US)-based malignancy risk stratification systems of TN, usually reported as Thyroid Imaging Reporting And Data System (TIRADS). With the advent of US (and later TIRADS), the role of thyroid scintigraphy (TS) in clinical practice has gradually diminished. The authors of the present paper believe that the role of TS should be reappraised, also considering its essential role in detecting autonomously functioning thyroid nodules and its limited contribution to detecting thyroid cancers. Thus, this document aims to furnish endocrinologists, radiologists, surgeons, and nuclear medicine physicians with practical information to appropriately use TS.

Incidence and Risk Factors of Thyroid Malignancy in Patients with Toxic Nodular Goiter

Background. Although hyperfunctioning thyroid disorders were thought to be protective against malignancy, some recent studies reported a high incidence of incidentally discovered cancer in patients with hyperfunctioning benign thyroid disorders. We performed this study to estimate the incidence and predictors of malignant thyroid disease in patients with toxic nodular goiter (TNG). Patients and Methods. The data of 98 patients diagnosed with TNG were reviewed (including toxic multinodular goiter SMNG and single toxic nodule STN). The collected data included patients age, gender, systemic comorbidities, family history of thyroid malignancy, previous neck radiation, type of disease (multinodular or single), size of the dominant nodule by the US, operative time, and detection of significant lymph nodes during operation. Based on the histopathological analysis, the cases were allocated into benign and malignant groups. Results. Malignancy was detected in 21 patients (21.43%). Although age distribution was comparable between the two groups, males showed a significant increase in association with malignancy. Medical comorbidities and family history of cancer did not differ between the two groups. However, TMNG showed a statistically higher prevalence in the malignant group. Operative data, including operative time and lymph node detection, were comparable between the two groups. On regression analysis, both male gender and TMNG were significant predictors of malignancy. Conclusion. The presence of thyroid hyperfunction is not a protective factor against malignancy, as malignancy was detected in about 1/5 of cases. Male gender and TMNG were significant risk factors of malignancy in such patients.

Toxic adenoma: to biopsy or not to biopsy?

Toxic adenoma nodules rarely harbour cancer. Fine-needle aspiration (FNA) is often not done because of the rarity of these lesions being cancer, the difficulty in interpreting cytology in hyperthyroid patients and the rare precipitation of thyrotoxicosis. We present two young, Caucasian female patients aged 29 and 13 years who were each diagnosed with a toxic nodule categorised as benign and indeterminate respectively. They underwent hemithyroidectomy after being rendered euthyroid, however their histology unexpectedly revealed differentiated follicular cancer. Despite thyroid cancer being rare in patients with toxic adenomas, it should be considered when planning treatment, especially if there are risk factors for cancer, or suspicious features on ultrasound examination. A review of the literature shows that compared with adenomas in euthyroid patients, patients in this group are generally younger and predominately female. If an FNA is considered, it should be performed after the patient is rendered euthyroid.

Clinical characteristics associated with the finding of thyroid cancer originating from hot nodules in patients with hyperthyroidism: a case report and systematic review of the literature

Coexistence between thyroid cancer and hyperthyroidism is rare, and most of the nodular lesions from which a malignant tumor is documented in this group of patients correspond to cold nodules. Justified by the increasing number of reports in the literature about malignant tumors diagnosed from hot nodules, a systematic review was carried out to determine possible factors associated with the diagnosis of thyroid cancer from hot nodules in patients with hyperthyroidism. The results suggest that the clinical diagnosis of toxic nodular goiter, nodular lesions of diameter > 10 mm and a histological type compatible with a follicular carcinoma, are factors that on their own increase the risk of making the diagnosis of cancer from a hot nodule.

Current approach to surgical management of hyperthyroidism

Hyperthyroidism is a set of disorders that involve excess synthesis and secretion of thyroid hormones by the thyroid gland, which leads to thyrotoxicosis. The most common forms of hyperthyroidism include diffuse toxic goiter (Graves' disease), toxic multinodular goiter (Plummer disease), and a solitary toxic adenoma. The most reliable screening measure of thyroid function is the thyroid-stimulating hormone (TSH) level. Options for treatment of hyperthyroidism include: antithyroid drugs, radioactive iodine therapy (the preferred treatment of hyperthyroidism among US thyroid specialists), or thyroidectomy. Massive thyroid enlargement with compressive symptoms, a suspicious nodule, Graves' orbitopathy, and patient preference are indications for surgical treatment of thyrotoxicosis. This paper reviews the current literature and controversies on the surgical approach to the management of hyperthyroidism.

Prevalence and risk factors for thyroid cancer in patients with multinodular goitre

BACKGROUND

Rates of thyroid cancer in patients with multinodular goitre (MNG) vary widely, from 3 per cent in older studies to 35 per cent in more recent studies. The purpose of the present study was to evaluate the prevalence of thyroid cancer in patients operated on for MNG, and to determine risk factors for incidental thyroid malignancy.

METHODS

A prospectively developed database of all patients who underwent thyroidectomy for a benign MNG at the high-volume endocrine surgery unit of a tertiary referral university hospital was interrogated.

RESULTS

A total of 3233 patients were analysed, separated into three groups according to their functional thyroid status (hypothyroid, hyperthyroid or euthyroid). There were 2788 women (86.2 per cent); the mean patient age was 56.4 years and mean preoperative disease duration was 106.2 months. Incidental thyroid cancer was identified in 1026 patients (31.7 per cent), of which 917 (89.4 per cent) were papillary cancers. Multivariable regression analysis identified functional thyroid status, younger age, male sex, smaller adenoma size, smaller thyroid glands, Hashimoto's thyroiditis and chronic non-specific thyroiditis as independent risk factors for thyroid cancer.

CONCLUSION

MNG was associated with a considerable rate of incidental thyroid cancer, which has been underestimated. A variety of factors should be taken into account when considering the malignant potential of a presumed benign MNG.

Evaluation of ultrasonographical and cytological features of thyroid nodules in patients treated with radioactive iodine for hyperthyroidism

BACKGROUND

In this study, we aimed to evaluate ultrasonographical and cytological features of thyroid nodules in patients who were treated with radioactive iodine (RAI) for hyperthyroidism years ago.

METHODS

Patients who had a history of RAI treatment for hyperthyroidism and had thyroid nodules that were evaluated with fine-needle aspiration biopsy (FNAB) were included in the study.

RESULTS

There were 27 patients (22 female and 5 male) with a mean age of 59.3 ± 13.5. The indication for RAI treatment was Graves in 5 (18.6%), toxic nodular or multinodular goiter in 16 (69.2%), and unknown in 6 (22.2%) patients. A total of 48 thyroid nodules were evaluated with FNAB and cytological diagnosis were benign in 24 (50.0%), nondiagnostic in 15 (31.2%), atypia of undetermined significance in 5 (10.4%), suspicous for malignancy in 2 (4.2%), and malignant in 2 (4.2%) nodules. Thyroidectomy was performed in 10 patients, 5 were benign (50.0%), and 5 (50.0%) were malignant histopathologically. Ultrasonography features of 31 cytologically/histopathologically benign and five cytologically/histopathologically malignant nodules were compared. Prevalence of isoechoic nodules was higher in benign nodules (P = .025). Macrocalcification was observed in 4 (80.0%) of malignant and 10 (32.3%) of benign nodules (P = .042).

CONCLUSION

In patients with a history of RAI treatment for hyperthyroidism, thyroid nodules with suspicious ultrasonography features, particulary hypoechoic appearence and macrocalcification, should be evaluated with FNAB irrespective of the time elapsed after RAI treatment.

Should the Prevalence of Incidental Thyroid Cancer Determine the Extent of Surgery in Multinodular Goiter?

Background

The most appropriate surgical procedure for multinodular goiter (MNG) remains under debate. Incidental thyroid carcinoma (ITC) is often identified on histopathological examination after thyroidectomy performed for presumed benign MNG.

Aim of the study

The aim of the study was to determine the value of radical surgery for MNG patients considering the prevalence of ITC diagnosed postoperatively.

Materials and Methods

We conducted retrospective analysis of the medical records of 2,306 patients surgically treated for MNG between 2008 and 2013 at one center. None of the patients presented with any suspicion of malignancy, history of familial thyroid cancer, multiple endocrine neoplasia syndrome or previous head or neck radiation exposure.

Results

Among the 2,306 MNG patients, ITC was detected in 49 (2.12%) (44 women and 5 men, with average ages of 52.2 (21–79) and 55.6 (52–62), respectively). Papillary thyroid carcinoma was significantly more frequently observed than other types of ITC (p<0.00001). Among the MNG patients, 866 (37.5%) underwent total/near total surgery, 464 (20.1%) received subtotal thyroidectomy, and 701 (30.3%) received the Dunhill operation. The remaining 275 (11.9%) patients underwent a less radical procedure and were classified as "others." Among the 49 (100%) patients with ITC, 28 (57.1%) underwent radical surgery. Another 21 (42.9%) patients required completion surgery due to an insufficient primary surgical procedure. A total of 21 (2.42%) patients in the total/near total surgery group were diagnosed with ITC, as well as 16 (2.48%) in the subtotal thyroidectomy group and 12 (1.71%) in the Dunhill operation group; 21 (100%), 4 (25%) and 3 (25%) of these patients, respectively, underwent radical surgery; thus, 0 (0%), 12 (75%) and 9 (75%) required completion surgery. The prevalence rates of ITC were comparable between the radical and subtotal surgery groups (2.42% and 3.44%, respectively, p = 0.4046), and the prevalence was higher in the radical surgery group than in the Dunhill operation group (2.42% and 1.71%, respectively, p = 0.0873). A significant difference was observed between the group of patients who underwent total/near total surgery, among whom all of the patients with ITC (100%) received primary radical surgery, and the groups of patients who received the subtotal and Dunhill operations, among whom only 25% of the patients with ITC in each group received primary radical surgery (p<0.0001).

Conclusions

More radical procedures for MNG result in a lower risk of reoperation for ITC. The prevalence of ITC on postoperative histopathological examination should determine the extent of surgery in MNG patients. In the future, total/near total thyroidectomy should be considered for MNG patients due to the increased prevalence of ITC to avoid the necessity for reoperation.

Features and Outcome of Autonomous Thyroid Nodules in Children: 31 Consecutive Patients Seen at a Single Center

CONTEXT

Most thyroid nodules are benign and their accurate identification can avoid unnecessary procedures. In adult patients, documentation of nodule autonomy is accepted as reassurance of benign histology and as justification to forgo biopsy or thyroidectomy. In contrast, the negative predictive value of nodule autonomy in children is uncertain. Some recent publications recommend surgical resection as initial management, but few address the degree of TSH suppression or the specific scintigraphic criteria used to diagnose autonomy.

OBJECTIVE

The objective of the study was to study the presenting features and cancer risk of children with autonomous nodules.

DESIGN AND SETTING

Medical records of all 31 children diagnosed with autonomous nodules at our center from 2003 to 2014 were retrospectively reviewed.

PATIENTS AND RESULTS

All children met full diagnostic criteria for autonomous nodules, defined by both autonomous ¹²³I uptake into the nodule and the suppression of uptake in the normal thyroid parenchyma on scintigraphy performed during hypothyrotropinemia. The median age of presentation was 15 years (range 3-18 y) with a female to male ratio of 15:1. Fifty-eight percent of patients had solitary nodules and 42% had multiple nodules. The median size of each patient's largest autonomous nodule was 39 mm (range 18-67 mm). Most of the children in this series (68%) had diagnostic biopsies and/or operative pathology of their largest autonomous nodule, which showed benign cytology or histology in all cases.

CONCLUSIONS

In this pediatric series, the cancer rate observed in biopsied or resected autonomous nodules was 0%. Whereas larger studies are needed to confirm our findings, these results agree with earlier reports suggesting that thyroid cancer is rare in rigorously defined autonomous nodules and support that conservative management may be offered to selected children who meet strict diagnostic criteria for autonomous nodules, deferring definitive therapies until adulthood when the risks of thyroidectomy and ¹³¹I ablation are lower.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Can Ultrasound Predict Malignancy in Patient with Thyroid Cold Nodule?

Thyroid nodule is one of the most common endocrine diseases in the world; it occurs in 4–7% of the general population. Depending on the method of discovery, 4–8% nodules are discovered using palpation, 10–41% with ultrasound (US), and 50% through autopsy where only 20% or less of cold thyroid nodules are caused by cancerous lesions. The aim of this study was to assess US as supporting modality for thyroid scintigraphy to predict malignancy in patient with thyroid cold nodules. In a retrospective study between 2009 and 2013, we analyzed 399 subjects with cold thyroid nodule, where 39 subjects (36 women and 3 men) presented with malignant thyroid cold nodule and 19 subjects underwent US. The US showed malignancy parameters in 8 (42.11%) subjects, while the rest of the 11 (57.89%) subject were benign. Out of all the subjects who underwent US in this study, only 8 (42.11%) subjects shown malignancy characteristics in cold thyroid nodule with papillary thyroid cancer (PTC). That means US parameters of malignant thyroid nodule do not always show up in malignant cold thyroid nodule.

The diagnostic accuracy of ultrasound-guided fine-needle aspiration biopsy for thyroid nodules three centimeters or larger in size

BACKGROUND AND PURPOSE

Whether under ultrasonography (US) guidance or not, fine-needle aspiration biopsy (FNAB) has some limitations, particularly in larger nodules. In this study, we aimed to evaluate the diagnostic value of US-guided fine-needle aspiration biopsy (US-FNAB) in thyroid nodules equal to or larger than 3 cm.

MATERIALS AND METHODS

Data of 267 patients operated for nodular goiter in the period of January 2006 and March 2012 were reviewed retrospectively. The study group (40 males, 104 females; mean age 42.3 ± 12.3, between 17 and 71) consisted of patients with nodules with a diameter of 3 cm or larger. Patients with nodules less than 3 cm in diameter were considered as the control group (27 males, 96 females; mean age 44.4 ± 11.9, between 18 and 71).

RESULTS

For nodules smaller than 3 cm, US-FNAB had an accuracy rate of 60% and a false negativity rate of 21.9%. In nodules equal to or larger than 3 cm, the accuracy rate of US-FNAB was 80%, with a false negativity rate of 6.7%. Malignancy was observed in 16% of the study group and 42.3% of the control group.

CONCLUSION

This study showed that increased nodule diameter is not associated with limitations in the diagnostic value of US-FNAB. We also found that the malignancy rate was smaller for larger nodules. This finding reflects the importance of accurate and rational diagnostic work-up and clinical management for detecting malignancy and surgical decision-making.

Anaplastic carcinoma and toxic multinodular goiter: an unusual presentation

A 70-year-old male was referred with hyperthyroidism and multinodular goiter (MNG). Thyroid ultrasonography showed 2 nodules, one in the isthmus and the other in the left lobe, 51 and 38 mm in diameter, respectively. Neck CT showed a large MNG, thyroid scintigraphy showed increased uptake in the nodule in the left lobe, and fine-needle aspiration biopsy showed a benign cytology of the nodule in the isthmus. The patient declined surgery and was treated with methimazole. After being lost to follow-up for 3 years, the patient returned with complaints of dyspnea, dysphagia, and hoarseness; he was still hyperthyroid. Cervical CT showed a large mass in the isthmus and left lobe with invasion of surrounding tissues, the trachea, the esophagus, and the recurrent laryngeal nerve. Bronchoscopy showed extensive infiltration and compression of the trachea to 20% of its caliber. A tracheal biopsy revealed an anaplastic thyroid carcinoma. The tumor was considered unresectable, and radiotherapy was given. One month later, the patient died. The association between a toxic thyroid nodule and anaplastic thyroid carcinoma has apparently not been reported so far.

Animal models of disease: feline hyperthyroidism: an animal model for toxic nodular goiter

Since first discovered just 35 years ago, the incidence of spontaneous feline hyperthyroidism has increased dramatically to the extent that it is now one of the most common disorders seen in middle-aged to senior domestic cats. Hyperthyroid cat goiters contain single or multiple autonomously (i.e. TSH-independent) functioning and growing thyroid nodules. Thus, hyperthyroidism in cats is clinically and histologically similar to toxic nodular goiter in humans. The disease in cats is mechanistically different from Graves' disease, because neither the hyperfunction nor growth of these nodules depends on extrathyroidal circulating stimulators. The basic lesion appears to be an excessive intrinsic growth capacity of some thyroid cells, but iodine deficiency, other nutritional goitrogens, or environmental disruptors may play a role in the disease pathogenesis. Clinical features of feline toxic nodular goiter include one or more palpable thyroid nodules, together with signs of hyperthyroidism (e.g. weight loss despite an increased appetite). Diagnosis of feline hyperthyroidism is confirmed by finding the increased serum concentrations of thyroxine and triiodothyronine, undetectable serum TSH concentrations, or increased thyroid uptake of radioiodine. Thyroid scintigraphy demonstrates a heterogeneous pattern of increased radionuclide uptake, most commonly into both thyroid lobes. Treatment options for toxic nodular goiter in cats are similar to that used in humans and include surgical thyroidectomy, radioiodine, and antithyroid drugs. Most authorities agree that ablative therapy with radioiodine is the treatment of choice for most cats with toxic nodular goiter, because the animals are older, and the disease will never go into remission.

Serum 8-OHdG and HIF-1α levels: do they affect the development of malignancy in patients with hypoactive thyroid nodules?

Aim of the study

This study aimed to evaluate 8-OHdG and hypoxia-inducible factor 1 (HIF-1α) levels in patients with hypoactive thyroid nodules (toxic multi-nodular goiter, Graves’ disease, and Hashimoto's thyroiditis), as these parameters may be related to oxidative stress and the pathogenesis of cancer.

Material and methods

The study included patients diagnosed with Graves’ disease (n = 20), toxic multinodular goiter (n = 20), and Hashimoto thyroiditis (n = 20), and 20 healthy controls. HIF-1α levels were measured in blood samples and 8-OHdG levels were measured in urine – both via ELISA.

Results

HIF-1α and 8-OHdG levels were significantly higher in the patient groups than in the control group (p < 0.05). In the Hashimoto's thyroiditis patients a correlation was observed between 8-OHdG and thyroglobulin antibodies (p = 0.03). A significant relation was found between 8-OHdG and HIF-1α in the patient group (p < 0.01). Carcinoma was detected in 7 of 43 female patients, but not in any of the male patients. No difference was observed in 8-OHdG or HIF-1α levels between the patients with and without papillary carcinoma (p > 0.05). There was no significant difference in 8-OHdG or HIF-1α levels between the patients with biopsy results that were benign, malignant, and non-diagnostic (p > 0.05).

Conclusions

Serum HIF-1α and urine 8-OHdG levels were significantly higher in the patients with thyroid diseases; however, a relationship with cancer was not observed.

Thyroid cancer in Plummer's disease

Thyroid cancer with concomitant hyperthyroidism is rare. Most foci of malignancy are small and seen postoperatively as incidental findings after surgery for hyperthyroidism. Thyroid masses with clinical features of malignancy and concomitant hyperthyroidism are less-commonly reported. We report two cases of multinodular toxic goitre or Plummer's disease with clinical features of malignancy. Both patients had large multinodular goitres with evidence of metastasis to the manubrium for the first patient and to the lymph node and lungs for the second patient. Both were clinically euthyroid but with free hormone excess and suppressed thyroid stimulating hormone (TSH) on laboratory testing. Both patients received methimazole prior to thyroidectomy. Histopathology revealed follicular variant of papillary cancer with metastasis to the manubrium for the first patient and follicular thyroid cancer with lymph node metastasis for the second. While rare, thyrotoxicosis can occur with malignancy, Plummer's disease may harbour cancer and behave aggressively.

Cancer after thyroidectomy: a multi-institutional experience with 1,523 patients

BACKGROUND

The incidence of thyroid cancer in patients treated operatively for thyroid disease has been historically low (<5%). Previous series have not specifically addressed cancer rates in both euthyroid and hyperthyroid patients. This study examined cancer frequency in patients referred for removal of benign thyroid disease in a multi-institutional series.

STUDY DESIGN

A total of 2,551 patients underwent thyroidectomy at 3 high-volume institutions. Indeterminate/malignant fine-needle aspiration diagnosis was excluded (n = 1,028). Cancer cases were compared among 1,523 patients with Graves' disease (n = 264), nodular goiter (n = 1,095), and toxic nodular goiter (n = 164). Fisher's exact test, chi-square test, Wilcoxon rank sum, Kruskal-Wallis nonparametric t-tests, and multivariable logistic regression were used.

RESULTS

Overall, 238 (15.6%) cancers were recorded: Graves' disease (6.1%), nodular goiter (17.5%), and toxic nodular goiter (18.3%). Cancer rates were significantly different among these groups (p < 0.01) and significantly higher in nodular goiter and toxic nodular goiter vs Graves' disease (p < 0.01); no significant differences in cancer rates were noted among institutions. Overall, 275 patients had thyroiditis (18%). There was a significant association with younger age, male sex, nodular thyroids, and cancer (p < 0.05). Presence of thyroiditis or performance of preoperative fine-needle aspiration was not associated with cancer. Mean cancer size was 1.1 cm (46% >0.5 cm; 39% >1 cm). Most patients underwent total thyroidectomy (80%).

CONCLUSIONS

These data confirm higher than expected incidental thyroid cancer rates (15.6%) in the largest multi-institutional surgical series to date. Nodular thyroids, males, and young patients were more likely to harbor incidental carcinoma. These data support consideration of initial total thyroidectomy as the preferred approach for patients referred to the surgeon with bilateral nodular disease.

Thyroid nodule management: clinical, ultrasound and cytopathological parameters for predicting malignancy

Although fine-needle aspiration cytology is considered to be the reference method for evaluating thyroid nodules, the results are inaccurate in approximately 10-30% of cases. Several studies have attempted to predict the risk of malignancy in thyroid nodules based on age, nodularity, thyrotropin values, thyroid autoimmune disease, hot/cold nodule status, and ultrasound parameters. However, no consensus has been found, and none of these parameters has significantly affected patient management. The management of indeterminate thyroid nodules and re-biopsies of nodules with initially benign cytological results remain important and controversial topics of discussion. The Bethesda cytological system and several studies on the use of molecular markers to predict malignancy from cytological samples of thyroid nodules need further clarification. More in-depth discussions among and continuous education of the specialists involved in treating thyroid disease are necessary to improve the management of these patients. This review aims to examine the clinical, laboratory, ultrasound, and scintigraphic parameters that can be used for thyroid nodule management.

Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists

OBJECTIVE

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This article describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspeciality physicians and others providing care for patients with this condition.

METHODS

The development of these guidelines was commissioned by the American Thyroid Association in association with the American Association of Clinical Endocrinologists. The American Thyroid Association and American Association of Clinical Endocrinologists assembled a task force of expert clinicians who authored this report. The task force examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to develop the text and a series of specific recommendations. The strength of the recommendations and the quality of evidence supporting each was rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' ophthalmopathy; and management of other miscellaneous causes of thyrotoxicosis.

CONCLUSIONS

One hundred evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Guidelines of the French society of endocrinology for the management of thyroid nodules

The present document is a follow-up of the clinical practice guidelines of the French Society of Endocrinology, which were established for the use of its members and made available to scientific communities and physicians. Based on a critical analysis of data from the literature, consensuses and guidelines that have already been published internationally, it constitutes an update of the report on the diagnostic management of thyroid nodules that was proposed in France, in 1995, under the auspices of the French National Agency for Medical Evaluation (l'Agence nationale d'évaluation médicale). The current guidelines were deliberated beforehand by a number of physicians that are recognised for their expertise on the subject, coming from the specialities of endocrinology (the French Thyroid Research Group) and surgery (the French Association for Endocrine Surgery), as well as representatives from the fields of biology, ultrasonography, cytology and nuclear medicine. The guidelines were presented and submitted for the opinion of the members of the Society at its annual conference, which was held in Nice from 7-10 October 2009. The amended document was posted on the website of the Society and benefited from additional remarks of its members. The final version that is presented here was not subjected to methodological validation. It does not claim to be universal in its scope and will need to be revised in concert with progress made in technical and developmental concepts. It constitutes a document that the Society deems useful for distribution concerning the management of thyroid nodules, which is current, efficient and cost effective.

A high level of carcinoembryonic antigen as initial manifestation of medullary thyroid carcinoma in a patient with subclinical hyperthyroidism

Carcinoembryonic antigen (CEA), a tumor marker with a glycoprotein structure, is frequently used in follow-up gastrointestinal malignancies. CEA levels may also increase in neuroendocrine tumors, including medullary thyroid carcinoma (MTC), and in some benign diseases. Patients whose blood tests show high CEA levels should have additional tests regarding MTC. Although MTC comprises only 3%-11% of all thyroid cancers, it should be tested because it has a poor prognosis and may accompany multiple endocrine neoplasia. We present the case of a 76-year-old man with subclinical hyperthyroidism with sporadic MTC who presented with initial high serum CEA levels. He underwent total thyroidectomy and left modified neck dissection. Pathologic specimens stained strongly for CEA. The patient's blood was analyzed for mutations in exons 10, 11, 13, 14, 15, and 16, but the RET proto-oncogene revealed no mutations. The patient was regularly followed by measurement of serum CEA levels and performance of positron emission tomography-computed tomography. Seventeen months after surgery, the patient has remained well and showed no signs of tumor recurrence.

Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This article describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspeciality physicians and others providing care for patients with this condition.

METHODS

The development of these guidelines was commissioned by the American Thyroid Association in association with the American Association of Clinical Endocrinologists. The American Thyroid Association and American Association of Clinical Endocrinologists assembled a task force of expert clinicians who authored this report. The task force examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to develop the text and a series of specific recommendations. The strength of the recommendations and the quality of evidence supporting each was rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' ophthalmopathy; and management of other miscellaneous causes of thyrotoxicosis.

CONCLUSIONS

One hundred evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Clinical review: Incidentally discovered medullary thyroid cancer: diagnostic strategies and treatment

CONTEXT

Medullary thyroid carcinoma (MTC) is diagnosed only after thyroidectomy in approximately 10-15% of cases. This delay in diagnosis can have adverse consequences such as missing underlying pheochromocytoma or hyperparathyroidism in unrecognized multiple endocrine neoplasia type 2 and choosing a suboptimal extent of surgery. Barriers to accurate preoperative diagnosis and management strategies after the discovery of occult MTC are reviewed.

EVIDENCE ACQUISITION

We reviewed PubMed (1975-September 2010) using the search terms medullary carcinoma, calcitonin, multinodular goiter, Graves' disease, calcium/diagnostic use, and pentagastrin/diagnostic use.

EVIDENCE SYNTHESIS

The combined prevalence of occult MTC in thyroidectomy series is approximately 0.3%. Routine calcitonin measurement in goiter patients identifies C-cell hyperplasia as well as MTC. Challenges include interpreting intermediate values and unavailability of pentagastrin stimulation testing in the United States. Early studies have begun to identify appropriate cutoff values for calcium-stimulated calcitonin. For management of incidentally discovered MTC, we highlight the role of early measurement of calcitonin and carcinoembryonic antigen, RET testing, and comprehensive neck ultrasound exam to direct further imaging, completion thyroidectomy, and lymph node dissection.

CONCLUSIONS

Occult MTC is an uncommon, but clinically significant entity. If calcium stimulation testing cutoff data become well-validated, calcitonin screening would likely become more widely accepted in the diagnostic work-up for thyroid nodules in the United States. Among patients with incidental MTC, those with persistently elevated serum calcitonin levels, positive RET test, or nodal disease are good candidates for completion thyroidectomy and lymph node dissection in selected cases, whereas patients with undetectable calcitonin, negative RET testing, and no sonographic abnormalities often may be watched conservatively.

Selenoenzymes, laboratory parameters, and trace elements in different types of thyroid tumor

This study was performed to investigate selenoenzyme activities and trace element concentrations in thyroid tissues, with reference to other parameters routinely used to characterize thyroid function. This was to reveal relevant parameters as possible additional markers of tumor grade, clinical course, and prognosis of thyroid disorders. The tissue samples were obtained during surgical treatment (total or near total thyroidectomy) of 122 patients with different types of thyroid tumor. For most of the investigated parameters in different groups of patients, we did not find statistically significant differences. In the majority of cases, thyroid benign or malignant tumors were not accompanied by significant derangement of the gland selenoenzymes and of either intrathyroidal or plasma concentration of selenium. Nevertheless, types I and II iodothyronine deiodinases were the most promising (among selenoenzymes) targets for diagnoses and possibly therapy of thyroid tumors. Higher activities of both enzymes in cases with Graves' disease, as compared with other thyroid lesions, suggest their involvement in the pathogenesis of this condition. Patients with struna nodosa had higher levels of thyroid Zn, Cu, and Pb as compared with papillary carcinoma subjects and also a higher level of Cu than follicular carcinoma cases. The above diagnostics may play a similar role to some of the general thyroid function indices, TSH, anti-TG, anti-TPO, and calcitonin, which can partially distinguish between various thyroid tumors. In conclusion, some of selenium status markers, when accompanied with general parameters, and trace elements can serve as factors with pathophysiologic relevance and be helpful in the identification of malignant disease. Multivariate statistical methods should be employed to tackle a broad array of thyroid tumor diagnostic data in a short time. Partial least squares model and other pattern recognition methods seem to be the most appropriate methods for that task. The miniaturization of all the steps of complex analytical procedure should be developed in a way to allow its completion as sensitive, robust, and efficient for use of the small quantity of material provided by fine-needle biopsy.

Do benign thyroid nodules have malignant potential? An evidence-based review

BACKGROUND

Benign thyroid tumors account for most nodular thyroid disease. Determination of whether a thyroid nodule is benign or malignant is a major clinical dilemma and underlies the decision to proceed to surgery in many patients. Although the accuracy of thyroid nodule fine-needle aspiration (FNA) has reduced the need for surgery over the years, questions regarding how to follow FNA-designated benign nodules remain unresolved. This is true at least in part because of uncertainty over whether some benign nodules harbor malignant potential.

METHODS

An evidence-based review of recent clinical, pathologic, and molecular data is presented. A summary of data and observations from our own experience is also provided.

RESULTS

Review of our recent 10-year experience indicates that 2% of thyroid malignancies arise within a preexisting benign thyroid nodule. In addition, both cytologic and molecular tumor markers, including Gal-3, CITED1, HBME-1, Ras, RET/PTC, and PAX8/PPAR gamma, have been identified in some histopathologically classified benign nodules. Gene expression profiling suggests that follicular adenomas and Hürthle cell adenomas have similarities to both benign and malignant tumors, suggesting that some of these tumors are premalignant. In addition, 10% of surgically excised follicular tumors are encapsulated follicular lesions with nuclear atypia, which have been termed "well-differentiated tumors of uncertain malignant potential." The data available suggest that these tumors could be precursors to carcinoma.

CONCLUSION

Some benign thyroid nodules have malignant potential. Further molecular testing of these tumors can shed light on the pathogenesis of early malignant transformation.