High-resolution real-time ultrasonography of thyroid nodules

Clinicoradiological Characteristics in the Differential Diagnosis of Follicular-Patterned Lesions of the Thyroid: A Multicenter Cohort Study

OBJECTIVE

Preoperative differential diagnosis of follicular-patterned lesions is challenging. This multicenter cohort study investigated the clinicoradiological characteristics relevant to the differential diagnosis of such lesions.

MATERIALS AND METHODS

From June to September 2015, 4787 thyroid nodules (≥ 1.0 cm) with a final diagnosis of benign follicular nodule (BN, n = 4461), follicular adenoma (FA, n = 136), follicular carcinoma (FC, n = 62), or follicular variant of papillary thyroid carcinoma (FVPTC, n = 128) collected from 26 institutions were analyzed. The clinicoradiological characteristics of the lesions were compared among the different histological types using multivariable logistic regression analyses. The relative importance of the characteristics that distinguished histological types was determined using a random forest algorithm.

RESULTS

Compared to BN (as the control group), the distinguishing features of follicular-patterned neoplasms (FA, FC, and FVPTC) were patient's age (odds ratio [OR], 0.969 per 1-year increase), lesion diameter (OR, 1.054 per 1-mm increase), presence of solid composition (OR, 2.255), presence of hypoechogenicity (OR, 2.181), and presence of halo (OR, 1.761) (all p < 0.05). Compared to FA (as the control), FC differed with respect to lesion diameter (OR, 1.040 per 1-mm increase) and rim calcifications (OR, 17.054), while FVPTC differed with respect to patient age (OR, 0.966 per 1-year increase), lesion diameter (OR, 0.975 per 1-mm increase), macrocalcifications (OR, 3.647), and non-smooth margins (OR, 2.538) (all p < 0.05). The five important features for the differential diagnosis of follicular-patterned neoplasms (FA, FC, and FVPTC) from BN are maximal lesion diameter, composition, echogenicity, orientation, and patient's age. The most important features distinguishing FC and FVPTC from FA are rim calcifications and macrocalcifications, respectively.

CONCLUSION

Although follicular-patterned lesions have overlapping clinical and radiological features, the distinguishing features identified in our large clinical cohort may provide valuable information for preoperative distinction between them and decision-making regarding their management.

Imaging Surveillance in Patients After a Benign Fine-Needle Aspiration Biopsy of the Thyroid: Associated Cost and Incidence of Subsequent Cancer

OBJECTIVE

The objective of our study was to determine patterns and cost of imaging tumor surveillance in patients after a benign fine-needle aspiration (FNA) biopsy of the thyroid in a large teaching hospital as well as the rate of subsequent cancer detection.

MATERIALS AND METHODS

This cohort study was approved by the appropriate institutional review board and complied with HIPAA. All patients who had a benign thyroid FNA biopsy between January 1, 1999, and December 31, 2003, were identified from an institutional pathology database. We gathered information from electronic medical records on imaging tumor surveillance and subsequent cancer detection. Cost was determined using the facility total relative value unit and the 2014 Hospital Outpatient Prospective Payment System conversion factor.

RESULTS

Between January 1, 1999, and December 31, 2003, 1685 patients had a benign thyroid FNA biopsy, 800 (47.5%) of whom underwent follow-up imaging. These patients underwent 2223 thyroid ultrasound examinations, 606 ultrasound-guided thyroid FNA biopsies, 78 thyroid scintigraphy examinations, 168 neck CTs, and 53 neck MRIs at a cost of $529,874, $176,157, $39,622, $80,580, and $53,114, respectively, for a total cost of $879,347 or $1099 per patient. The mean length of follow-up was 7.3 years, during which time 19 (2.4%) patients were diagnosed with thyroid cancer at a cost of $46,281 per cancer. Seventeen (89.5%) were diagnosed with papillary carcinoma and two (10.5%) with Hurthle cell carcinoma.

CONCLUSION

Over a 5-year period, about half of the patients who had a benign thyroid FNA biopsy underwent follow-up imaging at considerable cost with a small rate of subsequent malignancy.

Ultrasonography Diagnosis and Imaging-Based Management of Thyroid Nodules: Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations

The rate of detection of thyroid nodules and carcinomas has increased with the widespread use of ultrasonography (US), which is the mainstay for the detection and risk stratification of thyroid nodules as well as for providing guidance for their biopsy and nonsurgical treatment. The Korean Society of Thyroid Radiology (KSThR) published their first recommendations for the US-based diagnosis and management of thyroid nodules in 2011. These recommendations have been used as the standard guidelines for the past several years in Korea. Lately, the application of US has been further emphasized for the personalized management of patients with thyroid nodules. The Task Force on Thyroid Nodules of the KSThR has revised the recommendations for the ultrasound diagnosis and imaging-based management of thyroid nodules. The review and recommendations in this report have been based on a comprehensive analysis of the current literature and the consensus of experts.

Association between idiopathic retroperitoneal fibrosis and autoimmune thyroiditis: a case-control study

BACKGROUND

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease often associated with autoimmune disorders. Whether IRF is associated with Hashimoto's thyroiditis (HT) is poorly understood and only addressed by case-reports. We evaluated the prevalence of HT in a large IRF cohort and in matched controls.

METHODS

We studied 73 consecutive patients with new-onset IRF and 71 controls. The association between HT and IRF was cross-sectionally evaluated in a referral center. Longitudinally, thyroid function tests were also performed. Serum concentrations of FT4, TSH, and anti-thyroperoxidase antibodies (AbTPO) were evaluated together with thyroid ultrasound (US). Lymphocytic infiltrates were characterized in thyroid nodule fine needle aspirates (FNAB). In patients undergoing thyroidectomy, thyroid histology was also reviewed.

RESULTS

A higher prevalence of AbTPO positivity (P<0.03) and US findings suggestive of autoimmune thyroiditis (US-AIT) (P<0.0001) were found in IRF patients compared to controls. In the logistic regression analysis, the risk of AbTPO-diagnosed HT and that of US-AIT was significantly higher in IRF patients than in controls (ORs, 3.56, 95% CI 1.48-8.59, P=0.004 and 4.74, 95% C.I., 2.34-9.61, P<0.0001 in AbTPO-diagnosed HT and US-AIT, respectively). Thyroid histology in IRF patients showed either classical or the fibrous variant of HT. At the end of the follow-up (median, 45 and 36 months in patients and controls, respectively), 25% of IRF patients and 3% of controls were receiving l-thyroxine.

CONCLUSIONS

IRF patients have a higher risk of HT compared to controls. Thyroid function should be monitored in patients with IRF.

Diagnosis of endocrine disease: thyroid ultrasound (US) and US-assisted procedures: from the shadows into an array of applications

In patients with thyroid nodules, ultrasound (US) imaging represents an indispensable tool for assessment of the risk of malignancy. Over approximately four decades, innovative technology and successive improvements have facilitated its entry into the routine management and greatly improved its predictive value. When US features cannot reliably rule out thyroid cancer, US guidance allows a correct and safe sampling also of small or deeply located thyroid lesions. Obtained in this way, cytological or microhistological specimens may reliably define the nature of most thyroid nodules, and the information from histochemical or molecular markers shows promise in the classification of the remaining indeterminate cases. While a prompt surgical treatment can be offered in the minority of suspicious or definitely malignant cases, most individuals warrant only a follow-up. However, at initial evaluation, or over the years, a fraction of these benign lesions may grow and/or become symptomatic. Such cases may benefit from US-guided minimally invasive procedures as an alternative to surgery. Image-guided percutaneous treatments most often achieve relief of neck complaints, are inexpensive, and can be performed on an outpatient basis. The risk of major complications, after adequate training, is very low. Importantly, thyroid function is preserved. Currently, percutaneous ethanol injection for cystic lesions and thermal ablation, with laser or radiofrequency, for solid nodules are increasingly used and disseminated beyond the initial core facilities. In centres with expertise and high patient volume, their use should be considered as first-line treatment alternatives to surgery for selected patients with benign enlarging or symptomatic thyroid lesions.

US-guided percutaneous radiofrequency thermal ablation for the treatment of solid benign hyperfunctioning or compressive thyroid nodules

The aim of the study was to define the effectiveness and safety of ultrasound-guided percutaneous radiofrequency (RF) thermal ablation in the treatment of compressive solid benign thyroid nodules. Thirty-one patients not eligible for surgery or radioiodine (131I) treatment underwent RF ablation for benign nodules; a total of 33 nodules were treated (2 patients had 2 nodules treated in the same session): 10 cold nodules and 23 hyperfunctioning. Fourteen patients complained of compressive symptoms. Nodule volume, thyroid function and compressive symptoms were evaluated before treatment and at 1, 3 and 6 mo. Ultrasound-guided RF ablation was performed using a Starbust RITA needle, with nine expandable prongs; total exposure time was 6 to 10 min at 95 degrees C in one area or more of the nodule. Baseline volume (measured at the time of RF ablation) was 27.7 +/- 21.5 mL (mean +/- SD), but significantly decreased during follow-up: 19.2 +/- 16.2 at 1 mo (-32.7%; p < 0.001), 15.9 +/- 14.1 mL at 3 mo (-46.4 %; p < 0.001) and 14.6 +/- 12.6 mL at 6 mo (-50.7%; p < 0.001). After treatment, all patients with cold nodules remained euthyroid: five patients with hot nodules normalized thyroid function, and the remaining sixteen showed a partial remission of hyperthyroidism. Besides a sensation of heat and mild swelling of the neck, no major complications were observed. Improvement in compressive symptoms was reported by 13 patients, with a reduction on severity scale from 6.1 +/- 1.4 to 2.2 +/- 1.9 (p < 0.0001). Radiofrequency was effective and safe in reducing volume by about 50% and compressive symptoms in large benign nodules. Hyperfunction was fully controlled in 24% of patients and partially reduced in the others.

Clinical features and therapeutic implication of papillary thyroid microcarcinoma

Papillary thyroid microcarcinomas (PTMs) are small tumors (< or =1 cm of diameter) that belong to the well-differentiated low-risk carcinomas of the thyroid, which are characterized by benign behavior, probably of little clinical significance, and do not affect patients' survival. They are found in otherwise normal thyroids or in multinodular goiters with a clinical frequency varying substantially according to different series. Sometimes, PTM may be associated with lymph node metastases at presentation and/or locoregional recurrences during follow-up. Distant metastases are extremely rare, but have been reported. Although deaths related to PTM are almost unknown, PTM raises therapeutic implications. This review addresses the issue of definition, treatment, and follow-up of PTM.

Diagnostic value of ultrasonography to distinguish between benign and malignant lesions in the management of thyroid nodules

OBJECTIVE

We analyzed the sonographic characteristics of thyroid nodules and assessed the diagnostic value of ultrasonography in order to distinguish between benign and malignant lesions in terms of the management of thyroid nodules.

DESIGN

We retrospectively analyzed the sonographic features of thyroid nodules in 580 patients who had been examined with fine-needle aspiration cytology or who underwent surgery for a thyroid nodule. The sonographic features that suggested malignancy include microcalcifications, an irregular or microlobulated margin, marked hypoechogenicity, and a shape that was taller than it was wide. The presence of one or more of these features indicated classification as category 3 (malignant). The absence of all of these features indicated classification as category 2 (benign). Presence of an anechogenic cystic nodule was classified as category 1 (benign).

MAIN OUTCOME

Of 124 lesions classified as category 3, 60 of the lesions were malignant. Of 418 lesions classified as category 1 or 2, 409 were benign. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy based on the sonographic classification method were 87.0%, 86.5%, 48.4%, 97.8%, and 86.5%, respectively.

CONCLUSIONS

Our results identified this sonographic classification as a useful tool in the differentiation of malignant nodules from benign nodules. In view of the high negative predictive value of sonographic classification, a more aggressive approach is recommended only for category 3 nodules.

The effect of surgical office-based thyroid ultrasound on clinical decision making

An important diagnostic tool for the evaluation of thyroid disease, thyroid ultrasound has recently become available for use in surgical offices. The purpose of this report is to determine the lesional sensitivity of office-based thyroid ultrasound and its impact on clinical decision making. Surgical office-based thyroid ultrasound was performed on 49 consecutive patients who presented with thyroid disease. Indications for sonography included a solitary palpable nodule (n = 32), multiple palpable nodules (n = 3), diffuse enlargement (n = 5), or other hormonal or radiologic abnormalities (n = 9). Thyroid ultrasound demonstrated 104 lesions compared with 38 lesions found on physical examination (P < 0.0001). In the subpopulation who underwent scintigraphy (n = 10), 24 nodules were identified by ultrasound and only 10 nodules were identified by scan (P < 0.01). Overall, office-based thyroid ultrasound impacted the clinical management of 40 patients (80%): in 16 patients, thyroid ultrasound was the only modality that demonstrated a multinodular condition, thus contributing to a decision to avoid surgery; 19 patients had ultrasound-guided fine-needle aspiration of vaguely palpable or nonpalpable lesions; and 5 patients underwent ultrasound-guided cyst aspiration and follow-up. Office-based thyroid ultrasound performed by surgeons is a highly accurate imaging modality that identified significantly more lesions than physical examination or scintigraphy. Clinical management was affected through the identification of a multinodular process or through facilitation of accurate image-guided biopsy.

Distinct diagnostic criteria for ultrasonographic examination of papillary thyroid carcinoma: a multicenter study

Recent advances permitting high-resolution ultrasonography have made ultrasonographic examination of nodular thyroid diseases an accessible examination for routine practice. However, diagnostic criteria for ultrasonographic examination of thyroid nodules are not surely established. To identify the optimal strategy for well standardized differential diagnosis of papillary thyroid carcinoma and benign nodules, we evaluated the significance of individual ultrasonographic characteristics of thyroid nodules in a multicenter study. Ten characteristics in ultrasonograms from 53 patients scored by 17 investigators from 15 centers were analyzed by t tests and logistic regression analyses. Between benign and papillary thyroid cancer groups, all characteristics but not size or multiplicity of strong echoes, which suggest calcifications, were significant parameters. Logistic regression analyses showed that border character, shape, and internal echo level are highly significant parameters (p < 0.0005). A multiple logistic regression showed to be the most important predictors of pathologic diagnosis. The diagnostic criterion with border character and internal echo level yielded 93% sensitivity and 92% specificity. In conclusion, univariate and multivariate analyses identified border character, shape, internal echo level, but not strong echoes (calcifications), as important characteristics in differentiating papillary thyroid carcinoma from benign nodules. These results will contribute to standardization of accurate ultrasonographic diagnosis of papillary thyroid carcinoma.

Ultrasound in head and neck surgery: thyroid, parathyroid, and cervical lymph nodes

Ultrasound (US) of the neck is extremely sensitive in detecting thyroid, parathyroid, and cervical lymph node pathology, and is regarded as the most complete and cost-effective imaging method for evaluating the thyroid and parathyroid glands, as well as for the diagnostic evaluation of the cervical lymph node basin. US is widely used in screening high-risk individuals, evaluation of palpable and nonpalpable thyroid nodules, needle guidance for biopsy of nonpalpable and suspicious nodules, and preoperative evaluation of the extent of thyroid neoplasms, as well as in the detection of residual, recurrent, or metastatic thyroid tumors, and in observing nonsurgical cases. It has thus become an important adjunct to the practice of head and neck surgery.

Thyroid Tissue: US-guided Percutaneous Laser Thermal Ablation

PURPOSE

To evaluate in vivo the safety and effectiveness of percutaneous laser thermal ablation (LTA) in the debulking of thyroid lesions.

MATERIALS AND METHODS

Twenty-five adult patients at poor surgical risk with cold nodules (n = 8), autonomously hyperfunctioning thyroid nodules (n = 16), or anaplastic carcinoma (n = 1) underwent LTA. One to four 21-gauge spinal needles were inserted with ultrasonographic (US) guidance into the thyroid lesions. A 300-microm-diameter quartz optical fiber was advanced through the sheath of the needle. Nd:YAG laser was used with output power of 3-5 W. Side effects, complications, and clinical and hormonal changes were evaluated at the end of LTA and during follow-up. Linear regression analysis was used to investigate the correlation between energy delivered and reduction in nodule volume. Volume of induced necrosis and reduction in nodule volume were assessed with US or computed tomography.

RESULTS

LTA was performed without difficulties in 76 LTA sessions. After treatment with 5 W, two patients experienced mild dysphonia, which resolved after 48 hours and 2 months. Improvement of local compression symptoms was experienced by 12 of 14 (86%) patients. Thyroid-stimulating hormone (TSH) was detectable in five of 16 (31%) patients with hyperfunctioning nodules at 6 months after LTA. Volume of induced necrosis ranged from 0.8 to 3.9 mL per session. Anaplastic carcinoma treated with four fibers yielded 32.0 mL of necrosis. Echo structure and baseline volume did not influence response. Energy load and reduction in nodule volume were significantly correlated (r(2) =.75, P <.001). Mean nodule volume reduction at 6 months in hyperfunctioning nodules was 3.3 mL +/- 2.8 (62% +/- 21.4 [SD]) and in cold nodules was 7.7 mL +/- 7.5 (63% +/- 13.8).

CONCLUSION

LTA may be a therapeutic tool for highly selected problems in the treatment of thyroid lesions.

Ultrasound of the thyroid and parathyroid glands

Ultrasound plays a prominent role in the management of thyroid disease and parathyroid adenomas. It can detect clinically impalpable thyroid nodules and characterize them as cystic, solid, or complex. Determining that a nodule is definitively benign or malignant is difficult, and so when indicated an ultrasound-guided fine-needle aspiration can be performed. In the follow-up of patients with thyroid cancer, ultrasound can be used alone or in conjunction with computed tomography (CT)/magnetic resonance imaging (MRI) to detect recurrent disease. Recurrences can be confirmed using ultrasound to guide fine-needle aspirations. To locate parathyroid adenomas, ultrasound is often used in conjunction with sestamibi scanning. If both studies agree on the location of the adenoma, the surgeon can perform focused surgery for its removal. In patients in whom the studies do not agree or in whom they do not detect the adenoma, further evaluation with CT or more preferably MRI is indicated.

Something Old and Something New: a Brief History of Thyroid Ultrasound Technology

OBJECTIVE

To discuss both early and recent ultrasound technologic advances and to explore the role of such technology in the evaluation of the thyroid gland.

METHODS

The physics of sound and the history of the use of reflected sound waves are reviewed, and the medical applications of ultrasound, with a particular focus on the thyroid gland, are presented.

RESULTS

Since the first reports of thyroid ultrasonography were published in the late 1960s, the field has undergone remarkable evolution. Ultrasound imaging improved in parallel with growth in computing, transducer, and display technology. The transition from A-mode to B-mode to gray-scale imaging was associated with dramatic improvements in clarity and interpretability of ultrasound images. Current high-resolution ultrasound images are able to identify virtually all structural thyroid lesions of clinical significance. Although ultrasound characteristics cannot be used for accurate diagnosis of benign thyroid lesions, certain features such as irregular margins, microcalcifications, and central vascularity suggest the presence of "suspicious" thyroid nodules. Recent advances including the use of contrast agents, tissue harmonic imaging, and multiplanar reconstruction of images will further enhance the resolution and interpretability of ultrasound images. The use of Doppler flow analysis may improve the predictive value for determining the risk of a malignant thyroid lesion, but no current ultrasound technique is capable of determining benignity with an acceptable degree of accuracy. Ultrasound guidance of fine-needle aspiration biopsy has been demonstrated to improve both diagnostic yield and accuracy and will likely become the standard of care.

CONCLUSION

Because high-quality ultrasound systems are now available at a reasonable price, routine clinical use of ultrasonography is considered an important extension of the physical examination by many endocrinologists.

Slow growth of benign thyroid nodules after menopause: no need for long-term thyroxine suppressive therapy in post-menopausal women

Benign thyroid nodules represent a very common disorder, the management of which is still controversial. The aim of the present work was to evaluate by ultrasound examination the volume changes of thyroid nodules in post-menopausal women presenting single palpable nodular goiter of recent onset (less than 6 months from diagnosis). Forty-three patients received L-T4-treatment, 38 represented the no-treatment group. Long-term follow up (3 and 5 yr) did not show any significant change in the mean volume nodule in these patients. In the no-treatment group, the mean nodule volumes were stable over time from baseline to 5 yr. No significant difference was observed at any follow-up evaluation between thyroid hormone treated and untreated patients. After 1 yr of treatment, a significant decrease (p = 0.0275) in mean nodule volume occurred only for nodules with a baseline volume lower than 1.5 ml. The frequency of clinically relevant nodule size variation showed a more frequent decrease (13.9%) at 1 yr in the L-T4 group, as compared to the no-treatment group (2.6%), while the proportion of increased volume at 1 yr was higher in the untreated than in the L-T4 group (5.3% vs 2.3%). This inverse relationship between the 2 groups was not statistically significant (p = 0.076). In conclusion, an arrest in the growth of benign thyroid nodules occurs in the majority of women after menopause. Only a very limited number of these patients may benefit from thyroid hormone suppressive treatment.

Ultrasound-guided laser thermal ablation in the treatment of autonomous hyperfunctioning thyroid nodules and compressive nontoxic nodular goiter

OBJECTIVE

Percutaneous laser thermal ablation (LTA) has been applied in several tumors. In this study we evaluated the safety and long-term efficacy of LTA in the treatment of benign thyroid nodules.

DESIGN AND PATIENTS

Seven patients with autonomous hyperfunctioning thyroid nodule (group A) and five patients with compressive nodular goiter (group B) were treated with LTA. Up to three needles were positioned centrally in the thyroid nodule and laser fiber was placed in the lumen of the needle. Laser illumination was performed reaching a maximal energy deposition of 1800 J per fiber.

MEASUREMENTS

Thyroid nodule volume, endocrinologic, and clinical evaluation were performed at baseline, 3, and 12 months after the treatment. Scintigraphy was performed at diagnosis and 12 months after the first session in group A.

RESULTS

In group A, mean thyroid volume decreased from 3.15 +/- 1.26 mL to 0.83 +/- 0.49 mL (p < 0.001) after 12 months. The treatment induced disappearance of clinical signs and symptoms related to hyperthyroidism; normalization of free triiodothyronine (FT(3)), free thyroxine (FT(4)), and thyrotropin (TSH) serum levels and recovery of extranodular uptake at scintiscan. In group B, mean thyroid volume decreased from 11.14 +/- 4.99 mL to 3.73 +/- 1.47 mL (p < 0.01) after 12 months. Pressure symptoms in the neck, difficulty in swallowing and tracheal displacement improved in all patients. The treatment was well tolerated in both groups of patients.

CONCLUSIONS

LTA appears to be a valid and safe alternative approach in the treatment of benign thyroid nodules.

Causes of appearance of scintigraphic hot areas on thyroid scintigraphy analyzed with clinical features and comparative ultrasonographic findings

This study was done retrospectively to analyze the ultrasonographic (US) findings in thyroid scintigraphic hot areas (HA). Three-thousand, eight-hundred and thirty-nine consecutive patients who underwent 99mTc-pertechnetate (n = 3435) or 123I (n = 457) scintigraphy were analyzed. HA were regarded as present when the tracer concentration was greater than the remaining thyroid tissue, or when hemilobar uptake was observed. High-resolution US examinations were performed with a real-time electronic linear scanner with a 7.5 or 10 MHz transducer. One hundred and four (2.7%) were found to be scintigraphic HA (n = 120). US revealed a nodular lesion or well-demarcated thyroid tissue corresponding to the HA in 94 areas (78.4%, Category 1), an ill-defined region with different echogenicity in 13 areas (10.8%, Category 2), and no correlating lesion in 13 areas (10.8%, Category 3). These 104 patients included 43 with adenomatous goiter (59 areas), 33 with adenoma, 11 with Hashimoto's thyroiditis, 5 with primary thyroid cancer, 4 with euthyroid ophthalmic Graves' disease (EOG), 3 with hemilobar atrophy or hypogenesis, 2 with hemilobar agenesis, 2 with hypothyroidism with blocking-type TSH-receptor antibodies (TSHRAb), I with acute suppurative thyroiditis. Among the 59 adenomatous nodules and 33 adenomas, 51 (86.4%) and 32 (97.0%), respectively, belonged to Category 1. A solitary toxic nodule was significantly larger and occurs more often in older patients than in younger patients. On the other hand, all 17 patients with known autoimmune thyroid diseases including Hashimoto's thyroiditis, EOG and hypothyroidism with blocking TSHRAb belonged to Category 2 or 3. Possible underlying mechanisms are 1) hyperfunctioning tumors or nodules, 2) localized functioning thyroid tissue freed from autoimmune destruction, inflammation or tumor invasion, 3) congenital abnormality, 4) clusters of hyperactive follicular cells caused by long-term TSH and/or TSHRAb stimulation, 5) asymmetry, etc. Scintigraphic HA are observed in patients with various thyroid diseases and high-resolution US appears to be helpful clinically for the differential diagnosis of the above mentioned disorders.

Non-palpable thyroid nodules in a borderline iodine-sufficient area: detection by ultrasonography and follow-up

Thyroid ultrasonography was performed in 482 subjects, free of known thyroid disease and living in a borderline iodine-sufficient urban area, to assess the prevalence of non-palpable thyroid nodules and evaluation their evolute during a 3-yr follow-up. The mean (+/-SD) thyroid volume in the whole study group was 10.9+/-3.7 ml and was higher in males (12.9+/-3.6 ml) than in females (9.2+/-2.9 ml) (p<0.0001). Thyroid volume was correlated with body surface, height and weight, while no correlation was present with lean and fat body mass. Goiter was found in 5/256 females and in 13/226 males. Thyroid nodules were found in 27/482 subjects (18 females, 9 males). Single nodules were found in 17/464 subjects (3.66%) with a thyroid gland of normal volume and in 4/18 subjects (22.2%) with goiter (chi2=10.21; p=0.001). Multiple nodules were found in 3/464 subjects (0.6%) with a thyroid of normal volume and in 3/18 (16.6%) subjects with goiter (chi2=24.31; p<0.0001). The prevalence of thyroid nodules was significantly higher in females >35 yr than in those <34 yr (chi2=7.47; p=0.0062). A significant increase (>30%) of nodular volume was found in 5 subjects, while an increased number of nodules was found in 8. In conclusion, thyroid ultrasonography reveals the presence of thyroid nodules in a significant proportion of apparently thyroid disease-free subjects living in a borderline iodine-sufficient urban area. Incidentally discovered thyroid nodules are associated with goiter and are likely to progress in volume and number.

Fine-needle aspiration biopsy of the thyroid

The routine use of thyroid FNAB caused profound changes in the management of thyroid nodules. FNAB allows a prompt identification and treatment of thyroid malignancies and avoids unnecessary surgery in patients with benign lesions, improving quality of life in patients with thyroid nodules. Furthermore, FNAB provides guidance for the type of surgery and reduces costs of care. On average, standard FNAB is nondiagnostic in 25% to 40% of cases, which include inadequate specimens and indeterminate (suspicious) diagnoses. In addition, a small percentage of false-negative diagnoses occur, which are unavoidable and raise concern of a late diagnosis of cancer. To minimize the limitations of FNAB, every center should reach and maintain a high standard of expertise in all of the steps of smear preparation and interpretation. Alternative modes of sampling or sample preparation may result in a reduction of nondiagnostic samples and better accuracy. Every center should set up clinical guidelines tailored to their own FNAB results and including the evaluation of clinical data. More work is needed to increase the accuracy of FNAB in suspicious cases. Toward this goal a variety of molecular markers have been evaluated; although none of them are ideal, some are promising. More studies need to be carried out in larger series to further evaluate the accuracy of these markers in identifying specific cancer histotypes within the group of suspicious lesions. It is hoped that, in the near future, the routine use of a combination of these markers will cost-effectively improve the diagnosis of malignant nodules classified as suspicious on traditional cytology. Statistical methods such as bayesian analysis or neural networks can be advantageously used to integrate different relevant information derived from family and personal history, clinical data, cytologic results, and evaluation of molecular markers.

Thyroid incidentalomas. Prevalence, diagnosis, significance, and management

Thyroid incidentalomas are common, always impalpable, often less than 1.5 cm in size, and frequently benign. The authors recommend that low-risk patients with incidentalomas be followed up with clinical palpation in 6 to 12 months and not be subjected to routine testing with US-FNA. In the authors' strategy, fine-needle aspiration is reserved for an impalpable nodule and is performed under ultrasonographic guidance in the high-risk group of patients in whom either the imaging features or the clinical history is worrisome for malignancy. It does not seem necessary, practical, or cost-effective to perform biopsy or to excise surgically all impalpable nodules. Because of the high prevalence of thyroid incidentalomas, most of which are benign, a nonsurgical approach is logical.

Imaging the thyroid

Thyroid imaging has historically relied heavily on scintigraphy, although, not surprisingly in view of the superficial position of the gland, ultrasound has assumed an increasingly prominent role in recent years. The other cross-sectional imaging modalities can also be useful, and the emergence of new radiopharmaceuticals and the increasingly central role of fine needle aspiration cytology have further added to the range of diagnostic techniques available. This review attempts to summarize the current state of knowledge, and makes some suggestions for the most efficient use of imaging resources in the investigation of thyroid disease.

The role of ultrasound in the diagnosis of a large, rapidly growing, thyroid mass

The value of ultrasound in the diagnosis of a large rapidly growing thyroid mass was assessed in a study of 42 patients with a large (> 3 cm) rapidly growing (< two months) solitary mass. Haemorrhage into a thyroid nodule was present in 31 patients and thyroid malignancy in 11. Ultrasound of haemorrhage into a thyroid nodule revealed a large cystic mass in all 31 patients containing internal debris (22), septations (three), or a combination of both (six). The malignant causes of a large rapidly growing mass were lymphoma (two), anaplastic carcinoma (four) and metastasis (five). Ultrasound of these thyroid malignancies revealed a mass with a smooth, well-defined margin and strikingly low homogeneous echogenicity in all cases. Patients with thyroid metastases had evidence of widespread metastatic disease elsewhere. Lymphoma was differentiated from anaplastic carcinoma on fine-needle aspiration cytology or surgical biopsy. Ultrasound was of value in differentiating between a benign haemorrhagic nodule and a malignant tumour. The various malignant tumours had similar appearances, however, and could not be distinguished on ultrasound.

Thyroid Ultrasonography—A Review

OBJECTIVE

To review the major applications of ultrasonography in studies of the thyroid gland by clinical endocrinologists.

METHODS

The techniques for performance of thyroid ultrasonography and ultrasound-guided fine-needle aspiration biopsy are outlined, and the settings for their use are discussed. Characteristic findings and limitations are described.

RESULTS

In two situations--the assessment of thyroid nodules and the postoperative follow-up of thyroid cancer--ultrasonography and ultrasound-guided fine-needle aspiration biopsy have proved to be clinically useful when used in combination. On ultrasonography, a hyperechoic nodule with a sharp "halo" is associated with a low risk of malignancy and a hypoechoic nodule with microcalcifications is associated with a high risk of a malignant lesion, but performance of a biopsy is recommended. Ultrasonography coupled with ultrasound-guided fine-needle aspiration biopsy can detect >90% of recurrent cases of thyroid carcinoma. In general, normal lymph nodes appear flattened on ultrasonography, whereas malignant nodes appear more rounded or bulging.

CONCLUSION

Thyroid ultrasonography and fine-needle aspiration biopsy are complementary diagnostic procedures in the evaluation of thyroid nodules and for detection of recurrent or metastatic thyroid carcinoma.

The role of thyroid fine needle aspiration (FNA) cytology in a District General Hospital setting

The pilot study was undertaken to evaluate the role of FNA cytology in the clinical management of patients with thyroid swelling, in a District General Hospital (DGH) setting. One hundred and eleven patients were investigated over a period of 3 years, with a total of 142 fine needle aspirations. Statistical analysis showed a sensitivity of 71%, a specificity of 91% and a false negative rate of 2.7%. These results compare very favourably with other institutions. This study therefore shows that thyroid nodule FNA cytology can be performed in a DGH with a high standard of diagnostic accuracy, the results of which play a key role in patient management.

Advances in the management of patients with thyroid disease

Discoveries related to thyroid immunology, especially concerning the thyroid-stimulating hormone (TSH) receptor, may facilitate new immunologic approaches to the therapy of Graves' disease and the thyroiditis syndromes. Advances in genetics are being applied to the thyroid hormone resistance syndromes and papillary and medullary carcinomas. The development of ever more sensitive TSH assays has led to the detection of subclinical thyroid disease, which has special implications for the sick and elderly patients. Sensitive TSH assays also allow more precise titration of levothyroxine (T4) dosages, especially for patients with a past history of thyroid cancer. Evidence continues to accumulate suggesting that postmenopausal women on T4 doses that suppress the TSH level below 0.1 ulU/mL have lower bone mineral density than matched patients with healthy TSH levels. Also, pregnant hypothyroid women need higher T4 doses to normalize the TSH levels. In the evaluation of thyroid nodules, fine-needle aspiration biopsy is the single most definitive modality in selecting the patients for surgery. Scintigraphy provides a complimentary role, especially in defining autonomously functioning thyroid adenomas (AFTA), because these should not be treated with T4 suppression. Ultrasound-guided needle biopsy is occasionally helpful with nodules that are difficult to palpate. Concern for possible tracheal compression after treatment of toxic multinodular goiter with large doses of radioactive iodine (I-131) in the range of 50 to 150 mCi (1.85 to 5.5 GBq) does not seem warranted. Work, primarily out of Italy, suggests AFTA can be ablated with repeat ethanol injections. Residual tissues after thyroidectomy for differentiated carcinoma can be "stunned" by tracer doses of 131I greater than 3.0 mCi (111 MBq), which diminishes the uptake and effectiveness of a subsequent therapy dose. Positron emission tomograph, imaging with thallium-201, and Technetium 99m Sestamibi can identify a small number of patients shown to have metastases from differentiated thyroid carcinoma by increasing thyroglobulin levels in the absence of 131I uptake. Several groups have recently advocated treating such patients empirically with 131I.

Evidence for the effect of antibodies to TSH receptors on the thyroid ultrasonographic volume in patients with Graves' disease

OBJECTIVE

It has been demonstrated that antibodies (Ab) to thyroid-stimulating hormone receptors (R), which stimulate the thyroid gland, induce hyperthyroidism in patients with Graves' disease. Furthermore, it has been shown in thyroid cells in culture that thyroid-stimulating hormone receptor Ab acts through the adenosine 3', 5'-monophosphate pathway which stimulates both thyroid hormonogenesis and growth. We investigated the relations between thyroid autoimmunity expression and thyroid ultrasonographic parameters or thyroid hormonal status in patients with Graves' disease.

PATIENTS

A prospective study of 53 consecutive patients referred with untreated Graves' disease.

MEASUREMENTS

Measurements were made of serum TSH-R, peroxidase (TPO) and thyroglobulin (Tg) Ab and basal plasma free T4 (FT4), free T3 (FT3) and TSH. Thyroid morphological characteristics (number and total volume of nodule(s), total volume of lobes and total thyroid volume) were determined by ultrasonography.

RESULTS

There were significant correlations (P < 0.001) between TSH-RAb levels and FT4 values (r = 0.48) or FT3 levels (r = 0.46). Likewise, significant correlations were found between TSH-RAb levels and total lobe volume values (r = 0.56, P < 0.001), total nodular volume values (r = 0.59, P < 0.01) or total thyroid volume values (r = 0.63, P < 0.001). By contrast, no correlation was found between TSH-RAb levels and the number of nodules or between any of the ultrasonographic parameters and TPOAb levels or TgAB values.

CONCLUSIONS

This study demonstrates, in vivo, that TSH receptor antibodies modulate the thyroid ultrasonographic extranodular and nodular volumes in patients with Graves' disease.

Consumption of drinking water with high nitrate levels causes hypertrophy of the thyroid

We studied the effect of nitrate contamination of drinking water on volume and function of the thyroid in human populations exposed to different nitrate levels in their drinking water. Two sets of low and medium (tap) water, respectively medium and high (well) water nitrate exposure groups were compared. Drinking of nitrate-contaminated water was dose-dependently related with 24-h urinary nitrate excretion and salivary nitrate levels. No iodine deficiency was observed in any of the nitrate exposure groups. A dose-dependent difference in the volume of the thyroid was observed between low and medium vs. high nitrate exposure groups, showing development of hypertrophy at nitrate levels exceeding 50 mg/l. An inverse relationship was established between the volume of the thyroid and serum thyroid stimulating hormone (TSH) levels.

Amyloidosis of the thyroid gland: role of ultrasonography

We studied the role of ultrasound assessment of the thyroid gland in detecting amyloid deposition in 9 patients confirmed to have renal amyloidosis because the thyroid gland is a readily accessible organ. Ultrasound examination of the thyroid gland showed a distinctive abnormal appearance in 7 patients. There was enlargement of one or both lobes of the thyroid, a high echogenicity approaching that of the surrounding connective tissue, and a very fine homogeneous echotexture similar to ground glass appearance. Four patients showed dilated follicles in the thyroid gland. The other two patients had normal ultrasound findings. Open wedge biopsy of the thyroid gland in 4 patients, (3 with abnormal ultrasound findings and 1 with normal ultrasound findings) showed amyloid deposits in the 3 patients with abnormal echo findings and no amyloid deposits in the 1 patient with normal findings. In 10 healthy individuals, 10 patients who were just initiated on maintenance hemodialysis and another 10 patients on dialysis for more than 1 year, the thyroid gland was of normal size and appearance in the ultrasound examination. We conclude that ultrasound examination by an experienced radiologist is a useful tool in the diagnosis of thyroid amyloidosis.

Ultrasonic evaluation of benign and malignant nodules in echographically multinodular thyroids

In 165 patients with ultrasound findings of multinodular thyroids in whom thyroid resection was performed, sonographic features and pathohistologic findings of removed nodules were analyzed. Of 426 nodules removed, 70 were carcinomas and 356 benign. Carcinomas are more often hypoechogenic (p < 0.01) and contain nodular calcifications (p < 0.01), while benign nodules are more often iso-hyperechogenic (p < 0.01), showing intranodular cystic degenerative changes (p < 0.01) and perinodular hypoechogenic rim (p < 0.01). Mean diameter of carcinomatous nodules is lower than in benign nodules (p = 0.022). The relative proportion of malignant nodules is highest in the upper halves of thyroid lobes (p < 0.01). Although certain sonographic signs increase the likelihood of a given lesion being malignant or benign, the lack of absolute specificity in the ultrasound evaluation of thyroid nodules was confirmed.

Differential movement during swallowing as an aid in the detection of thyroid pseudonodules

The clinical examination of neck masses is clearly imperfect and false-positive detection of thyroid nodules, termed "pseudonodules," remains a common problem. Movement on swallowing has been emphasized as a highly specific feature of thyroid masses, but lesions in the vicinity of the thyroid can be displaced by underlying structures during deglutition, causing them to mimic thyroid nodules. Two cases are presented to illustrate how additional features of neck mass movement can help determine whether a lesion is located within the thyroid or whether it is extrathyroidal. These include the range of motion of the mass, the presence or absence of a stationary phase prior to descent, and the timing of the movements of the mass. Assessment of these parameters during the physical examination of anterior neck masses may help reduce the incidence of thyroid pseudonodules.

Prevalence of subclinical hyperthyroidism and relationship between thyroid hormonal status and thyroid ultrasonographic parameters in patients with non-toxic nodular goitre

OBJECTIVE

Basal plasma T4, T3 and TSH concentrations are usually normal in patients presenting with non-toxic nodular goitre. Using the evaluation of TSH response to TRH in a large series of such patients living in an area with normal iodine intake, we evaluated the prevalence of subclinical hyperthyroidism and the relationship between thyroid hormonal status and ultrasonographic parameters.

PATIENTS

A prospective study of 242 consecutive patients (group I), referred with non-autoimmune nodular goitre, normal plasma free T4, total T3 and TSH levels, without (subgroup IA, 222 patients) or with (subgroup IB, 20 patients) clear-cut autonomous area(s) on scintigraphy. These patients were compared to 135 controls (group II).

MEASUREMENTS

Plasma free T4 (FT4), total T3 (T3T) and TSH measurements. Evaluation of TSH response to TRH (delta level of increased TSH = peak TSH level during TRH test-basal TSH level), thyroid scintigraphy and morphological characteristics (number and total volume of nodule(s) and volume of extranodular tissue) determined by ultrasonography.

RESULTS

In subgroup IA, (1) the mean (+/- SEM) basal TSH level (0.94 +/- 0.04 mU/I) and the mean value of increased TSH after TRH (4.92 +/- 0.34 mU/I) were lower (P < 0.001) than in group II (1.28 +/- 0.05 mU/I and 7.24 +/- 0.25 mU/I, respectively). The prevalence of SH (delta level of increased TSH below the mean -3 SD in controls) was 17.2%; (2) the mean FT4 level and the mean T3T value were not different (P > 0.05) from those of group II. In subgroup IB, (1) the mean basal TSH level (0.57 +/- 0.11 mU/I) and the mean increment of TSH after TRH (2.81 +/- 0.62 mU/I) were lower (P < 0.001) than in subgroup IA. The prevalence of subclinical hyperthyroidism was 75.0%; (2) the mean FT4 level (17.2 +/- 0.9 pmol/I) was not different from that in group II. However, the mean T3T value (1.99 +/- 0.01 nmol/I) was higher (P < 0.001) than in group II (1.65 +/- 0.05). In group I, subgroup IA and IB, there were significant (P < 0.05, at least) correlations between the numbers of nodules and both basal TSH levels and delta values of increased TSH or FT4 levels or T3T values. No correlations were found between other ultrasonographic data and plasma thyroid parameters.

CONCLUSIONS

This study demonstrates a high prevalence of subclinical hyperthyroidism in patients presenting with non-toxic nodular goitres and suggests that the number of nodules, but not their total volume, is an important factor in the development of this condition.

Ultrasonography of the thyroid gland in pregnancies complicated by autoimmune thyroid disease

Thyroid function and ultrasonographically determined thyroid volume were studied in nine pregnant women with diagnosed autoimmune thyroid disease at regular intervals during pregnancy and two months after delivery. The results were compared to the findings in ten healthy pregnant women. In ultrasound examinations seven of the patients showed definite morphological changes such as hypoechogeneity and inhomogeneity of the thyroid gland, which did not change during the course of pregnancy nor during the post-partum period of eight weeks. There were no morphological changes in the thyroid glands of the control group. The mean thyroid volume did not significantly change during pregnancy and after delivery in both the patient group and controls. The mean thyroid volume was smaller in the study group, with 7.55 ml (SD 6.01) compared to the controls with 11.29 ml (SD 5.61), a difference which was not statistically significant. Neither course of pregnancy nor fetal outcome was influenced by inactive autoimmune disease of the thyroid.

Sonography in thyroid carcinoma in children

This paper reviews the clinical, sonographic and pathological findings of 20 children with thyroid carcinoma in an attempt to determine the value and limitations of sonography in thyroid neoplasms in this age group. Although sonography is an excellent technique for the evaluation of thyroid disorders and masses, certain limitations must be kept in mind. Microscopic foci of tumour might be missed and sonography cannot predictably differentiate benign from malignant disease. Previous radiation exposure should increase the level of suspicion for malignancy.

Suppressive therapy with levothyroxine for solitary thyroid nodules

OBJECTIVE

To evaluate the effect of treatment with TSH suppressive dose of levothyroxine in patients with benign thyroid nodules.

DESIGN

Prospective randomized study. Group A (n = 20) patients received levothyroxine and group B (n = 20) patients did not. The dose of levothyroxine was adjusted to obtain an effective suppression of TSH. A clinical, analytical and morphological (with ultrasound) review was performed every 3 months. The mean +/- SD follow-up period was 10.6 +/- 2.2 months.

PATIENTS

Forty euthyroid women with solitary thyroid nodule on palpation, cold on scintigraphy and cytologically benign without contraindication participated.

MEASUREMENTS

At entry: biochemical and hormonal parameters, thyroid scintigraphy and thyroid ultrasonography. Every 3 months additional determinations of thyroid hormones and TSH levels were carried out, if necessary, to verify effective TSH suppression. Every 6 months thyroid ultrasound imaging was performed.

RESULTS

Patients were euthyroid at entry into the study. The mean dose of levothyroxine necessary to obtain TSH suppression was 2.82 +/- 0.6 micrograms/kg/day. No significant modification in the thyroid nodule diameter (mean +/- SD 2.6 +/- 1.2 vs 2.5 +/- 1.2 cm) or in the thyroid nodule volume (10.3 +/- 11.9 vs 10.1 +/- 12.2 ml) were observed in group A. In group B the results were similar (2.8 +/- 0.9 vs 2.7 +/- 1.8 cm and 9.2 +/- 6.4 vs 9.2 +/- 9.5 ml, respectively). No differences were found in either group in the number of nodules that reduced significantly their volume (four and three, respectively).

CONCLUSIONS

The suppressive therapy with levothyroxine was not effective in reducing nodule sizes in patients with solitary benign thyroid nodules.

Thyroid hormone suppressive therapy of sporadic nontoxic goiter

Thyroid hormone has been used to reduce the size of sporadic nontoxic goiter since 1894. Noncontrolled clinical studies suggest that about two thirds of goiters respond to therapy, and a recent randomized clinical trial confirms the efficacy of suppressive therapy for sporadic nontoxic goiter. Efficacy is at least partly correlated with suppression of pituitary TSH production, response is usually evident by 3 months, relapse occurs when therapy is withdrawn, and nodular goiters may be less responsive than diffuse goiters. Some, but not all, series suggest that postoperative use of thyroid hormone suppressive therapy prevents recurrence of benign goiter. Three recent randomized trials suggest that thyroid hormone administered for 6 months to 3 years does not reduce the size of solitary thyroid nodules. About one third of nodules regressed in both treatment and placebo groups. Long-term studies are needed to define the effects of thyroid hormone suppressive therapy on the growth of goitrous lesions based on their underlying pathophysiology.

Acute fungal thyroiditis in a patient with acute myelogenous leukaemia

Acute suppurative thyroiditis of any origin is uncommon, but fungal infections of the gland are particularly rare. Haematogenous spread is the usual route of infection. We here present the case of a recently encountered patient with neutropenic fever and Candida thyroiditis. Fine-needle aspiration biopsy greatly aided the diagnosis. In immunocompromised patients, the specimens should be treated with special stains to detect the presence of opportunistic organisms; if any are found, appropriate therapy should be initiated.

Diagnostic dilemma. The goiter

The incidence of goiters in children is about 4% to 5%. The first step in the evaluation is to decide whether the swelling indeed involves the thyroid. After careful examination, one determines if the thyroid is diffusely or focally enlarged. A solitary nodule merits an extensive workup because of the high rate of malignancy. The evaluation of a diffuse goiter proceeds after deciding if the patient is euthyroid, hypothyroid, or hyperthyroid. In most cases, the child is euthyroid and the diagnosis is either CLT or simple colloid goiter. Laboratory tests for thyroid function and antibodies usually make the diagnosis. The hypothyroid patient most likely has CLT, although drugs or goitrogens, dyshormonogenesis, and thyroid resistance are also possible. The hyperthyroid patient usually has Graves' disease. The incidence of malignancy of solitary thyroid nodules is 15% to 40%; therefore, evaluation must be sensitive enough not to miss cancer. Ultrasonography helps to delineate the anatomy and to reveal if the nodule is cystic. Radionuclide scans are useful, as warm or hot lesions are rarely malignant. Cold nodules require further investigation, and in most institutions, this amounts to open biopsy. Fine-needle aspiration may be used if the clinician and pathologist are experienced. With this aggressive approach to thyroid nodules, malignancies are given early treatment. The prognosis is good in most thyroid carcinomas.

Cystic papillary carcinoma of the thyroid gland: a new sonographic sign

Cystic thyroid lesions are generally considered to be benign and managed by repeated aspiration and/or biopsy. We report characteristic sonographic signs in eight cases of cystic papillary carcinomas of the thyroid gland. In all eight cases, ultrasonography (US) revealed mostly cystic lesions with solid excrescences protruding into the cyst. These nodules contained multiple punctate echogenic foci suggesting calcification. In three of these cases the initial fine needle aspiration biopsy was negative. The 'calcified nodule in cyst' sign was found to be very specific for cystic thyroid carcinoma in a review of the ultrasound findings in 115 patients with nodular thyroid lesions. Careful evaluation and/or surgery should be recommended in patients who have such characteristic sonographic findings even if the fine needle aspiration result is negative.

Sonographic diagnosis and grading of Hashimoto's thyroiditis

There is no ideal test for the diagnosis of Hashimoto's thyroiditis (HT). The purpose of this study was to determine the type of information sonography provides in these patients. In 47 cases of HT we identified four distinct sonographic patterns which correlated with degree of disease severity. The higher patterns had larger glands, higher antithyroid antibody titers, lower T4 and higher TSH levels, and higher incidence of hypothyroidism. With sonography we were able to suspect the diagnosis in patients with goiter of unknown etiology, to measure gland size, identify patients with functional impairment, and predict which patients required treatment. No other single test provides so much information in patients with HT.

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

The aim of this study was to assess prospectively the value of thyroid nuclear scans and ultrasound examination in the preoperative investigation of patients with a solitary thyroid nodule. Total thyroid lobectomy for a solitary thyroid nodule was performed in 68 cases. Each patient had a thyroid isotope scan (except two women who were pregnant) and thyroid ultrasound examination. There were 10 (15 per cent) malignant nodules, 11 (16 per cent) benign neoplastic nodules and 47 (69 per cent) benign non-neoplastic nodules. All of the patients with malignant nodules who were scanned had a solitary cold nodule on thyroid scan, as did 40 (69 per cent) of those with benign solitary nodules. Ultrasound examination of the thyroid suggested correctly that one of 16 (6 per cent) cystic lesions, four of 16 (25 per cent) complex solid-cystic lesions and three of 18 (17 per cent) of solid lesions were malignant. One lesion reported as multinodular on ultrasonography and one reported as normal also turned out to be malignant. Thyroid isotope scans and ultrasound do not accurately differentiate between benign and malignant conditions and their routine use in the investigation of a solitary thyroid nodule should be abandoned.

Ultrasound appearances of de Quervain's thyroiditis

De Quervain's thyroiditis can be readily recognised by ultrasound. The sonographic features and previously unreported signs of two such cases are illustrated. One case had typical multiple hypoechogenic areas in the thyroid parenchyma. The other had multiple small areas giving a spotty appearance not previously reported in de Quervain's. Both patients demonstrated remarkable shrinkage of the gland (to 17.4% and 57% of the original presenting volume). We believe this is a useful diagnostic feature of de Quervain's thyroiditis.

Management of thyroid nodules

This review describes the frequency of solitary thyroid nodules and their relationship to thyroid cancer. The importance of selecting patients appropriately for surgical excision is stressed. The factors predisposing to nodule formation and to a nodule being malignant are reviewed with emphasis that prior radiation exposure does not appear to increase the likelihood that a given nodule harbors a malignancy. In considering the laboratory evaluation of thyroid nodules, the limitations of isotope scans and ultrasonography are noted. Fine needle aspiration biopsy is described as revolutionizing the management of thyroid nodules and decreasing unnecessary operations. In the context of the natural history of differentiated thyroid cancer, the application of a decision analysis model to management options is described in some detail, and a cost-effective management regimen is recommended with fine needle aspiration biopsy as the initial procedure.

Solitary thyroid nodule: diagnosis and management

Thyroid nodules are common. Most are benign lesions since clinically important thyroid carcinoma is a relatively rare disease. The most sensitive and specific test for the diagnosis of thyroid cancer is fine-needle aspiration biopsy, but its diagnostic accuracy depends upon whether or not one excises all suspicious nodules, thus including them as correctly diagnosed. Nevertheless, fine-needle aspiration biopsy is the most sensitive, specific, and cost-effective test for thyroid cancer. Therapy depends upon the cause of the thyroid nodule.

Thyroid nodules and thyroid cancer--diagnostic aspects

The clinical evaluation of patients with thyroid nodules is a common problem confronting the clinician. The vast majority of such nodules are benign, but concern that such a thyroid swelling may harbour malignancy demands prompt and accurate diagnosis. Furthermore, it is clear that properly treated differentiated thyroid carcinoma is associated with an excellent prognosis. The objective of investigating patients presenting with thyroid nodules is to define the small number of malignancies with minimum inconvenience to the patient in the most cost-effective way. There are no laboratory tests which reliably differentiate benign from malignant disease. The traditional approaches of radionuclide and ultrasound scanning have been shown to be poorly specific in the diagnosis of malignancy, resulting in many unnecessary operations for benign lesions. These tests have been replaced in many centres by fine needle aspiration cytology, with surgery for abnormal cytological findings alone. This technique is easily performed in an out-patient clinic and is well tolerated; accuracy in the diagnosis of thyroid neoplasia of up to 97% can be achieved.

Ultrasonographic study of the relation of metastatic nodes to the carotid artery

Ultrasonographic studies of the neck were performed in four patients with metastatic lymph nodes that exhibited limited mobility or fixation to the surrounding tissues on palpation to obtain information about the relationship of nodes to the carotid artery. Comparison of the ultrasonograms with the operative findings disclosed that when a metastatic lymph node adhered to the carotid artery, the lymph node pulsated with flattening of the carotid artery and the echoes between the metastatic lymph node and carotid artery were attenuated.