Solitary thyroid nodule: a prospective evaluation of nuclear scanning and ultrasonography

Thyroid ultrasound features and risk of carcinoma: a systematic review and meta-analysis of observational studies

BACKGROUND

Thyroid nodules are a common finding in the general population, and their detection is increasing with the widespread use of ultrasound (US). Thyroid cancer is found in 5-15% of cases depending on sex, age, and exposure to other risk factors. Some US parameters have been associated with increased risk of malignancy. However, no characteristic seems sufficiently reliable in isolation to diagnose malignancy. The objective of this meta-analysis was to evaluate the diagnostic performance of US features for thyroid malignancy in patients with unselected thyroid nodules and nodules with indeterminate fine-needle aspiration (FNA) cytology.

METHODS

Electronic databases were reviewed for studies published prior to July 2012 that evaluated US features of thyroid nodules and reported postoperative histopathologic diagnosis. A manual search of references of review and key articles, and previous meta-analyses was also performed. A separate meta-analysis was performed including only nodules with indeterminate cytology. Analyzed features were solid structure, hypoechogenicity, irregular margins, absence of halo, microcalcifications, central vascularization, solitary nodule, heterogeneity, taller than wide shape, and absence of elasticity.

RESULTS

Fifty-two observational studies (12,786 nodules) were included. Nine studies included nodules with indeterminate cytology as a separate category, comprising 1851 nodules. In unselected nodules, all US features were significantly associated with malignancy with an odds ratio varying from 1.78 to 35.7, and microcalcifications, irregular margins, and a taller than wide shape had high specificities (Sp; 87.8%, 83.1%, 96.6%) and positive likelihood ratios (LHR; 3.26, 2.99, 8.07). Absence of elasticity was the single feature with the best diagnostic performance (sensitivity 87.9%, Sp 86.2%, and positive LHR 6.39). The presence of central vascularization was the most specific US feature in nodules with indeterminate cytology (Sp 96% and positive LHR 2.13).

CONCLUSIONS

US features in isolation do not provide reliable information to select nodules that should have a FNA performed. A combination of US characteristics with higher likelihood ratios and consequently with higher post-test probabilities of malignancy-microcalcifications, or a taller than wide shape, or irregular margins, or absence of elasticity-will probably identify nodules with an increased risk for malignancy. Further studies are required to standardize elastography techniques and evaluate outcomes, especially in nodules with an indeterminate cytology.

Assessment of nodular goitre

Nodular goitres are enlargements of the thyroid gland. In the absence of thyroid dysfunction, autoimmune thyroid disease, thyroiditis and thyroid malignancy, they constitute an entity described as non-toxic nodular goitre, which occurs both endemically and sporadically. In the early phase of goitrogenesis, goitres are diffuse and, with time, such goitres tend to become nodular. Concomitantly, thyroid function often becomes autonomous, and therefore the patients gradually develop hyperthyroidism. Some non-toxic goitre patients have no symptoms at all, or just complaints of cosmetic disfigurement. In the diagnostic evaluation protocol, neck palpation and several imaging methods are available: ultrasonography (US), the new developed US elastography, scintigraphy, computed tomography (CT) scan and magnetic resonance imaging (MRI). Fine-needle aspiration biopsy (FNAB) provides the most direct and specific information about a thyroid nodule. Recently, a combination of cytology and molecular testing has shown significant improvement in the diagnostic accuracy and allowed for better prediction of malignancy in thyroid nodular disease.

Differentiated Pediatric Thyroid Cancer: Correlates With Adult Disease, Controversies in Treatment

The biologic behavior of differentiated thyroid cancer can differ between adults and children, especially in those children younger than 10 years of age. Unlike adults, young children typically present with advanced disease at diagnosis. Despite this, children respond rapidly to therapy and have an excellent prognosis that is significantly better than that of their adult counterparts with advanced disease. In contradistinction to adults, children with thyroid cancer also have higher local and distant disease recurrences with progression-free survival of only 70% at 5 years, mandating life-long surveillance. Although thyroid cancer is the most common carcinoma in children, overall incidence is low, a factor that has prevented performance of a controlled, randomized, prospective study to determine the most efficacious treatment regimen in this age group. So, although extensively investigated, treatment of pediatric patients with differentiated thyroid cancer remains controversial. This article reviews the current controversies in the treatment of pediatric differentiated thyroid cancer, focusing on issues of optimal initial and subsequent therapy as well as that of long-term follow-up. Our approach to treatment is presented. In so doing, similarities and differences between adults and children with differentiated thyroid cancer as regards unique considerations in epidemiology, diagnosis, staging, treatment, therapy-related late effects, and disease surveillance are presented. The expanding use of and appropriate roles for thyrogen and fluorine-18-fluorodeoxyglucose positron emission tomography in disease evaluation and surveillance will be addressed.

Management of simple nodular goiter: current status and future perspectives

The simple nodular goiter, the etiology of which is multifactorial, encompasses the spectrum from the incidental asymptomatic small solitary nodule to the large intrathoracic goiter, causing pressure symptoms as well as cosmetic complaints. Its management is still the cause of considerable controversy. The mainstay in the diagnostic evaluation is related to functional and morphological characterization with serum TSH and (some kind of) imaging. Because malignancy is just as common in patients with a multinodular goiter as patients with a solitary nodule, we support the increasing use of fine-needle aspiration biopsy (cytology). Most patients need no treatment after malignancy is ruled out. In case of cosmetic or pressure symptoms, the choice in multinodular goiter stands between surgery, which is still the first choice, and radioiodine if uptake is adequate. In addition to surgery, the solitary nodule, whether hot or cold, can be treated with percutaneous ethanol injection therapy. If hot, radioiodine is the therapy of choice. Randomized studies are scarce, and the side effects of nonsurgical therapy are coming into focus. Therefore, the use of the optimum option in the individual patient cannot at present be based on evidence. However, we are of the view that levothyroxine, although widely used, should no longer be recommended routinely for this condition. Within a few years, the introduction of recombinant human TSH and laser therapy may profoundly alter the nonsurgical treatment of simple nodular goiter.

Endocrine tumors: evaluation of the thyroid nodule

Thyroid nodules are found in 4 to 7% of the population, and with the increased use of radiographic methods, incidental nodules are becoming more prevalent. Only 5% of all nodules will be malignant, and thyroid cancer accounts for only 0.4% of all cancer deaths. The preferred diagnostic approach is early referral, avoidance of numerous radiologic evaluations, and early performance fine-needle aspiration. This article reviews the literature of the last 12 months and discusses some of the new molecular, genetic, and immunostaining techniques in the evaluation of thyroid nodules.

A comparative study of fine needle aspiration cytology, ultrasonography and radionuclide scan in the management of solitary thyroid nodule : A prospective analysis of fifty cases

Solitary thyroid nodule is a common clinical entity encountered by the otorhinolaryngologist and physcians. The optimum diagnostic strategy for the euthyroid patient with a soilitary thyroid nodule is still a matter of debate. The goal of diagnostic workup now is to select those patients for surgery who have a high likelihood of harbouring malignancy in the solitary thyroid nodule. The present study was undertaken to evaluate the utility of FANC in the preoperative diagnosis of solitary thyroid nodule and to evaluate the efficacy of FNAC, VSG and RNS in differentiating between benign and malignant nodules. It was found that FNAC is a safe, reliable and cost effective diagnostic modality with a high sensitivity of 83.3% and specificity of 100% and is the single best investigation for preoperative evaluation of solitary thyroid nodules to differentiate between benign and malignant nodules.

Thyroid nodules: diagnosis and therapy

Less than 1% of all cancers are present in the thyroid, yet thyroid nodules are found in 4 to 10% of the adult population. Because thyroid nodules are relatively common, the diagnostic dilemma is to distinguish between a more common benign nodule, which usually does not require specific treatment, and a malignant nodule, which requires thyroidectomy and further treatment. Thyroid nodules usually are an incidental finding on a routine examination by a primary care physician. When patients seek treatment for symptomatic nodules, a more serious problem may be indicated, and thyroid cancer is suggested. However, additional studies have demonstrated the use of genetic markers and immunohistochemistry in the diagnosis of thyroid nodules, which may lead to a more rational approach to the treatment. This article reviews literature published in the last 12 months pertaining to the pathogenesis, diagnosis, and treatment of thyroid nodules.

An evaluation of thallium imaging for detection of carcinoma in clinically palpable solitary, nonfunctioning thyroid nodules

OBJECTIVE

An evaluation of thallium imaging for differentiating benign from malignant lesions in clinically palpable solitary, nonfunctioning, thyroid nodules.

METHODS

Seventy-eight patients presenting with a clinically palpable solitary nonfunctioning thyroid nodule were imaged with 3 mCi thallium-201 with a pinhole acquisition at 20 minutes and 3 hours after injection. Thallium uptake was assessed as grade 1, less than the rest of the gland; grade 2, same as the rest of the gland; and grade 3, more than the rest of the gland. All patients underwent surgery and the histology was compared with the thallium scan results.

RESULTS

Of the 78 patients presenting with solitary thyroid nodule, 13 were malignant and 65 were benign. Twenty-four patients with benign disease showed no uptake of thallium at 3 hours (grade 1). Thirty-two patients with benign disease and 2 patients with malignant lesion had grade 2 uptake at 3 hours. Eleven patients with malignant disease and 9 with benign disease had grade 3 uptake at 3 hours.

CONCLUSIONS

All malignant lesions had at least grade 2 and most had grade 3 uptake at 3 hours. All lesions with grade 1 uptake at 3 hours were benign, enabling malignancy to be excluded in one-third of cases. Thallium imaging is a useful adjunct to fine-needle cytology in evaluation of solitary thyroid nodules especially when the latter is inconclusive.

Relative risk of cancer in sonographically detected thyroid nodules with calcifications

PURPOSE

The aim of this prospective study was to evaluate the significance of sonographically detected thyroid calcifications in the diagnosis of thyroid cancer.

METHODS

One hundred eighty-eight patients with thyroid disease, including 37 with thyroid cancer, were included in the study. Each patient underwent preoperative, high-resolution sonography to evaluate the thyroid gland for the presence of calcifications.

RESULTS

The highest incidence of calcification was found in thyroid cancer (54%), followed by multinodular goiter (40%), solitary nodular goiter (14%), and follicular adenomas (12%). The incidence of cancer was significantly higher in calcified nodules (29%) than in noncalcified nodules in the entire group (14%) (p = 0.019), with a relative risk of 2.5. In the group of solitary thyroid nodules, the incidence of cancer in the calcified nodules (55%) was higher than in the nodules without calcification (23%) (p = 0.016). Multiple noncalcified thyroid nodules harbored cancer in only 5% of cases. Compared with multiple noncalcified thyroid nodules, the solitary calcified nodules demonstrated a relative risk of 22.8. In both the solitary and multiple nodules, the relative risk in the presence of calcification was about the same, around 4. Patients younger than 40 years with calcified nodules constituted a high-risk group, with a relative risk of 3.8 versus 2.5 in patients older than 40 years with calcified nodules.

CONCLUSIONS

The detection of thyroid calcifications by sonography is diagnostically valuable, especially in cases involving a solitary nodule or a young person. The presence of calcifications in these cases should raise the suspicion of malignancy. The low incidence of cancer in patients with multiple noncalcified thyroid nodules suggests that a more conservative approach may be appropriate in such cases.

Abordagem clínica e laboratorial do bócio uninodular sólido: vantagens da determinação da calcitonina sérica por métodos distintos no rastreamento do carcinoma medular de tireóide, forma esporádica

A apresentação clínica mais freqüente da forma esporádica do carcinoma medular da tireóide (CMT) é o bócio uninodular sólido (BUS), apresentação esta semelhante aos demais tumores que afetam a glândula. O estabelecimento da freqüência de CMT em BUS apresenta implicações importantes não só diagnosticas, como também terapêuticas, visto a abordagem cirúrgica do CMT diferir de outros tumores tireoideanos. Para investigar a prevalência de CMT em BUS, dosamos calcitonina (CT) sérica, marcador bioquímico do CMT, por métodos distntos (RIA e IRMA) em 60 casos (55 mulheres; com idades entre 22 e 75 anos). A análise citológica obtida através de punção biópsia (PAAF) revelou 100% de especificidade e 67% de sensibilidade na detecção de carcinoma de tireóide. Considerando-se o grau de suspeita clínica para neoplasia tireoideana e os achados anatomopatológicos, houve 60% de correlação positiva. CMT foi diagnosticado através da elevação da CT sérica em um dos 59 casos (1,69%) e confirmado posteriormente pela PAAF e anatomopatológico. A incidência de CMT entre os casos de neoplasias tireoideanas nesta amostra foi de 12,5% (1/8). Concluímos que a dosagem rotineira da CT sérica em casos com BUS não só complementa o estudo desta doença, como auxilia fortemente no diagnóstico do CMT. Tanto o IRMA como o RIA mostraram-se métodos úteis no rastreamento do CMT. Entretanto, o RIA pode provavelmente detectar ainda mais precocemente a elevação de formas não monoméricas da molécula de CT, as quais nos casos de CMT são usualmente mais abundantes que as formas monoméricas.

Value of repeated fine-needle aspiration cytology and cytologic experience on the management of thyroid nodules

Although fine-needle aspiration is being currently accepted as the most reliable method to select patients with thyroid nodules for surgery, controversy remains about the accuracy in distinguishing benign nodules. We present our results from 636 fine-needle aspirations performed from 1984 to 1989. Our article focuses on the value of cytologic expertise and repeated punctures for follow-up of benign nodules. We found annual figures for specificity and positive predictive value to increase steadily from 1984 to 1989, thus suggesting that the power of the test is proportional to the experience of the cytologist. We also state that the value of performing repeated punctures for the follow-up of unselected benign nodules is low.

Thyroid nodules in childhood and adolescence--thirty years of experience

In the thirty year period between 1966 and 1996, fifty-two patients underwent surgery for thyroid nodules at the Royal Children's Hospital, Melbourne. We aimed to review their presentation, investigation, histology, treatment and to follow up those who had malignant neoplasms. Forty-one of the fifty-two patients presented with a single thyroid nodule. Investigations performed included thyroid function tests (N = 32), thyroid autoantibodies (N = 21), an ultrasound of the thyroid (N = 26) and 99mTechnetium scanning (N = 32). Thirty-five of the neoplasms were benign, the follicular adenoma (N = 16) being the most common. Seventeen patients had malignant neoplasms, seven of whom had papillary and seven of whom had follicular carcinoma. Three patients had medullary carcinoma of the thyroid. Nine of the seventeen patients with thyroid malignancy received post-operative 131I treatment. At the time of this review, all patients were living.

Ultrasonography for thyroid screening after head and neck irradiation in childhood cancer survivors

We prospectively used ultrasonography to detect thyroid abnormalities in 96 long-term survivors of childhood cancer, who received head and neck radiation therapy at a median age of 8.9 years. The median time interval since irradiation was 10.8 years (range 5.6-22.8 years). Most survivors of leukemia received 24 Gy cranial irradiation for central nervous system prophylaxis; patients with solid tumors received between 20 and 66 Gy (median 37.5 Gy). The total evaluation included clinical history, physical examination, thyroid function tests, and thyroid ultrasonography; radionuclide scans were performed in patients whose abnormalities persisted on subsequent ultrasound exams. Clinical history and physical examination revealed thyroid abnormalities in 14 patients (15%), but ultrasound detected abnormalities in 42 patients (44%). These findings included inhomogeneity (n = 29), cysts (n = 15), and nodules (n = 22) and occurred in nearly half of patients treated with 15 Gy or more directly to the thyroid gland. Radionuclide scans confirmed the presence of thyroid nodules in 13 of 15 patients with ultrasonographic evidence of nodules. Six patients had thyroid neoplasia, including one case of papillary carcinoma. All patients with neoplasia had nodules demonstrated on ultrasonography. Our experience suggests that in childhood cancer survivors, ultrasonography is a sensitive, affordable, and noninvasive means of detecting subtle parenchymal abnormalities. We recommend thyroid ultrasonography for childhood cancer survivors who received head and neck irradiation. A baseline study should be obtained within 1 year of completion of therapy. The frequency of subsequent examinations should be based on the radiation dose and the patient's age at the time of irradiation.

Thyroid imaging with Tc-99m MIBI in patients with solitary cold single nodules on pertechnetate imaging

Thyroid imaging was performed in 30 patients with the standard pertechnetate technique, as well as with Tc-99m MIBI using a double-phase acquisition protocol. All patients had normal thyroid function confirmed by hormone measurements and cold solitary thyroid nodules, which were evaluated by pertechnetate scanning. Tc-99m MIBI scans were reported as showing cold (N = 14), warm (N = 7), or hot (N = 9) nodules. Nodule classification was made according to fine needle aspiration biopsy findings in 20 patients. The remaining 10 proceeded to surgery and had histopathologic confirmation of their lesions. Although all cold nodules with Tc-99m MIBI were cystic, six of the warm nodules were benign lesions. No histologically proven benign nodule was hot with Tc-99m MIBI. Of the hot nodules, seven were suspicious for follicular carcinoma with fine needle aspiration biopsy (N = 3), or had histologically proven papillary carcinoma (N = 4). Delayed images in five of seven of these lesions showed nodular retention of the radiopharmaceutical. In conclusion, double-phase Tc-99m MIBI scanning of the thyroid gland could be helpful in the preoperative assessment of patients with cold solitary thyroid nodules in order to evaluate the malignancy probability of these lesions.

Goitre in Australia

Goitre due to nodular thyroid disease is common. Most patients present with benign disease and are euthyroid at presentation, but careful clinical evaluation (thyroid function tests and fine needle biopsy) is essential to determine appropriate therapy. Thyroid hormone therapy should be reserved for hypothyroid patients and those with Hashimoto's thyroiditis. Iodine supplements are not beneficial. Indications for surgery are a malignant or atypical finding on fine needle biopsy, a recurrent cyst larger than 4 cm in diameter, or a goitre causing obstruction.

Limitations of thyroid scanning in solitary thyroid nodules

During an 8-year period, 104 patients (19 males, 85 females) underwent surgery for a solitary thyroid nodule. There were 19 (18.3%) malignant nodules and 85 (81.7%) benign nodules. Malignancy occurred in 3 (15.8%) males and 16 (18.8%) females. Pre-operative scanning was performed prior to referral in 59 patients (52 had ultrasound, 41 had isotope scanning; the majority had both). Of the scanned patients, 12 (20%) had a malignant nodule while 7 (15.5%) of the 45 patients who did not have scanning had a malignant nodule. In patients who had an ultrasound scan, malignancy was found in 5 (23.8%) of the 21 solid nodules and 7 (22.7%) of the 31 cystic (or solid/cystic) nodules. In patients who had thyroid isotope scanning, malignancy was found in 6 (17.5%) of the 34 cold (non-functioning) nodules and 3 (43%) of the 7 warm or hot (functioning) nodules. Ultrasound and isotope scanning may be misleading and neither help to differentiate benign from malignant thyroid nodules which require surgical excision.

Preoperative diagnostic tests for operable thyroid disease

Although the availability and acceptance of fine-needle aspiration biopsy (FNAB) of thyroid nodules has increased, many physicians still use thyroid scintigraphy for distinguishing benign from malignant lesions. We evaluated these diagnostic tests in 350 patients who had thyroid surgery in our institution between 1977 and 1990. Histologic confirmation of FNAB was obtained in 265 patients. In the group of patients having surgery, 247 thyroid scintigraphies were performed. Our patients were divided into two groups (1977-1986 and 1986-1990). The first group comprised 173 patients with 173 FNABs and 126 scintigrams. The second group consisted of 177 patients having 92 FNABs and 121 scintigrams. Results of scintigrams were analyzed in the second group only. In 5 out of 120 cases where the FNAB result was "benign or probably benign" the lesion appeared to be malignant postoperatively. If the FNAB result was "malignant or probably malignant" (n = 83) the pathology report confirmed a malignancy in 68 cases (81.9%). In 56 instances of all 265 FNABs the cytology report was not conclusive ("uncertain"); in 21.4% of these cases a malignancy was found postoperatively. An FNAB-result "(probably) malignant" had a positive predictive value of 0.819 while the negative predictive value of a result "(probably) benign" is 0.950. An "uncertain" result does not take away our concern so this result should have the same consequences as those of a result "(probably) malignant". In that case, FNAB-sensitivity is 93.0% and specificity 66.1%. Eighty-five of the last 116 scintigraphies showed a solitary node. Eleven of these nodes were hot while 74 were cold.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of ultrasound in the management of thyroid nodules

One hundred twenty patients undergoing thyroid surgery for thyroid nodules or goiter were examined by preoperative ultrasound and fine needle aspiration (FNA) cytology. In the determination of whether a lesion was malignant, FNA had sensitivity, specificity, and positive predictive values of 86%, 85%, and 58%, respectively. Ultrasound had sensitivity, specificity, and positive predictive values of 74%, 83%, and 51%, respectively. The different types of thyroid pathology showed different ultrasonic features in most cases, although no single feature was pathognomonic. Malignant lesions tended to be solid and hypoechoic without a halo, but there was a cystic element in 26% of the lesions and calcification in 37%. Ultrasound was superior to FNA in diagnosing nodular goiter with sensitivity, specificity, and positive predictive values of 70%, 93%, and 92%, respectively, compared with 55%, 86%, and 83%, respectively. The two modalities are complementary.