The usefulness of conventional and echo colour Doppler sonography in the differential diagnosis of toxic multinodular goitres

Hashimoto's thyroiditis presenting as a single toxic adenoma (A case report)

Background:

Hashimoto's thyroiditis can be present with a localized palpable nodule though presentation as a hyperfunction "nodule" is extremely rare. The first case of Hashimoto's thyroiditis and hot nodule was reported in 1971 by Warner.

Case Presentation:

We reported a 26-year-old hypothyroid woman in Hashimoto's thyroiditis background with a hyperactive thyroid nodule in both 99mTc and I₁₃₁scintigraphy. The nodule disappeared after eight months of sufficient thyroid hormone replacement therapy.

Conclusion:

Toxic adenoma in hypothyroid patients can be resolved after levothyroxine (L-T4) replacement therapy.

Thyrotoxicosis associated with the use of amiodarone: the utility of ultrasound in patient management

Amiodarone is an anti-arrhythmic drug that commonly affects the thyroid, causing hypothyroidism or thyrotoxicosis. Amiodarone-induced thyrotoxicosis (AIT) is caused by excessive thyroid hormone biosynthesis in response to iodine load in autonomously functioning thyroid glands with pre-existing nodular goitre or underlying Graves' disease (type 1 or AIT 1), or by a destructive thyroiditis typically occurring in normal glands (type 2 or AIT 2). Indeterminate or mixed forms are also recognized. The distinction is clinically useful as AIT 1 is treated predominantly with thionamides, whereas AIT 2 is managed with glucocorticoids. We review the tools used to differentiate type 1 from type 2 thyrotoxicosis, with specific reference to the imaging modalities used.

The Sonographic Features of the Thyroid Gland After Treatment with Radioiodine Therapy in Patients with Graves' Disease

The aim of the study was to describe the typical sonographic features of the thyroid gland in patients with Graves' hyperthyroidism after radioiodine therapy (RIT). Thirty patients (21 female and 9 male) with a mean age of 53 y (standard deviation [SD] ± 11.3) and with previous Graves' disease who had been successfully treated with RIT were enrolled in the study. All were hypothyroid or euthyroid after treatment. The thyroid ultrasound was carried out by a single experienced operator with an 8-MHz linear transducer. Volume, vascularity, echogenicity and echotexture of the glands were noted. The presence of nodules and lymph nodes was also documented. The mean volumes of the right lobe were 2.4 mL ± 2.9 SD (0.6-14) and the left lobe were 1.8 mL ± 1.9 SD (0.4-9.1), with a mean total volume of 4.2 mL ± 4.7 SD (1.3-19.1). Of those who had a pre-treatment ultrasound (23%), the percentage reduction in volume was 87% (p < 0.05); 93% of the glands were hypovascular, with the remaining 7% showing normal vascularity. The glands were hyperechoic and of coarse echotexture. Overall, the sonographic features of the post-RIT gland included a significantly reduced mean total volume of 4.2 mL, hypovascularity, coarse echotexture and hyperechogenicity.

Diagnosis and management of Graves disease: a global overview

Graves disease is an autoimmune disorder characterized by goitre, hyperthyroidism and, in 25% of patients, Graves ophthalmopathy. The hyperthyroidism is caused by thyroid hypertrophy and stimulation of function, resulting from interaction of anti-TSH-receptor antibodies (TRAb) with the TSH receptor on thyroid follicular cells. Measurements of serum levels of TRAb and thyroid ultrasonography represent the most important diagnostic tests for Graves disease. Management of the condition currently relies on antithyroid drugs, which mainly inhibit thyroid hormone synthesis, or ablative treatments ((131)I-radiotherapy or thyroidectomy) that remove or decrease thyroid tissue. None of these treatments targets the disease process, and patients with treated Graves disease consequently experience either a high rate of recurrence, if receiving antithyroid drugs, or lifelong hypothyroidism, after ablative therapy. Geographical differences in the use of these therapies exist, partially owing to the availability of skilled thyroid surgeons and suitable nuclear medicine units. Novel agents that might act on the disease process are currently under evaluation in preclinical or clinical studies, but evidence of their efficacy and safety is lacking.

A Case of simultaneous occurrence of Marine - Lenhart syndrome and a papillary thyroid microcarcinoma

BACKGROUND

Marine-Lenhart syndrome is defined as the co-occurrence of Graves' disease and functional nodules. The vast majority of autonomous adenomas are benign, whereas functional thyroid carcinomas are considered to be rare. Here, we describe a case of simultaneous occurrence of Marine-Lenhart syndrome and a papillary microcarcinoma embedded in a functional nodule.

CASE PRESENTATION

A 55 year-old, caucasian man presented with overt hyperthyroidism (thyrotropin (TSH) <0.01 μIU/L; free thyroxine (FT4) 3.03 ng/dL), negative thyroid peroxidase and thyroglobulin autoantibodies, but elevated thyroid stimulating hormone receptor antibodies (TSH-RAb 2.6 IU/L). Ultrasound showed a highly vascularized hypoechoic nodule (1.1 × 0.9 × 2 cm) in the right lobe, which projected onto a hot area detected in the 99mtechnetium thyroid nuclear scan. Overall uptake was increased (4.29%), while the left lobe showed lower tracer uptake with no visible background-activity, supporting the notion that both Graves' disease and a toxic adenoma were present. After normal thyroid function was reinstalled with methimazole, the patient underwent thyroidectomy. Histological work up revealed a unifocal papillary microcarcinoma (9 mm, pT1a, R0), positively tested for the BRAF V600E mutation, embedded into the hyperfunctional nodular goiter.

CONCLUSIONS

Neither the finding of an autonomously functioning thyroid nodule nor the presence of Graves' disease rule out papillary thyroid carcinoma.

The role of the resistive index in Hashimoto's thyroiditis: a sonographic pilot study in children

OBJECTIVE

The role of Doppler ultrasonography in the diagnosis of diffuse thyroid diseases is not well established. In particular, Doppler ultrasonography findings in children with Hashimoto's thyroiditis are very limited. We examined gray-scale and Doppler ultrasound findings in Hashimoto's thyroiditis in children in an attempt to understand the feasibility of future prospective controlled studies.

MATERIALS AND METHODS

Twenty-one children with newly diagnosed Hashimoto's thyroiditis were recruited in the study. The patients were euthyroid or had subclinical hypothyroidism at the time of the ultrasonography examination. According to the color Doppler scale developed by Schulz et al., thyroid glands were classified into four patterns based on visual scoring and the mean resistive index (RI), which was calculated via measurements from both lobes, and these results were compared with gray-scale findings.

RESULTS

The mean RI value, calculated as the mean of the RI values of both lobes obtained from each patient, was found to be 0.57 ± 0.05 (range 0.48-0.67) cm/sn. The distribution of thyroid classifications was as follows: Pattern 0, n = 7; Pattern I, n = 6; Pattern II, n = 4; and Pattern III ("thyroid inferno"), n = 4. The mean RI values in patients with normal or near-normal gray-scale findings (n = 10) and patients with more substantial gray-scale changes (n = 11) were not significantly different and were lower than the values in normal children previously presented in the literature.

CONCLUSION

The results indicated that the RI may be more sensitive than other ultrasound parameters for the diagnosis of Hashimoto's thyroiditis.

Benign conditions of the thyroid gland

Infectious and autoimmune diseases account for the majority of benign conditions of the thyroid gland. They are usually diagnosed and followed by clinical examination and laboratory analyses, but when imaged, ultrasonography and computed tomography are the modalities of choice. In particular, fine needle aspiration under ultrasound guidance may be invaluable for diagnostic and therapeutic purposes.

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.

Color-flow doppler sonography in patients with subclinical thyroid dysfunction

OBJECTIVE

To assess the value of color-flow Doppler sonography (CFDS) in evaluating intrathyroidal blood flow and velocity in patients with subclinical thyroid dysfunction.

METHODS

In this prospective study, patients with subclinical hypothyroidism, patients with subclinical hyperthyroidism, and euthyroid patients without known thyroid autoimmune disease who served as controls were included. Subclinical thyroid dysfunction was defined as normal se-rum free thyroxine (FT4) and free triiodothyronine (FT3) in the presence of high (subclinical hypothyroidism), or low-suppressed (subclinical hyperthyroidism) serum thyrotropin (TSH) levels. Serum FT4, FT3, TSH, and antibodies to thyroid peroxidase and thyroglobulin were measured in all participants. In addition, TSH receptor antibody levels were determined in patients with subclinical hyperthyroid-ism. All participants underwent conventional sonography and CFDS. Mean peak systolic velocity (PSV) and resistive index were obtained from multiple extranodular thyroid parenchyma samplings and inferior thyroid artery measurements.

RESULTS

The study population included 27 patients with subclinical hypothyroidism, 15 patients with subclinical hyperthyroidism, and 20 euthyroid patients. Patients with subclinical hypothyroidism had significantly higher mean intrathyroidal PSV values than control patients (19.9 +/- 5.6 cm/s vs 15.7 +/- 4.4 cm/s; P = .008), whereas patients with subclinical hyperthyroidism had significantly higher mean PSV values than control patients at the inferior thyroid artery level (29.7 +/- 10.7 cm/s vs 21.9 +/- 6.8 cm/s; P = .014). Compared with control patients, a greater proportion of patients with subclinical hypothyroidism and patients with subclinical hyperthyroidism had marked CFDS patterns (78% vs 15% [P<.001] and 53% vs 15%; [P<.001], respectively). A significant association was found between positivity for thyroid autoantibodies and intense CFDS patterns. No correlation was found between TSH or thyroid hormone levels and CFDS pattern or blood flow velocity.

CONCLUSION

We have demonstrated that significantly increased thyroid blood flow velocity and vascularity are already present in patients with mild thyroid dysfunction.

A semi-quantitative approach to compare high-sensitivity power Doppler sonography and conventional power Doppler sonography in the assessment of thyroid vascularity

BACKGROUND

Ultrasound is a useful imaging tool in the assessment of thyroid glands, and Doppler ultrasound helps in the evaluation of thyroid vascularity. This study was undertaken to evaluate the difference in the thyroid vascularity demonstrated on the state-of-the-art high-sensitivity power Doppler sonography (HSPDS) and the conventional power Doppler sonography (PDS), and to investigate the feasibility of using a customized algorithm with image-processing software for semi-quantitative assessment of thyroid vascularity.

METHODS

A total of 25 healthy volunteers were included in the study, and each subject had two thyroid ultrasound examinations with HSPDS and PDS, respectively. High sensitivity and conventional power Doppler sonograms of the thyroid glands were taken and recorded. To evaluate the vascularity of thyroid lobes quantitatively, a customized algorithm using the software Matlab was developed and used to analyze the ultrasound images. The vascularity of thyroid lobe (i.e., region of interest, ROI) was expressed as the vascular index (VI), which is the ratio of the number of color pixels to the total number of pixels within the ROI.

RESULTS

Results showed that thyroid vascularity was detected in all thyroid lobes on both HSPDS and PDS. The mean VI of the thyroid lobes on HSPDS (right lobe, 0.31 +/- 0.08; left lobe, 0.32 +/- 0.07) was significantly higher than on PDS (right lobe, 0.18 +/- 0.09; left lobe, 0.16 +/- 0.08) (p < 0.05). There was no significant difference in the VI between the right and left thyroid lobes (p >0.05). On HSPDS, 96% of the thyroid lobes showed a VI <0.5, while 96% of thyroid lobes had a VI <0.3 on PDS.

CONCLUSIONS

HSPDS is more sensitive than PDS in the detection of thyroid vascularity. The developed algorithm can quantify the color pixels on power Doppler sonograms, which is useful for objective assessment of thyroid vascularity.

The role of imaging in Graves’ disease: A cost-effectiveness analysis

According to many guidelines, scintigraphy remains the first suggested diagnostic procedure in hyperthyroid patients in spite of the widespread availability of ultrasounds. The aim of this study was to evaluate the cost-effectiveness of sonography versus scintigraphy in the management of Graves's disease, and to assess ultrasound features suggesting cancer in detecting thyroid nodules. Among 1470 hyperthyroid patients evaluated in our department from 2002 to 2005, 426 (29%) had Graves' disease: echographic and scintigraphic features were not suggestive of GD in 20/426 (4.8%) and 11/426 (2.6%) patients, respectively (p=0.763), even if one of the two procedures was almost always diagnostic. Ultrasound identified 68/426 (16%) patients with a concomitant solid lesion, while scintigraphy detected only 9/426 (2.1%) "cold" nodules (p<0.001). Thyroid cancer was diagnosed in 30/68 (47.7%) patients. Malignancy presented at ultrasound investigation blurred margins (26.7% versus 15.8%), microcalcifications (33.3% versus 28.9%) and an anteroposterior and transverse diameter ratio>or=1 (73.3% versus 71.1%); more frequently than benign nodules, but this was not statistically significant. The total cost to obtain a diagnosis by ultrasound was euro14645.34 (euro13312.5 for echography+euro1332.84 for scintigraphy in the 29 patients "negative" at echographic evaluation for GD) versus euro19922.71 by scintigraphy (euro19578.96 for scan+euro343.75 for ultrasounds in the 11 patients "negative" at scintigraphy). Our data show no difference in terms of diagnosis between sonography and scintigraphy. Indeed, scintigraphy was less sensitive in detecting nodules (often of malignant nature) than ultrasound, and, moreover, with a consequent increase of the direct cost of nodule management when scintigraphy is the first line procedure. In conclusion, according to our results, we suggest that ultrasounds with color-Doppler evaluation should be performed as first step in all hyperthyroid patients, and that scintigraphic examination should be limited only to the uncommon cases, where physician's observation, laboratory assays and/or ultrasounds are not diagnostic.

Color flow Doppler sonography for the etiologic diagnosis of hyperthyroidism

Color flow Doppler sonography (CFDS) is gaining importance for the functional evaluation of the thyroid disorders. We aimed to determine the value of CFDS for the etiological diagnosis of hyperthyroidism. Fifty-five patients with hyperthyroidism (29 Graves' disease [GD] and 26 toxic adenoma [TA]), 24 patients with Hashimoto's thyroiditis (HT), and 39 euthyroid controls were included. Etiological diagnoses were carried out using standard methods. Conventional gray scale sonography was performed, followed by CFDS. Doppler patterns of the glands were scored and peak systolic velocity (PSV) measurements were obtained from intrathyroidal, perithyroidal, and perinodular vasculature. Vascular patterns were significantly more prominent, and the mean PSV values were significantly higher in the GD patients compared to the HT patients ( p < 0.001) and controls ( p < 0.001). Perinodular and intranodular signals and the mean perinodular PSV values were significantly higher in TAs compared to controls. CFDS could differentiate the untreated GD from the HT, which had similar gray scale findings. Hot nodules could also be differentiated from cold nodules with more prominent vascular patterns and significantly higher PSV values. As an inexpensive, fast, and noninvasive imaging procedure, CFDS could be helpful in the initial clinical evaluation and may avoid scintigraphy in a substantial number of thyrotoxic patients.

Relationship between the sonographic appearance of the thyroid and the clinical course and autoimmune activity of Graves' disease

PURPOSE

The aim of this study was to investigate the relationship between thyroid echogenicity and clinical course/immunologic parameters in Graves' disease.

METHODS

Two hundred and six outpatients with Graves' disease (31 men, 175 women; 46 +/- 23 years old) were studied with thyroid sonography and color Doppler sonography. Forty-five patients were treated for active hyperthyroidism, 161 were euthyroid (85 immediately before withdrawal of antithyroid drug at maintenance doses, 76 in stable remission after withdrawal of antithyroid treatment). Free triiodothyronine, free thyroxine, thyrotropin, and disease-specific autoantibodies (antithyrotropin-releasing hormone antibody) were determined in all patients.

RESULTS

The ultrasound images were classified on the basis of homogeneous, finely unhomogeneous, or micronodular appearance. The proportion of unhomogeneous plus micronodular patterns was greater in hyperthyroid (77.8%) than in euthyroid patients (62.1%). In the latter group, the pattern distribution was significantly different in patients who were antibody positive relative to patients who were antibody negative (p < 0.01). In the stable remission subgroup, the pattern distribution differed according to thyrotropin levels (p < .01). There was a correlation between echopattern and color Doppler sonography as vascularization variables progressively increased in the transition from homogeneous to unhomogeneous and micronodular echopattern (most evident echotexture changes).

CONCLUSIONS

A sonographic-based classification in Graves' disease can distinguish subgroups of patients with different clinical courses and disease activity. This procedure is easy to perform and correlates well with clinical findings.

Hypothyroid Hashimoto's thyroiditis with scintigraphic and echo-color Doppler features mimicking autonomous adenoma

We investigated a 48-yr-old woman on L-T4 therapy (100 microg/d) for primary autoimmune hypothyroidism, diagnosed 15 yr earlier, presenting a firm oval lump in the right thyroid lobe and symptoms of mild thyrotoxicosis. Free T4, free T3, TSH, anti-thyroperoxidase, anti-TG and anti-thyroid microsomal antibodies were determined. Thyroid US and color flow Doppler sonography (CFDS), 99mTechnetium (99mTc), radioiodine scintiscan and US guided fine needle aspiration cytology (FNAC) were performed. On L-T4 therapy, thyroid function tests showed subclinical hyperthyroidism with high anti-thyroid antibody titers. Thyroid US and CFDS revealed a voluminous hypoechoic hypervascularized nodule with increased peak systolic velocity (type III pattern) in the right lobe; the extranodular tissue volume was markedly reduced and hypoechoic. The presence of an autonomous functioning nodule associated to Hashimoto's thyroiditis (HT) was suspected, L-T4 therapy was temporary withdrawn, and the patient re-evaluated 2 months later. Off L-T4 therapy, thyroid function tests revealed marked primary hypothyroidism, while thyroid US and CFDS were unchanged. 99mTc thyroid scan showed a focal increased uptake corresponding to the nodule in the right lobe with nearly absent uptake in the remaining thyroid tissue. Only a faint, patchy thyroid distribution of 131I was detected by radioiodine scan, and RAIU was very low. Cytological examination by FNAC revealed normal follicular cells and several lymphocytes. The final diagnosis was therefore hypothyroid HT with pseudo-nodular thyroid tissue of the right lobe. To our knowledge, this is the first report of HT mimicking both scintigraphic and CFDS features of an autonomous functioning nodule.

TSH-receptor antibody measurement for differentiation of hyperthyroidism into Graves' disease and multinodular toxic goitre: a comparison of two competitive binding assays

OBJECTIVES

Graves' disease is characterized by stimulating autoantibodies to the TSH-receptor (TRAb). The aim of this study was to compare the performance of a new TRAb assay based on competitive binding to recombinant human TSH-receptors (H-TRAb) with an assay employing purified porcine TSH-receptors (P-TRAb). Furthermore, to evaluate the applicability of the H-TRAb assay to discriminate between patients with hyperthyroidism due to Graves' disease (GD) and multinodular toxic goitre (MNTG).

DESIGN AND MEASUREMENTS

H-TRAb and P-TRAb were measured in patients with newly diagnosed hyperthyroidism due to GD (n = 106) and MNTG (n = 94). For comparison, TRAb was measured in patients with primary autoimmune hypothyroidism, euthyroid subjects with an enlarged thyroid gland by ultrasound, and healthy controls (n = 100 for each group). Patients were consecutively included from a population survey.

RESULTS

If the cut-off values recommended by the manufacturer for TSH-receptor antibody positivity were used for evaluation, the sensitivity of the H-TRAb assay vs. the P-TRAb assay in diagnosing GD was: 95.3/67.9% (P < 0.001). Specificity was (H/P-TRAb): 99/99%. The sensitivity of P-TRAb was increased if the upper 97.5% limit of measurements in controls was used as cut-off (H-TRAb vs. P-TRAb: 95.3/80.2%, P < 0.001). Specificity (H/P-TRAb): 98/98%. The difference between assay performance may partly be due to a better technical performance of the H-TRAb assay with more reliable results in the low range of measurements. However, even in GD patients with clearly measurable TRAb, 25% had a P-TRAb < 50% of the value expected from the H-TRAb measurement. This suggests that a subgroup of patients produce TRAb with a higher affinity for the human than the porcine TSH receptor. A relatively high proportion of patients with MNTG were TRAb positive (H-TRAb/P-TRAb: 17/9%). Characteristics of H-TRAb positive and negative MNTG patients were compared. There was no difference between size of thyroid gland and number of nodules by ultrasonography. H-TRAb positive patients had significantly higher serum T4 and T3 and a greater number were TPO-Ab positive.

CONCLUSIONS

H-TRAb diagnosed Graves' disease with a high sensitivity and specificity than P-TRAb. The high occurrence of TRAb in multinodular toxic goitre might in part reflect an overlap between Graves' disease and multinodular toxic goitre in some patients.