Nonpalpable Thyroid Nodules Research Articles

Impact of Thyroid Incidentaloma on Liver Transplant: A Study of 1010 Recipients at a Single Center.

BackgroundThyroid incidentalomas are typically nonpalpable thyroid nodules discovered during radiographic evaluation for a non-thyroid issue. Thyroid incidentalomas visualized by computed tomography (CT) and 18F-flurodeoxyglucose (FDG) positron emission tomography (PET) before living donor liver transplantation (LDLT) are rare. The aim of the study was to analyze the clinical impact of thyroid incidentalomas discovered prior to transplantation.Material/MethodsThis retrospective study recruited 1010 patients undergoing LDLT between 2010 and 2019. CT was performed on each patient, whereas PET was performed on randomized patients (n=498).ResultsThe prevalence and malignant risk of thyroid incidentaloma on CT was 2.3% (23/1010) and 13.0% (3/23), respectively. The prevalence of thyroid incidentaloma on PET was 3.0% (15/498). Approximately half of the FDG uptake on PET was diffuse uptake (n=7), whereas the other half was focal uptake (n=8). The malignant risk of PET incidentaloma with focal FDG uptake was 37.5% (3/8). Four asymptomatic thyroid cancers were identified incidentally. After total thyroidectomy followed by LDLT, these patients maintained cancer-free status.ConclusionsThyroid incidentalomas occurred at a rate of 2–3% in LDLT candidates. The malignant risk was 13.0% on CT incidentaloma, and 37.5% on PET incidentaloma with focal FDG uptake. Curative treatment of incidental thyroid cancer followed by LDLT without delay can achieve a favorable prognosis.

The Value of Ultrasound in Classification of Thyroid Hypoechoic Nodules

This study evaluates the value of ultrasound in classifying hypoechoic nodules of thyroid of 70 patients at the Department of Diagnostic Imaging and Oncology of E Hospital from January 2019 to December 2019. The study results show that the patients’ average age was 55.29 ± 13.7; the female/male ratio was approximately 6.5/1; patients with a history of radiotherapy to the neck area and chronic thyroid disease had a very high risk of developing cancer; homogeneous hypoechoic nodules had a higher risk of malignancy than the heterogeneous; the sign of height ≥ width had the diagnostic value of thyroid malignant nodule with Se = 57.8%, Sp = 89.6%, PPV = 88%, NPV = 89.6%, Acc = 41.4%, OR = 10.03; the sign of border irregularity had the diagnostic value of thyroid malignant nodule with Se = 77.8%, Sp = 80%, PPV = 87.5%, NPV = 66.7%, Acc = 57.1%, OR = 14; microcalcification has a diagnostic value of thyroid malignant nodule with Se = 71.1%, Sp = 56%, PPV = 17.4%, NPV = 51.9%, Acc = 57.1%, OR = 3.1. TIRADS 4B, 5 actually had a higher risk of malignancy than TIRADS 4A. The study concludes that ultrasound has a great value in orienting malignant lesions of hypoechonic thyroid nodules.
 Keywords: Thyroid nodule, thyroid hypoechoic nodule, TIRADS.
 References
 [1] F. Bray, J. Ferrlay, I. Soerjomataram et al., Global Cancer statistics 2018: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries, CA: A Cancer Journal for Clinicians, Vol. 68, No. 6, 2018, pp. 394-424. https://doi.org/full/10.3322/caac.21492.[2] E. Papini, R. Guglielmi, A. Bianchini, A. Crescenzi et al., Risk of Malignancy in Nonpalpable Thyroid Nodules: Predictive Value of Ultrasound and Color-Doppler Features, The Journal of Clinical Endocrinology & Metabolism, Vol. 87, No. 5, 2002, pp. 1941-1946, https://doi.org/10.1210/jcem.87.5.8504.[3] T. T. Hong, Image Characteristics and Value of Ultrasound in the Diagnosis of Localized Thyroid Lesions, Master of Medicine Thesis Majoring in Diagnostic Imaging of Hanoi Medical University, 2013 (in Vietnamese).[4] V. T. Giao, Research on Ultrasound Values in TIRADS Classification of Localized Thyroid Lesions, Master of Medicine Thesis Majoring in Diagnostic Imaging, Hanoi Medical University, 2015 (in Vietnamese).[5] B. Y. Cho, H. S. Choi, Y. J. Park, J. A. Lim, H. Y. Ahn et al., Changes in the Clinicopathological Characteristics and Outcomes of Thyroid Cancer in Korea Over the Past Four Decades, Thyroid, Vol. 23, No. 7, 2013, pp. 797-804, https://doi.org/10.1089/thy.2012.0329.[6] C. M. Oh, S. Park, J. Y. Lee et al., Increased Prevalence of Chronic Lymphocytic Thyroiditis in Korean Patients With Papillary Thyroid Cancer, PLoS One, Vol. 9, No. 6, 2014, pp. 1-7, https://doi.org/10.1371/journal.pone.0099054.[7] G. Grani, L. Lamartina, V. Ramundo, R. Falcone, et al., Taller-Than-Wide Shape: A New Definition Improves the Specificity of TIRADS Systems, Eur Thyroid J, Vol. 9, No. 2, 2020, pp. 85-91, https://doi.org/10.1159/000504219.[8] B. Moifo, E. O. Takoeta, J. Tambe et al., Reliability of Thyroid Imaging Reporting and Data System (TIRADS) Classification in Differentiating Benign from Malignant Thyroid Nodules, Open Journal of Radiology, Vol. 3 No. 3, 2013, pp. 103-107, http://dx.doi.org/10.4236/ojrad.2013.33016.[9] H. J. Moon, J. Y. Kwak, M. J. Kim et al, Can Vascularity at Power Doppler US Help Predict Thyroid Malignancy?, Radiology, Vol. 255, 2010, pp. 260-269, https://doi.org/10.1148/radiol.09091284.[10] E. Horvath, S. Majlis, R. Rossi et al., An Ultrasonogram Reporting System for Thyroid Nodules Stratifying Cancer Risk for Clinical Management, J Clin Endocrinol Metab, Vol. 94 No. 5, 2009, pp. 1748-1751, https://doi.org/10.1210/jc.2008-1724.[11] G. Russ, B. Royer, C. Bigorgne et al., Prospective Evaluation of Thyroid Imaging Reporting and Data System on 4550 Nodules With and Without Elastography, Eur J Endocrinol, Vol. 168, No. 5, 2013, pp. 649-655, https://doi.org/10.1530/EJE-12-0936.[12] J. H. Shin, J. H. Baek, J. Chung et al., Ultrasonography Diagnosis and Imaging-Based Management of Thyroid Nodules: Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations, Korean J. Radiol., Vol. 17, No. 3, 2016, pp. 370-395, https://dx.doi.org/10.3348%2Fkjr.2016.17.3.370.[13] F. N. Tessler, W. D. Middlenton, E. G. Grant et al., ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee, J Am Coll Radiol., Vol. 14, No. 5, 2017, pp. 587-595, https://doi.org/10.1016/j.jacr.2017.01.046.[14] N. T. T. Thao, N. L. Lam, V. D. Luu, Research Into the Value in the Diagnosis of Thyroid Cancer of the EU-TIRADS 2017 Classification, Vietnamese Journal of Radiology, No 33, 2019, pp. 12-18, https://radiology.com.vn/bao-cao-khoa-hoc/nghien-cuu-gia-tri-chan-doan-ung-thu-tuyen-giap-cua-phan-do-eu-tirads-2017-n125.html/, (accessed on: Deceber 4th, 2019) (in Vietnamese).

Clinicopathological evaluation of thyroid incidentaloma: a prospective study

Background: Incidental thyroid nodules are typically non-palpable thyroid nodules found during radiographic evaluation for a non-thyroid related issue (USG neck, CT scan, PET scan, carotid duplex).The prevalence of thyroid incidentalomas ranges from 1.6% to 67% based on radiographic modality of detection. The rate of malignancy in incidental thyroid nodule can again quite variable based on how it was discovered and range from 4% to 50%. (The overall risk is approximately 15%). Methods: A prospective study was carried out in 100 patients. Discovery of a thyroid nodule by imaging investigations in individuals, who are asymptomatic for thyroid disease, was done in the study. FNAC of the nodule is done to know the pathology. Results: Incidence of thyroid incidentaloma was found to be 9%. In 40 patients who underwent carotid doppler the incidence was found to be 10%. In 50 patients who underwent USG neck, the incidence was found to be 10%. There was no incidentaloma detected in CT done in the 10 patients observed in this study. 9 patients with thyroid incidentalomas out of which 7 patients diagnosed benign lesion and 2 patients diagnosed with malignancy. Conclusions: Incidence of thyroid incidentaloma in our study is comparable to worldwide statistics. The incidence of incidentaloma (9%) and malignant pathology (22.2%) picked up in incidentalomas in our study is going in favour of advocating screening programme in our population (>50 years). USG neck appears to be most suitable investigation for screening.

Nodular thyroid disease in the elderly: novel molecular approaches for the diagnosis of malignancy.

Epithelial thyroid cancers (TC) comprise two differentiated histotypes (DTC), the papillary (PTC) and the follicular (FTC) thyroid carcinomas which, following dedifferentiation, are assumed to give rise to the poorly differentiated thyroid carcinomas and the rare, but highly aggressive and invariably fatal, anaplastic thyroid carcinomas. Although thyroid cancer mortality has not been changed, its annual incidence has increased over the last two decades, mainly because of the improved ability to diagnose malignant transformation in small non-palpable thyroid nodules. Despite DTC patients have a favorable prognosis, aggressive disease is more frequently observed in the elderly showing a higher disease-specific mortality. Of relevance is the high prevalence of nodular thyroid disease in aged patients being higher than 90%, in women older than 60year, and 60% in men older than 80year. This implies a careful evaluation of thyroid nodules in this group of patients in order to exclude malignancy. In fact, despite the tremendous progress in the comprehension of the underlying molecular mechanisms deregulated in DTC progression, several aspects of their clinical management remain to be solved and novel diagnostic strategies are sorely needed. Here, we will attempt to review new molecular approaches, which are currently being exploited in order to ameliorate the diagnosis of thyroid nodules.

Clinical, imaging and cytological differences between palpable and non-palpable thyroid nodules

Clinical, imaging and cytological differences between palpable and non-palpable thyroid nodules

Role of Ultrasound in Thyroid Pathologies

This is a retrospective study of thyroid patients referred for ultrasound for the period of 2007to 2009 at different hospitals and dispensaries in the Kingdom of Saudi Arabia (Eastern area). Importance of the study is ; to create a reliable reference for the role of ultrasound in thyroid pathologies in King Saudi Arabia. Study aimed to detect the Ultrasonic Differential Diagnosis of Thyroid pathologies. This study was carried out on 303 patients of various types of thyroid diseases in King Saudi Arabia.232 (77 %) were female patients and 71(23 %) were males. Along this series there were 25 % of enlarged thyroid gland which act as the most common ultrasound findings of thyroid disorders followed by, 23 % solitary thyroid nodules, 10 % multinodular goiters, 8 % simple cyst, 7 % nonpalpable thyroid nodules, 4 % goiter and Hashimoto's thyroiditis. The most common ultrasound findings of thyroid gland enlarged of thyroid. The least common is nodal enlargement, adenoma, thyroiditis, microcalcifications, small size thyroid, multiple thyroid nodules, thyroglossal cyst and Graves disease. Out of this study we believe more that ultrasound should be the first-line test owing to its safety and availability.

Evaluation of non-palpable thyroid nodules by ultra sound guided fine needle aspiration cytology

The aim of this study was to see the usefulness of fine needle aspiration by “theBethesdasystem for reporting Thyroid Cytopathology” (TBS- RTC) for non palpable thyroid nodules through ultrasound-guidance for the evaluation and treatment planning of nonpalpable thyroid lesions. This study was conducted on 200 patients with non palpable thyroid nodules which are very low lying or felt on swallowing; in Department of Pathology and Radiology since January 2011 to June 2012. The patients were scanned and USG- FNAC was performed and reporting was done by “TBSRTC”. Of the 200 specimens 17 samples were nondiagnostic or unsatisfactory (Class I), 145 samples were benign (Class II), 20 samples were showing Atypical of Undetermined Significance (AUS) or Follicular Lesion of Undetermined Significance (FLUS); (Class III), 6 were showing follicular neoplasm or suspicious for a follicular neoplasm (Class IV), 7 samples were suspicious for malignancy (Class V) and 5 samples were positive for malignancy (Class VI). On comparison of ultrasound guided FNAC with histopathology the sensitivity for correct diagnosis was 93%, specificity was 86%, positive predictive value was 37%, negative predictive value was 99% and accuracy was 86%. USG-FNAC is a useful modality for the evaluation and treatment planning of nonpalpable thyroid lesions smaller than5 mmin the maximum diameter. TBSRTC is the best method of reporting but class III and IV are the main pitfall of this system for reporting Thyroid Cytopathology and show high sensitivity, specificity and accuracy.

Ultrasonographic criteria for fine needle aspiration of nonpalpable thyroid nodules 1–2 cm in diameter

PurposeTo investigate the ultrasonographic (US) characteristics for nonpalpable thyroid nodules 1–2cm in diameter and to evaluate the guideline for fine needle aspiration (FNA) in terms of US findings. Materials and methodsBetween June 2005 and November 2006, FNA was performed in 919 thyroid nodules by radiologists. Of these nodules, 51 malignant nodules and 72 benign nodules were finally included. All 123 nodules were analyzed by 3 radiologists if there were the following US characteristics: marked hypoechogenecity, hypoechogenecity, isoechogenecity, hyperechogenecity, microcalcification, coarse calcification, rim calcification, spiculated margin, taller-than-wide shape, irregular shape, hypoechoic rim and honeycomb appearance. The maximum diameters of nodules and thickness of hypoechoic rim were measured. US characteristics relevant as predictors were identified using a Chi-square or Fisher's exact test and odds ratio. We compared the diagnostic efficacy of 3 US criteria for FNA indication. ResultsMicrocalcification, taller-than-wide shape, marked hypoechogenecity, hypoechogenecity, coarse calcification, irregular shape and spiculated margin were significant characteristics of malignant nodules. Isoechogenecity, hypoechoic rim and honeycomb appearance was significant characteristics of benign nodules. Rim or arc calcification, hyperechogenecity and thickness of hypoechoic rim were insignificant. Among 3 US criteria for FNA indication, NFI showed the highest diagnostic efficacy, 98.0% in sensitivity, 75.0% in specificity and 150.0 in odds ratio. ConclusionAs for nonpalpable thyroid nodules 1–2cm in diameter, US characteristics are useful for differentiating between malignant and benign nodules. Malignant US characteristics and honeycombing appearance have significant value in selecting nodules for biopsy and reducing the frequency of the FNA procedure.

Consultation with the Specialist: Thyroid Nodules

Based on strong research evidence, thyroid nodules in children and teenagers are more likely to be malignant than in adults. Based on strong research evidence, a history of ionizing radiation to the head or neck is an independent risk factor for the development of thyroid malignancies. There is strong research evidence, including a recent meta-analysis, supporting the use of fine-needle aspiration biopsy in the evaluation of all pediatric and adolescent patients presenting with a thyroid nodule. The surgical management and postoperative care of pediatric and adolescent patients who have well-differentiated thyroid carcinomas remains controversial, because the rarity of the disease limits the ability to conduct randomized, prospective research studies. Numerous studies have demonstrated that, despite presenting with more advanced disease, pediatric and adolescent patients with thyroid carcinoma have a higher survival rate than adults. The American Thyroid Association has issued strong evidence-based recommendations for the management of medullary thyroid carcinoma, including RET mutation testing and early prophylactic total thyroidectomy in children with high-risk mutations.

ThyroScreen system: High resolution ultrasound thyroid image characterization into benign and malignant classes using novel combination of texture and discrete wavelet transform

Using right equipment and well trained personnel, ultrasound of the neck can detect a large number of non-palpable thyroid nodules. However, this technique often suffers from subjective interpretations and poor accuracy in the differential diagnosis of malignant and benign thyroid lesions. Therefore, we developed an automated identification system based on knowledge representation techniques for characterizing the intra-nodular vascularization of thyroid lesions. Twenty nodules (10 benign and 10 malignant), taken from 3-D high resolution ultrasound (HRUS) images were used for this work. Malignancy was confirmed using fine needle aspiration biopsy and subsequent histological studies. A combination of discrete wavelet transformation (DWT) and texture algorithms were used to extract relevant features from the thyroid images. These features were fed to different configurations of AdaBoost classifier. The performance of these configurations was compared using receiver operating characteristic (ROC) curves. Our results show that the combination of texture features and DWT features presented an accuracy value higher than that reported in the literature. Among the different classifier setups, the perceptron based AdaBoost yielded very good result and the area under the ROC curve was 1 and classification accuracy, sensitivity and specificity were 100%. Finally, we have composed an Integrated Index called thyroid malignancy index (TMI) made up of these DWT and texture features, to facilitate distinguishing and diagnosing benign or malignant nodules using just one index or number. This index would help the clinicians in more quantitative assessment of the thyroid nodules.

Influence of Long-term Statin use in Type 2 Diabetic Patients on Thyroid Nodularity in Iodine-sufficient Area

Statins have marked beneficial effects on lipid profile, but also have pleiotropic actions. A previous study in an iodine-deficient area suggested that statin use is associated with reduced thyroid volume and nodularity. We performed this study to investigate how long-term statin use in type 2 diabetic patients affects thyroid nodularity in iodine-sufficient area.We recruited euthyroid type 2 diabetic patients, receiving statin therapy continuously for at least 5 years (statin group) and, age and sex matched statin-naive type 2 diabetic patients (control group). Subjects with past history of cancer, thyroid disease or treatment with lithium or amiodarone; family history of thyroid cancer; palpable goiter or thyroid nodule, and/or positive thyroperoxidase antibody were excluded. The prevalence, number, and volume of thyroid nodules, size of thyroid were evaluated in all subjects by high resolution ultrasound.Prevalence of non-palpable thyroid nodules of statin group (n=70) and control group (n=98) were 51 and 53%, respectively. There was no difference of prevalence, number, and volume of non-palpable thyroid nodules and size of thyroid between statin and control group. But, the patients aged between 60 and 65 years from statin group showed lower prevalence of non-palpable thyroid nodules than the patients with same age interval from control group (4 out of 12 patients, 33%, statin group; 19 out of 27 patients, 70%, control group; P=0.04).Long-term statin use in elderly type 2 diabetic patients was associated with lesser prevalence of thyroid nodules in an iodine-sufficient area. Our data might support a possible antiproliferative effect of statins on thyroid in old type 2 diabetic patients. But, the effect was not as strong as that in an iodine-deficient area and further studies with enough numbers of subjects and revised design will be needed.

Endocrine Society of India management guidelines for patients with thyroid nodules: A position statement

Thyroid nodules are common. Thyroid cancer is rarer. No guidelines exist for management of thyroid nodules in the Indian context and these recommendations are intended for this purpose. The consensus committee reviewed important articles, including previously published consensus statements. Management points were scored according to the level of evidence. These guidelines cover the clinical evaluation and include the interpretation of imaging and fine needle aspiration cytology of thyroid nodules. The guidelines also cover the management of special situations like thyroid incidentalomas, cystic thyroid lesion and nodules detected during pregnancy. The consensus guidelines represent a summary of current medical evidence for thyroid nodule management and the committee has attempted to optimize the guidelines for the clinical practice setting in India.

Nodular thyroid disease in the erderly

The occurrence of thyroid nodules increases with age [1]. In geographical areas with a normal iodine intake, approximately 10% of the population develops a palpable thyroid nodule. This proportion increases in areas with insufficient iodine intake. Non-palpable thyroid nodules are usually diagnosed by a neck echography carried out for various reasons and are 5-10 folds more common than palpable nodules. When evaluating a thyroid nodule, we must be aware that two conditions require particular attention: a) the possibility of a “hot” (hyperfunctioning) nodule, which can induce thyrotoxicosis; b) the possibility of a malignant nodule. Both these pathological conditions increase with age [2,3]. In particular, elderly patients often show a multinodular goiter, where both hyperfunctioning nodules and hypofunctioning nodules suspicious for malignancy may coexist. When FT3 is high and/or TSH is suppressed a hyperfunctioning nodule should be suspected. In order to confirm this diagnosis the patient should carry out a thyroid scintigram. In the case that both FT3 and TSH are in the normal range, the nodule should be regarded as non-functioning. In this case a thyroid scintigram is not useful whereas a fine needle aspiration (FNAB) is the diagnostic procedure of choice [4]. Both hyperfunctioning and malignant thyroid nodules are more common in elderly patients. Notably, hyperthyroidism is a more serious condition in the elderly than in the young because of an increased risk of cardiac dysfunction. Moreover, thyroid cancer behaves more aggressively in elderly patients. In these patients thyroid cancer is usually less differentiated and lacks the ability to concentrate iodine. Therefore, thyroid cancer metastases cannot be treated with radioiodine. In the case of a hyperfunctioning nodule the therapy of choice is a thyroid lobectomy. In contrast, in the case of a multinodular goiter or of a malignant nodule, a total thyrodectomy is required.

Cytopathologist‐performed ultrasound‐guided fine‐needle aspiration of parathyroid lesions

The gold standard to determine the cause of primary hyperparathyroidism (PHPT) is bilateral neck exploration. As most cases are caused by parathyroid adenoma, there is a movement toward preoperative localization of the abnormal gland by ultrasound and/or Tc(99)-sestamibi scan and minimally invasive parathyroidectomy. Nonpalpable thyroid nodules are common and cannot be differentiated from parathyroid lesions by imaging alone. This study examines cytopathologist-performed ultrasound-guided fine-needle aspiration (UG-FNA) in diagnosis of parathyroid lesions. Between January 1, 2007 and December 31, 2008, seven patients with PHPT or other parathyroid lesions with one or more sonographically-visible thyroid masses underwent cytopathologist-performed UG-FNA with immediate cytological evaluation (ICE). One mass was palpable and nine were nonpalpable. Three parathyroid adenomas, two benign colloid nodules, one papillary carcinoma, three parathyroid cysts, and one thyroid cyst were diagnosed. The nodules in three patients with parathyroid adenomas were identified as follicular lesion/neoplasm on ICE. Additional UG-FNA passes were made to obtain tissue for immunohistochemistry stains, which confirmed parathyroid origin. Two of these patients had a separate benign colloid nodule and one had a thyroid cyst diagnosed by UG-FNA. The PHPT patient with papillary carcinoma on UG-FNA had the malignancy confirmed at surgery and a sonographically occult parathyroid adenoma. The three patients with thyroid cysts identified by radiology were suspected of being parathyroid cysts on the basis of real-time sonographic features at the biopsy table. The clear cyst fluid obtained by UG-FNA had markedly elevated PTH. Cytopathologist-performed UG-FNA can distinguish between parathyroid and thyroid nodules in patients with suspected parathyroid lesions.

Diagnostic value of ultrasound-guided fine needle aspiration biopsy for nonpalpable thyroid nodules

Thyroid sonography and guided fine needle aspiration were performed on 75 nonpalpable thyroid nodules. Uhrasonographic characteristics of nonpalpable thyroid nodules were helpful in distinguishing benign from malignant tumors. Fine-needle aspiration biopsy under uhrasonography is a more useful technique in diagnosing nonpalpable thyroid nodules. Key words: Thyroid; Ultrasonography; Fine-needle aspiration; Cytology; Diagnosis

The role of sonoelastography in the differential diagnosis of neck nodules

Sonoelastography is an imaging technique that provides information on tissue elasticity. Its use as a diagnostic procedure is based on the premise that pathological processes like cancer alter the physical characteristics of the involved tissue. Ultrasonographic studies of the neck can reveal the nonpalpable thyroid nodules, but the nature of these lesions generally has to be established on the basis of FNAB findings. In our hands, sonoelastography displayed a diagnostic accuracy of 86.2% in identifying thyroid nodule malignancy, with positive and negative predictive values (PPV and NPV) of 64% and 94.5%, respectively. In the study of cervical lymph nodes, the results were less impressive (sensitivity 75%, specificity 80%, accuracy 77%, PPV 80%, NPV 70%), but the information obtained with this technique can in our opinion be a useful adjunct to sonographic findings. Indeed, in 5 lymph nodes with sonographic features consistent with malignancy, sonoelastography revealed diffuse elasticity that was indicative of benign disease, which was confirmed by pathological studies. Other nodular lesions of the neck can also be evaluated with sonoelastography, including enlarged parotid glands, but the data in the literature are too limited to allow hypotheses on the role of this imaging modality in this field. Sonoelastography is rapid and simple to perform, and it appears to be a potentially useful tool for the differential diagnosis of neck nodules. This is particularly true of thyroid nodules. Our experience with these lesions indicates that diffuse elasticity is strongly correlated with benign disease. If this finding is confirmed in larger studies, sonoelastography might be used to identify thyroid nodules that do not require immediate biopsy.

Usefulness of ultrasound-guided fine-needle aspiration cytology in the diagnosis of non-palpable small thyroid nodules: Our growing experience

Contradictory approaches have been suggested for the management of non-palpable thyroid nodules. The aim of our study is to evaluate indications and limits of ultrasound-guided fine-needle aspiration cytology (US-FNAC) in the management of non-palpable infracentimetric thyroid nodules. From September 2003 to June 2007 we studied 1043 patients with non-palpable thyroid nodules. We divided our series into three groups according to the diameter of the lesion in order to verify the effectiveness of US-FNAC for lesions <1 cm. We assessed the cases with satisfactory and unsatisfactory results in the 3 groups into which the sample was divided. Our statistical analysis using the z-test showed there was no significant (p=0.05) difference in the percentage distribution of the unsatisfactory results in the 3 groups. FNAC appears to be a useful diagnostic tool also for nodules <1 cm because the percentage of unsatisfactory results is not related to the size of the nodule.

Etiologic discussion and clinical relevance of thyroid ultrasonography in subclinical hypothyroidism. A retrospective study in 1845 patients

Background Acquired subclinical hypothyroidism in adulthood is mainly due to autoimmune thyroiditis. In the absence of a goiter or a palpable firm thyroid, measurement of thyroid antibodies can improve the diagnosis. Whether thyroid antibodies are detected or not, what might be the clinical relevance of ultrasonography in this setting? Methods We studied 1845 cases of subclinical hypothyroidism in adults recruited for symptoms indicative of hypothyroidism or thyroid pathology. All patients were screened for thyroid antibodies and underwent an ultrasonographic thyroid examination. Localisation Multicentric retrospective study. Results Chronic autoimmune thyroiditis was confirmed in 70% of patients. Thyroid antibodies were undetectable in 30% of patients. In all patients, thyroid ultrasound facilitated measurement of the thyroid volume and detection of non-palpable nodules and therefore allowed biopsy. In patients negative for thyroid antibodies, ultrasonography suggested autoimmune thyroiditis in 31% of cases. Ultrasonography did not contribute to diagnosis in a large number of patients without nodules and in case of normal echostructure. The strategy of thyroid hormone replacement therapy was not influenced by ultrasonographic data. Thyroid biopsies detected smears suspected to be cancerous in 10 patients (4%). Cancer was confirmed in nine patients after surgery. Ultrasonography displayed suspicious aspects in six patients. Conclusion In subclinical hypothyroidism, thyroid ultrasonography is not required for the diagnosis of autoimmune thyroiditis but is useful for patients with abnormal thyroid palpation and allows detection of non-palpable thyroid nodules. For patients that were negative for thyroid antibodies, thyroid ultrasonography can improve diagnosis for some patients, allowing detection of autoimmune thyroiditis.

Lithium Toxicity Precipitated by Profound Hypothyroidism

The widespread use of high-resolution ultrasound (US) has allowed the detection of not only nonpalpable thyroid nodules but also parathyroid incidentalomas in the general population. We sought to determine the prevalence of parathyroid incidentalomas in a large group of patients referred for US-guided fineneedle aspiration biopsy (FNAB) of suspected thyroid nodules and to investigate the role of additional parathyroid hormone (PTH) analysis in the washouts of FNAB of suspicious papathyroid nodules in these patients. Between June 2006 and December 2007, US-guided FNAB (US-FNAB) was performed in 6469 patients. Among them, 112 patients (1.7%) underwent additional PTH analysis in FNAB washouts (FNA-PTH) due to suspected parathyroid lesions. A retrospective review of clinical, radiologic, cytologic, and pathologic records was conducted. We evaluated the prevalence of parathyroid adenomas that were detected on thyroid US incidentally as well as the results of FNAB and FNA-PTH in parathyroid adenomas that were confirmed histopathologically. Parathyroid incidentalomas were identified in 14 patients based on pathology and 10 patients based on elevated FNA-PTH. The occurrence of parathyroid incidentalomas was 0.4% (24=6496) on thyroid US. For the detection of the incidentalomas, the positive predictive value (PPV) of thyroid US was 21.4% (24=112). When an inadequate specimen was considered as being of nonparathyroid origin, the sensitivity of FNAB was 41.7%, specificity was 97.7%, accuracy was 85.7%, PPV was 83.3%, and negative predictive value (NPV) was 86% in 112 patients. The diagnostic performance of FNA-PTH in 18 operated nodules showed a sensitivity of 92.9%, specificity of 100%, accuracy of 94.4%, PPV of 100%, and NPV of 80%. Four patients noticed symptoms related to hyperparathyroidism after FNA-PTH analysis. The prevalence of parathyroid incidentaloma was 0.4% (24=6496) in a large series of patients referred for suspected thyroid nodules. The use of FNA-PTH combined with FNAB can help clinicians accurately diagnose parathyroid incidentalomas at the time of US-guided FNAB.

Differential Diagnosis of Benign and Malignant Thyroid Nodules at Elastosonography

Ultrasound of the neck detects a large number of non-palpable thyroid nodules in the population, but it offers poor diagnostic accuracy (the presence of microcalcifications is the only statistically significant criterion indicative of malignancy). The aim of this study is to evaluate elastography, a technique which allows differentiation between pathological and normal tissue by determining its hardness and which could also prove useful in the characterisation of thyroid nodules. In this prospective study, 51 thyroid nodules in 40 consecutive patients were examined (25 women, 15 men, mean age +/- SD, 54 +/- 13.4). Elastosonography was performed by real-time, free-hand technique, using Logos HiVision equipment with a 10 MHz transducer and lesions were classified and scored in 4 classes of hardness. All patients were also examined by grey scale high frequency ultrasound and colour Doppler. Final diagnoses were obtained from cytological and/or histological evaluation. Final diagnoses revealed 11 malignant and 40 benign nodules. Only in two cases ultrasound demonstrated signs useful for a differential diagnosis (intrinsic microcalcifications). Correct differentiation of malignant from benign nodules was obtained by elastosonography in 43 / 51 cases with 5 false positives (FP) and 3 false negatives (FN). Specificity, sensitivity and accuracy were 87.5 %, 81.8 % and 86.2 %, respectively. Predictive negative value (PNV) and predictive positive value (PPV) were 94.5 % and 64 % area under the curve (AUC) 0.86. Elastosonography provides an interesting contribution to the differentiation of malignant and benign thyroid nodules. Particularly worthy of mention is that an entirely elastic nodule pattern was observed only in relation to benign nodules, a result which would suggest that immediate recourse to FNAB might be avoided.