Elastography of the thyroid.

Thyroid nodules are very common, while thyroid cancer is rare and has a very good prognosis. Thyroid nodule ultrasound characterization performed by experienced clinicians allows the selection of the tumours to be punctured and guiding fine needle aspiration (FNA). FNA provide cytology information able to differentiate benign tumours from cancer in approximately 80% of cases. However, it remains difficult to identify thyroid cancers with ultrasound imaging, as demonstrated by the very low rate of cancers detected in all of the carried out FNA (approximately 5%). As a majority of thyroid cancers are hard, the stiffness evaluation has become part of nodular characterization. Since 2005, elastography has been used for the evaluation of thyroid nodules; quasi-static elastography was the first technique available and used, at first, an external pressure induced by the probe, which was then replaced by carotid internal excitation allowing improvement in sensitivity. Semi-quantitative analysis allows comparison of tissue elasticities between tissue with elasticity anomalies and normal tissue and provides therefore useful analytic information. Shear wave elastography (SWE) provides a map of the elasticity in a region and allows stiffness quantification of lesions in kilopascals in order to reinforce the predictive value of malignancy. A tumour whose stiffness is greater than 65kPa or for which the stiffness ratio is greater than 3.7 compared to surrounding healthy tissue is highly suspicious. SWE may enable the detection of malignant follicular tumours that currently escape detection by the ultrasound-guided ultrasound/aspiration cytology couple. Lymph node metastasis of papillary thyroid cancer can also be detected by elastography due to its increased stiffness.

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

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

Good practice guide for cervical ultrasound scan and echo-guided techniques in treating differentiated thyroid cancer of vesicular origin.

Good practice guide for cervical ultrasound scan and echo-guided techniques in treating differentiated thyroid cancer of vesicular origin. American, European and French Recommendations for the treatment of differentiated vesicular thyroid cancer were recently published. Cervical ultrasound scanning is now considered a key examination in the follow-up of these cancers. This examination is noninvasive, easy to perform and to obtain, is not costly, but remains operator-dependent. To date, there are no recommendations published that assemble all the technical aspects, results, indications and the limits of this examination in the initial medical report and the follow-up of these cancers. In order to standardise the procedure and validate the quality of the examination, a workgroup made up of a panel of experts particularly involved in carrying out ultrasound scans was set up. The aim was to draw up a good practice guide for performing cervical ultrasound scans and echo-guided techniques in treating patients with differentiated thyroid cancer of vesicular origin. The main objectives are to: (a) standardise the procedure and reports, (b) define the criteria for establishing whether lesions identified during a cervical ultrasound scan are malignant or benign, (c) standardise the indications for carrying out cytological tests and an in situ assay of markers, (d) help doctors to select the patients who ought to receive a cervical ultrasound scan and or cytological tests, (e) discuss how frequently the examinations should be carried out depending on the risk of recurrence.

[Thyroid nodule management: ultrasonography, fine-needle cytology]. / Conduite à tenir devant un nodule thyroïdien: échographie, cytoponction.

All ultrasound examinations for thyroid nodule should include a malignancy risk assessment based on the markedly hypoechoic nature of the nodule, presence of microcalcifications, ill-defined margins, nodule with shape taller than wide and intra-nodular hypervascularity at color Doppler. In patients with multinodular thyroid gland, precise nodule mapping is necessary to allow accurate follow-up of each nodule, correctly identify which nodule(s) is hyper functioning on iodine scan (if done) and guide fine needle aspiration (FNA) of suspicious nodules. As such, all reports of US examinations for thyroid nodule(s) should include a diagram or map of the nodule(s). An evaluation of cervical lymph nodes also helps to determine the malignancy risk. The main US features for malignant adenopathy include: rounded lymph node, loss of normal echogenic fatty hilum, and loss of normal hilar vascularization. Several patterns are highly suggestive of thyroid cancer metastasis: microcalcifications, cystic components, hyperechoic nodes, mimicking thyroid tissue. FNA is a routine procedure in experienced hands. It is the best test to determine which nodule(s) needs to be surgically removed. Thyroglobulin assay on needle-washing fluids after FNA is mandatory when lymph node metastasis is suspected. Preoperative lymph nodes mapping with neck ultrasound is commonly repeated prior to surgery to assess the need for node dissection in patients with proven thyroid malignancy.

[Imaging of thyroid nodules]. / Imagerie du nodule thyroïdien.

Ultrasonography and scintigraphy are the first line diagnostic imaging modalities for the evaluation of thyroid nodules. Scintigraphy provides functional informations, mainly detection of hot nodules. US provides accurate morphologic evaluation and it may sometimes suggest malignancy. US is the modality of choice for follow-up of non resected nodules and is very useful for guidance during biopsy. CT and MRI are mainly used for preoperative evaluation of thyroid nodules.

[Results of ultrasonographic and cytologic follow-up of 311 initially non-suspicious thyroid nodules]. / Résultats de la surveillance échographique et cytologique de 311 nodules thyroïdiens initialement non suspects.

The follow-up of initially non suspect thyroid nodules after fine needle biopsy is not completely worked out. Since 1985, we have entered upon a prospective study concerning the followup of thyroid nodules supposed to be benign after initial evaluation. What are the nature and the frequency of means to be used for their follow-up? Three hundred and eleven nodules are followed up on a mean duration of 2.44 years. The follow-up of 65 of them is 4 years or more. The follow-up of 120 others is 3 to 4 years; 197 nodules are followed up during 2 to 3 years. A physical examination, an ultrasonography completed with a fine needle biopsy or an ultrasonically guided fine needle biopsy are worked out every year. Twenty-three per cent of initial biopsies are non significant and 90% of them are ultrasonically guided biopsies. At the end of the study, the repeating biopsies reduce to 6% the non significant biopsies ratio. Four histological thyroid cancers are detected in three female patients 1 year, 2 years and 5 years after the initial evaluation. Ultrasound alterations of nodules are observed in case of very suspect biopsies. Ninety-six per cent of the followed up thyroid nodules remain not cytologically suspect. These findings allow us to propose the following guidelines for the assessment of a non suspect thyroid nodule: half-yearly or yearly physical examination, yearly or biennial ultrasonography, repeat biopsy after 2 or 3 years when clinical or ultrasound suspect modification is wanting.

[Nodular or pseudo-nodular Hashimoto thyroiditis. Value of cytologic examination]. / Thyroïdites de hashimoto à aspect nodulaire ou pseudo-nodulaire. Intérêt de l'examen cytologique.

OBJECTIVES: Nodular or pseudo-nodular aspects of Hashimoto's thyroiditis raise the problem of the association with a differentiated carcinoma or a non Hodgkin's lymphoma. METHODS: We looked for patients needing surgery in 165 cases of Hashimoto's thyroiditis. For this purpose, we used fine needle aspiration cytology. RESULTS: We found a differentiated carcinoma in 4% of cases and a non Hodgkin's lymphoma in 1% of cases. CONCLUSION: In nodular or pseudo-nodular aspects of Hashimoto's thyroiditis, fine needle aspiration cytology is helpful for the nodule diagnosis and for the selection of suspicious nodules only to be referred to surgery.

[Echography of thyroid nodules. The echography specialist facing the clinician's requirements]. / Echographie des nodules thyroïdiens. L'échographiste face aux exigences du clinicien.

The risk of malignancy in cases of unique non-functional thyroid nodules ranges from 5 to 20% and since definitive diagnosis can only be provided by the pathology examination, surgical removal could be planned in all cases. The clinician however also has the objective of proposing surgery to as few patients with benign nodules as possible and thus calls upon the echographist to help distinguish between malignant and benign nodules. Thus orders for echography carry an intrinsic request for diagnostic arguments, a precise analysis of the characteristics of the nodule and a description of possible multinodular dystrophy as well as an estimation of the probability of malignancy. The echographist's report must include a precise description of each thyroid lobe, the localization of the nodule, its size, contour, echostructure, echogenicity and calcifications. The cervical lymph node chains must also be explored. An analysis of the surrounding parenchyma can frequently confirm multinodular dystrophy. The size of the nodule is the determining factor in predicting malignancy. While for very small nodules, less than 1 cm in diameter, the malignant nature cannot be reasonably predicted, and inversely for very large nodules, invading an entire lobe, it is usually evident, for intermediate sized nodules, echography is a strategic diagnostic tool. No sign is pathognomonic but an association of arguments can favour malignancy: an unique isolated nodule, irregular contours, lymph node enlargement greater than 1 cm. Hypoechogenicity is another important characteristic with a positive predictive value of 50% to 63%. Overall, the sensitivity of echography is good at 75% with specificity of 61 to 83%.(ABSTRACT TRUNCATED AT 250 WORDS)

[Echography of thyroid nodules. What the clinician is waiting for]. / Echographie des nodules thyroïdiens. Ce qu'en attend le clinicien.

Although modern high-resolution real time ultrasound equipment permits excellent visualisation of the thyroid nodules, their ultrasonic appearance and characteristics do not accurately predict the histological result. Ultrasound allows the whole thyroid and adjacent lymph nodes to be examined. It is regarded as valuable in differentiating between solid and cystic lesions and single or multiple lesions. But predictive positive values of ultrasound in suggesting malignant diagnosis is not so doubtful as it can be said. An hypoechoic lesion is more often malignant and it can be one criterion among many which can help clinician to select patients who must undergo surgery. Ultrasound guided fine needle biopsy is useful in these cases.