Ultrasonography for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism: comparison with (99m)technetium sestamibi scintigraphy

OBJECTIVE: To determine the utility of ultrasonography for the preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism, and to compare this method with (99m)technetium sestamibi scintigraphy. DESIGN: The results of ultrasonography for localization of enlarged parathyroid glands were determined in 120 consecutive patients with primary hyperparathyroidism and compared with findings at surgery (n = 86) and with the results of (99m)technetium sestamibi scintigraphy (n = 99). PATIENTS: All patients had biochemically documented primary hyperparathyroidism based on elevated serum calcium and 'intact' parathyroid hormone measured by immunoassay. Patients with prior parathyroid surgery or secondary hyperparathyroidism were excluded. MEASUREMENTS: High-resolution ultrasonography was performed by a single observer. (99m)Technetium sestamibi scintigraphy was performed using early and delayed (2-h) views, and correlated with simultaneous thyroidal 123I uptake in most patients. RESULTS: Ultrasonography detected putative enlarged parathyroid glands in 92 of 120 unselected patients (77%). It correctly predicted surgical findings in 64 of 86 patients undergoing surgery (74%), including 61 of 72 patients with solitary eutopic parathyroid adenomas (84%), but only two of eight patients with solitary ectopic adenomas, and only one of six patients with multigland parathyroid disease. Sestamibi scintigraphy was positive in 87 of 99 unselected patients (88%), a higher proportion than ultrasonography (P < 0.05), reflecting superior sensitivity for the detection of ectopic parathyroid adenomas. For 74 patients undergoing parathyroid surgery who underwent both imaging tests there was no statistically significant difference between ultrasonography and sestamibi scintigraphy in ability to correctly predict surgical findings (74%vs. 82%, respectively) or in positive predictive value (93%vs. 90%, respectively). However, sestamibi scintigraphy was clearly more sensitive for ectopic parathyroid adenomas, providing correct localization in 8/8 cases. When one test was negative, testing with the second method was usually positive, improving the likelihood of a positive result to 98% when both tests were employed. CONCLUSIONS: Ultrasonography can be a sensitive and accurate method for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism, comparable in overall utility to sestamibi scintigraphy. These results suggest that a strategy of initial testing with one or the other method, followed by the alternate imaging test if the first test is negative, would provide correct parathyroid imaging in most patients without prior parathyroid surgery.     

Technetium-99m-sestamibi subtraction scintigraphy vs. ultrasonography combined with a rapid parathyroid hormone assay in parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach

OBJECTIVE: To determine the sensitivity and positive predictive value (PPV) of subtraction scintigraphy (SS) vs. ultrasonography (US) of the neck combined with rapid intact parathyroid hormone (iPTH) assay in US-guided fine-needle parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach. DESIGN: The results of SS for localization of parathyroid adenoma were determined in 121 patients with primary hyperparathyroidism (pHPT) and compared with findings at surgery and with the results of US alone (in patients without nodular goitre) and US in combination with the iPTH assay in US-guided fine-needle aspirates (FNAs) of suspicious parathyroid lesions (in patients with concomitant nodular goitre). PATIENTS: All 121 patients had biochemically documented pHPT; all were referred for first-time surgery. MEASUREMENTS: SS was performed with 99mTc-sestamibi and 99mTc-pertechnetate. High-resolution US of the neck was performed by a single endocrine surgeon and combined with US-guided FNAs of suspicious parathyroid lesions in all patients with nodular goitre (n = 43). RESULTS: The sensitivity and PPV of SS were significantly higher in patients without vs. with goitre (89.3% and 95.7%vs. 74.3% and 76.5%, respectively; P < 0.001). The sensitivity and PPV of US were significantly higher in patients without vs. with goitre (96% and 97.3%vs. 67.7% and 71.9%, respectively; P < 0.001). The iPTH assay of US-guided FNAs of suspicious parathyroid lesions in patients with nodular goitre significantly improved both the sensitivity and PPV of US imaging (90.7% and 100%, respectively), allowing for an accurate choice of surgical approach in 118 (97.5%) of 121 patients. SS was more accurate than US alone in detection of ectopic parathyroid adenomas. However, US alone was characterized by a higher sensitivity in detection of small parathyroid adenomas (< 500 mg) at typical sites (P < 0.01). CONCLUSIONS: Both the sensitivity and PPV of SS and US alone are comparable, with significantly less accurate results obtained in patients with goitre. In cases of equivocal results of US and/or in patients with concomitant goitre, an iPTH assay in US-guided FNAs of suspicious parathyroid lesions may be used to establish the nature of the mass, distinguish between parathyroid and nonparathyroid tissue (goitre, lymph nodes) and improve the accuracy of US parathyroid imaging, allowing for successful directing of surgical approach in a majority of patients.     

Utility of 99mTc-sestamibi scintigraphy as a first-line imaging procedure in the preoperative evaluation of hyperparathyroidism

OBJECTIVE The use of preoperative imaging in patients with hyperparathyroidism remains controversial. Many of the available techniques are insufficiently sensitive and specific to justify their routine use. We have evaluated the Sensitivity and specificity of ^99mTc-sestamibi scintigraphy in the management of patients with different forms of hyperparathyroidism. DESIGN Preoperative imaging evaluation was carried out by sclntigraphic detection of pathological parathyroid glands using ^99mTc-sestamibi as a radiotracer; confirmation of scan findings was obtained surgically. PATIENTS A group of 25 patients with primary (n= 21) or secondary (n=4) hyperparathyroidism were studied. All were considered for surgical treatment. MEASUREMENTS In all cases parathyroid imaging was carried out by ^99mTc-sestamibi scintigraphy together with at least one other imaging technique which included CT-scan, ultrasonography, MRI or ²⁰¹TI/^99mTc subtraction scintigraphy. Blood tests included measurements of total calcium and PTH. RESULTS ^99mTc-sestamibi scintigraphy correctly localized 20 out of 21 adenomas, giving a sensitivity of 95.2%, markedly higher than that obtained with the other imaging techniques (ultrasonography 75%, ²⁰¹TI/^99mTc subtraction scintigraphy 57.1%, CT-scan 41.7% and MRI 33%). Of a total of 17 glands identified surgically as hyperplastic and confirmed by pathological examination, ^99mTc-sestamibi scintigraphy showed a positive image in 10, corresponding always to the larger abnormal glands (sensitivity 58.8%, higher than that observed with the other techniques). No false positive images were obtained with ^99mTc-sestamibi. All the ectopic adenomas (n= 3) were identified preoperatively, which contributed significantly to the surgical approach. CONCLUSION In patients with hyperparathyroidism, ^99mTc-sestamibi scintigraphy may be used as the single imaging technique as it shows a very high sensitivity and specificity in the preoperative localization of pathological parathyroid glands; the benefit of localizing parathyroid tissue prior to surgery in cases of ectopic adenomas clearly indicates that when an imaging procedure is required, this technique may be of great help in the management of hyperparathyroidism.     

Advantages of combined technetium-99m-sestamibi scintigraphy and high-resolution ultrasonography in parathyroid localization: comparative study in 91 patients with primary hyperparathyroidism

OBJECTIVE: To evaluate the usefulness of the combination of Tc-sestamibi/Tc-pertechnetate subtraction scintigraphy (SS) and high-resolution neck ultrasonography (US) in patients with primary hyperparathyroidism (pHPT) undergoing parathyroidectomy. DESIGN AND METHODS: Ninety-one patients with proved pHPT were studied, excluding patients with persistent or recurrent disease. There were 65 (71.4%) women and 26 (28.6%) men, with a median age of 59 years (range 18-78 years). All patients underwent both SS and US prior to surgery, and the results were compared with operative and histological findings. The intraoperative quick-parathyroid hormone assay was available for 52 (57.1%) patients. When multiglandular disease was found, both SS and US were considered truly positive only when at least two enlarged parathyroid (PT) glands had been localized. RESULTS: Eighty-three (91.2%) solitary PT adenomas and three (3.3%) carcinomas were found. Moreover, two (2.2%) patients had a double adenoma and three (3.3%) patients had diffuse PT hyperplasia. The overall sensitivity of combined SS+US was 94.5% (86.8% and 80.4% for SS and US respectively). There was a significant (P<0.05, Student's t-test) difference in size between the PT glands correctly identified and undetected by SS, whereas the site of the removed PT tumors significantly (P<0.05, Fisher exact test) influenced only the US sensitivity. CONCLUSIONS: When the preoperative localization of the PT glands is chosen, the combination of SS and US represents a reliable noninvasive localization technique and should be considered for use in each patient with pHPT undergoing surgery.     

The role of imaging techniques in the study of renal osteodystrophy

Secondary hyperparathyroidism is the most common form of this condition found in renal osteodystrophy. Enlarged parathyroid glands are the rule in severe secondary hyperparathyroidism because of a marked parathyroid cell hyperplasia. For several years, ultrasonography, computed tomography, and scintigraphy with thallium201-technetium99 have been useful techniques to identify enlarged parathyroid glands. More recently, ultrasonography with color Doppler and parathyroid scintigraphy with 99mTc-sestamibi have proved to be useful as well. Computed tomography and magnetic resonance imaging can be used, but their sensitivity is similar to ultrasonography and they cost more. Ultrasonography with color Doppler signals has made it possible to evaluate tissue blood supply, an aid in differentiating thyroid nodules. The degree of blood supply may be an indirect index of cell proliferation when there is neither necrosis nor calcification, because an enriched blood supply suggests vigorous cell growth and nodule formation. Scintigraphy with 99mTc-sestamibi allows identification of ectopic glands, including those located in the mediastinum, and also provides functional information. Sestamibi uptake is closely related to both parathyroid hormone levels and to the histological type of parathyroid proliferation. In our experience, when hyperparathyroidism is not too severe, 2 weeks after 2 g of calcitriol is administered intravenously, these scintigraphic images can disappear (inhibition test). This suggests a possibility for a medical treatment. By contrast, when parathyroid hormone levels are higher, parathyroid sestamibi uptake remained unchanged. In such patients, parathyroidectomy or ethanol injection should be the best treatment. These glands would correspond to the most actively functioning glands; they would have a lesser expression of vitamin D receptors, rendering them refractory to medical treatment with calcitriol.     

Video-assisted thoracoscopic surgery as a first-line treatment for mediastinal parathyroid adenomas: strategic value of imaging

OBJECTIVE: To present first-line thoracic surgery made possible by localization studies in three patients with ectopic parathyroid adenomas. DESIGN AND METHODS: Three patients with ectopic parathyroid tissue in the mediastinum were examined by ultrasound, technetium-99m sestamibi scintigraphy, computed tomography (CT), and venous catheterization with measurement of parathyroid hormone. Without previous cervical exploration, video-assisted thoracic surgery (VATS) was used in all cases to avoid the need for thoracic open surgical procedures. RESULTS AND CONCLUSIONS: The mediastinal parathyroid glands were all detected at scintigraphy, and CT and venous catheterization were helpful in anatomic and functioning characterization. All pathologic glands were successfully resected, with only one minor complication. VATS can safely remove a deep mediastinal parathyroid adenoma and avoid more aggressive open approaches. In an experienced referral center, systematic and sophisticated imaging studies may accurately identify and localize rare ectopic parathyroid adenomas, and avoid cervical surgery.     

The role of colour Doppler ultrasonography in the preoperative localization of parathyroid adenomas

The aim of the present study was to evaluate the diagnostic accuracy and imaging patterns of colour Doppler ultrasonography (US) and compare it with grayscale US, 99m-Tc methoxyisobutylisonitrile (MIBI) scans, and combined US and MIBI scans in the preoperative diagnosis of parathyroid adenomas in patients with primary hyperparathyroidism (pHPT). From June 2007 to June 2011, 36 consecutive patients (seven men and 29 women) with pHPT underwent grayscale US, colour Doppler ultrasonography (CDUS), and 99m-Tc MIBI scans prior to parathyroidectomy with traditional unilateral neck dissection. All 36 patients with pHPT underwent parathyroidectomy at our university hospital. According to histopathology results, the sensitivity, specificity, and accuracy of MIBI and US scan were 88%, 94%, and 91%, and 70%, 100%, and 85%, respectively. The overall sensitivity and specificity of combined US and MIBI was 97% and 100% respectively. The overall sensitivity, specificity, and accuracy of CDUS in the correct diagnosis of parathyroid adenoma were 97%, 100%, and 98.6%, respectively. The sensitivity and specificity of US in the detection of parathyroid adenoma and differentiating it from other cervical masses reached up to 97% and 100%, respectively, by combining CDUS with grayscale evaluations of parathyroid adenoma.     

Localization of parathyroid tumours in the minimally invasive era: which technique should be chosen? Population-based analysis of 253 patients undergoing parathyroidectomy and factors affecting parathyroid gland detection

A series of 253 consecutive patients with proved primary hyperparathyroidism due to parathyroid tumours was reviewed. There were 68 (26.9%) men and 185 (73.1%) women, with a median age of 57 years (range 13-82 years). All patients, prior to successful parathyroidectomy, underwent one or more preoperative localization procedures such as: neck ultrasonography (US) in 191 (75.5%), (201)Tl/(99m)Tc-pertechnetate subtraction scintigraphy (TPS) in 144 (56.9%), CT scan in 92 (36.4%), (99m)Tc-sestamibi/(99m)Tc-pertechnetate subtraction scintigraphy (MPS) in 90 (35.6%), selective venous sampling (SVS) with parathyroid hormone (PTH) assay in 30 (11.9%), and magnetic resonance imaging (MRI) in 6 (2.4%) patients. The results were compared with operative and histological findings that showed 235 (92.9%) solitary parathyroid adenomas, 13 (5.1%) carcinomas and 5 (2.0%) double adenomas. Sensitivity and positive predictive value were 82.9% and 93.8% for US, 83.6% and 91.8% for TPS, 81.3% and 98.7% for CT scan, 85.1% and 96.1% for MPS, 65.4% and 80.9% for SVS, and 80.0% and 80.0% for MRI respectively. No different results (P=NS) were found using US, TPS, MPS or CT scan, whereas SVS and MRI sensitivity was lower (P<0.05). The combination of MPS and US was 94.0% sensitive (P<0.05) but when TPS, CT scan or MRI were also used overall sensitivity did not improve significantly (P=NS). In conclusion, MPS should be used as the starting preoperative localization procedure, while US and MPS together represent the most reliable noninvasive localization tool. If MPS and US are negative or not in agreement, further studies are not cost-effective and the patient should undergo bilateral neck exploration.     

Multimodality imaging of the parathyroid glands in primary hyperparathyroidism

Primary hyperparathyroidism is a common endocrine disorder, affecting approximately 1 in 500 women and 1 in 2,000 men. Surgical removal of the hyperfunctioning parathyroid gland is the primary curative treatment. The last decade has witnessed the development of minimally invasive parathyroidectomy, which is based on the fact that the vast majority of cases are caused by single adenomas. However, the success of this technique relies on accurate preoperative localisation of the parathyroid lesions. The imaging modalities used vary at different institutions according to local expertise and availability, but include high resolution ultrasound, radionuclide studies, computed tomography (CT) and magnetic resonance imaging (MRI). Ultrasound and 99mTc sestamibi scintigraphy, particularly when complemented by single photon emission computed tomography (SPECT), are currently the imaging techniques of choice for preoperative localisation of parathyroid adenomas; a combination of the two methods further improves the sensitivity and accuracy of detection. CT is less commonly used for preoperative localisation and usually reserved for cases of failed parathyroidectomy, for the detection of suspected ectopic glands. MRI appears to be useful in patients with persistent or recurrent hyperparathyroidism, who have previously undergone surgery. Cross-sectional imaging is also useful in cases where the findings at sonography and scintigraphy are discordant. SPECT/CT appears promising, but further studies are needed to evaluate its role in preoperative localisation.     

Technetium-99m tetrofosmin parathyroid imaging in patients with primary hyperparathyroidism

OBJECTIVE: To confirm the clinical significance of 99mTc-tetrofosmin imaging for the localization of hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism. METHODS: All patients were imaged with 99mTc-tetrofosmin at 10 minutes and 2 hours after radiotracer injection, and with ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI). The parathyroid/thyroid uptake ratio of 99mTc-tetrofosmin (P/T uptake ratio) was calculated. PATIENTS: Twenty patients with primary hyperparathyroidism were referred to our clinic, underwent surgical neck exploration or mediastinotomy and were diagnosed as having parathyroid adenoma. These patients were investigated for the preoperative localization by 99mTc-tetrofosmin scintigraphy. RESULTS: 99mTc-tetrofosmin imaging demonstrated focal uptake in 19 out of 20 patients with parathyroid adenoma. Two of the lesions were ectopic. US identified 17 parathyroid glands. CT and MRI initially detected 17 parathyroid glands. However, two additional parathyroid glands were localized on repeated CT and MRI in tandem with the results of the 99mTc-tetrofosmin imaging. Thus, the sensitivity and specificity of tetrofosmin imaging were 95% (19/20) and 95% (19/20); US, 85% (17/20) and 94% (16/17); initial CT, 85% (17/20) and 94% (16/17); and initial MRI, 88% (17/20) and 94% (16/17), respectively. The P/T uptake ratio at 2 hours after tetrofosmin injection was correlated with the serum concentration of intact PTH (rs=0.47, p<0.05) and the resected tumor weight (rs=0.53, p<0.05). CONCLUSION: 99mTc-tetrofosmin scintigraphy is useful for localization of parathyroid adenoma. Tetrofosmin uptake depends on the tumor weight and serum intact PTH levels.     

Preoperative evaluation of parathyroid lesions in patients with concomitant thyroid disease: role of high resolution ultrasonography and dual phase technetium 99m sestamibi scintigraphy

The aim of this study was to evaluate the sensitivity and usefulness of high resolution ultrasonography (US) and dual phase technetium-99m sestamibi (Tc-MIBI) scintigraphy in the preoperative localization of parathyroid lesions in patients with or without thyroid disease and to define the impact of the presence of thyroid disease on these methods. Preoperative US and scintigraphy were performed on 52 patients with primary hyperparathyroidism. Age, gender, preoperative parathyroid hormone level, serum calcium level, serum phosphate level, diameter, location, associated with thyroid abnormality, and results of parathyroid exploration were determined in all patients. The results of US and Tc-MIBI imaging were analyzed and compared with surgical and histopathologic findings. At surgery, 56 parathyroid lesions were found in 52 patients (9 men, 43 women), the parathyroid lesion was solitary (47 adenomas, two hyperplasias), in 2 patients double adenomas were present, in 1 patient three glands was affected by hyperplasia. Twenty-seven patients had concomitant thyroid disease. The overall sensitivity of US and Tc-MIBI scintigraphy was 84% and 73%, respectively. In patients without thyroid disease, the sensitivity of these techniques was 90% and 75%, respectively. In patients with thyroid disease, the sensitivity was 78% and 70%, respectively. In patients with thyroid disease, the combined sensitivity of these techniques was 89%. These results allow the conclusion that, in experienced hands, US is a highly sensitive technique. Especially in patients with no thyroid pathology and typical located gland, US alone should be used as a first step for preoperative localization of parathyroid lesions. When negative, Tc-MIBI scintigraphy is suggested. In patients with concomitant thyroid disease, the combination of US and Tc-MIBI scintigraphy represents a reliable localization technique.     

Localising imaging in secondary hyperparathyroidism

Preoperative imaging has proved its use successful in the localization of solitary parathyroid adenomas in patients with suspected primary hyperparathyroidism. However, due to multiglandular disease at presentation patients with renal hyperparathyroidism need to be analyzed separately, making the usefulness of imaging techniques controversial. Recently, improved methods of functional imaging like parathyroid scan with 99mTc-sestamibi or positron emission tomography, especially when combined with computed tomography, can provide additional quantitative and qualitative information that has yet to be assessed. Nuclear medicine procedures could prove useful not only in preoperative diagnosis, but also in the selection of medical or surgical therapeutic alternatives in secondary hyperparathyroidism patients. There is evidence that 99mTc-sestamibi uptake in parathyroid hyperplasia or adenoma is related to biochemical markers of parathyroid function. We are only beginning to identify the factors involved in radiotracer uptake by parathyroid cells and how it can be modulated to obtain more accurate results. This review analyzes the current use of non-invasive imaging modalities in patients with secondary hyperparathyroidism, taking into account the latest trends in the field combining anatomic and functional modalities and the relevant factors linked to radiotracer uptake in abnormal hyperfunctioning parathyroid glands.     

Hyperfunctioning parathyroid tumours in patients with thyroid nodules. Sensitivity and positive predictive value of high-resolution ultrasonography and 99mTc-sestamibi scintigraphy

A series of 112 consecutive patients with primary hyperparathyroidism who underwent both high-resolution neck ultrasonography (US) and 99mTc-sestamibi/99mTc-pertechnetate subtraction scintigraphy (SS) prior to successful parathyroidectomy was reviewed. There were 29 (25.9%) men and 83 (74.1%) women, with a median age of 58 years (range 13-78 years). Patients were divided into two groups, according to the preoperative US findings: group A (87 patients, 77.7%) without thyroid diseases, and group B (25 patients, 22.3%) with either multinodular goitre or a solitary nontoxic thyroid nodule. In group B patients partial or total thyroidectomy was also performed, according to the intraoperative findings and frozen-section examination results. Final histopathology showed 99 (88.4%) solitary parathyroid (PT) adenomas and 3 (2.7%) PT carcinomas, while 10 (8.9%) patients had a multiglandular disease. The sensitivity and positive predictive value (PPV) were (group A vs group B) 79.8% vs 70.8% (P=0.25) and 95.7% vs 94.4% (P=0.58) for US, and 83.3% vs 87.0% (P=0.47) and 95.9% vs 90.9% (P=0.32) for SS respectively. Better but similar (P=not significant) results were obtained in patients with solitary PT tumours: 81.5% vs 77.8% (US) and 85.0 vs 94.1% (SS) sensitivity; 97.1% vs 93.3% (US) and 95.8% vs 88.9% (SS) PPV. Overall, the combination of US and SS was 92.9% sensitive (group A=93.1%, group B=92.0%; P=0.55), and the PPV reached 100% in each group. In conclusion, in patients with primary hyperparathyroidism the results of both US and SS are independent of coexistent thyroid disease, especially in patients with solitary PT tumours.     

Disagreement between findings of 99mTc-MIBI and 99mTc-pertechnetate scintigraphy scans in patients with primary hyperparathyroidism

Sixty-two-year-old man was admitted to hospital for increased serum level of calcium (3.85 mmol/l) and incipient renal failure (urea 7.2 mmol/l, kreatinin 117 mumol/l). The reason of hypercalcaemia was intensive explored. Serum level of intact PTH was 383.6 pg/ml. We performed two-dimensional early and delayed (2 hours) scintigram after intravenous administration of 750 MBq 99mTc-sestamibi, i.e. double-phase technique. There was detected focus (diameter 20 mm) of increased sestamibi uptake with slow wash-out in distal part right thyroid lobe. Planar scintigraphy obtained after intravenous administration of 185 MBq 99mTc-pertechnetate detected focus of increased 99mTc-pertechnetate uptake in the same point too. Patient underwent right thyroid lobectomy. There was colloid nodular goiter. Under right thyroid lobe was detected spherical particle. This particle was ablated (diameter 20 mm, weight 4 gram). It was parathyroid adenoma. One month after ablation of parathyroid adenoma serum level of PTH was 23.1 pg/ml and serum level of calcium was 2.52 mmol/l. There was overlap of scintigraphy image of parathyroid adenoma under distal part of right thyroid lobe on 99mTc-sestamibi two-dimensional scintigram and scintigraphy image of hyperplastic node with increased activity in distal part of right thyroid lobe on 99mTc-pertechnetate two-dimensional scintigram.     

The role of ultrasound elastography in preoperative localization of parathyroid lesions: a new assisting method to preoperative parathyroid ultrasonography

Background After the definition of minimally invasive procedures, preoperative localization of parathyroid lesions is now crucial. False‐positive results up to 30% were reported by B‐mode grayscale ultrasonography (US) in localization of parathyroid lesions. Parathyroid adenomas are relatively stiff lesions. Ultrasound elastography (USE) can accurately evaluate tissue stiffness and might detect the stiff parathyroid lesions. Objective The aim of this study is to demonstrate whether USE can detect the level of the stiffness and help the preoperative localization of parathyroid lesions during parathyroid ultrasonography examination. Patients The patients who were candidates for parathyroidectomy were prospectively enrolled to this study and were evaluated by USE. Results Seventy‐two patients with 93 parathyroid lesions underwent parathyroidectomy. Sixty‐three patients including three multiple endocrine neoplasia type‐1 patients had primary hyperparathyroidism, three patients with chronic renal disease (CRD) had tertiary hyperparathyroidism, three patients with CRD and two renal transplanted patients had persistent secondary hyperparathyroidism. One patient was excluded. While all parathyroid adenomas exhibited high levels of stiffness (score 3 and 4), 17 (63%) out of 27 parathyroid hyperplasia lesions were shown to have significantly higher elasticity. The evaluation of median strain ratios of parathyroid lesions revealed that parathyroid adenomas demonstrated significantly higher levels of stiffness than hyperplasias (P ≤ 0·001). Conclusions This is the first study that evaluates the ultrasound elastographic features of parathyroid lesions. Parathyroid adenomas were shown to appear as stiff lesions, and half of the hyperplasias showed high elasticity. Parathyroid elastography is a novel technique to evaluate parathyroid lesions and might be a guide for surgeons to determine the type of operation to apply.     

Ultrasonography in detection of single and multiple abnormal parathyroid glands in primary hyperparathyroidism: comparison with radionuclide scintigraphy and surgery

BACKGROUND: Among the parathyroid imaging techniques, ultrasonography (USG) has the advantage of convenience, easy availability and low cost. OBJECTIVE: To study the role of USG in localization (side and/or site) of abnormal parathyroid glands in primary hyperparathyroidism (PHPT) and to compare with radionuclide scintigraphy and the 'gold standard', surgery. METHODS: Forty-six consecutive patients undergoing USG of the anterior neck for a diagnosis of PHPT in whom a nuclear scan (technetium-99m sestamibi and/or thallium-201/technetium-99m pertechnetate scintigraphy) was also performed, were studied. The results of imaging were independently interpreted and correlated with reference to surgical findings. RESULTS: Forty-six patients had 52 abnormal parathyroid glands on surgical exploration and surgery was successful in all but one. Forty-one patients had a single adenoma, four had multigland disease and one had a paraganglioma. USG correctly localized the abnormal gland in 30 (73%) and scintigraphy was positive in 40 (98%) out of 41 patients with a single adenoma as confirmed on surgical exploration. Scintigraphy showed a positive concordant test in all 30 patients with a single abnormal gland detected on USG and picked up 10 out of 11 abnormal glands where USG was negative. The sensitivity and positive predictive value of USG for detecting a single abnormal gland was 73% and 100%, respectively, whereas the sensitivity and positive predictive value for scintigraphy was 98%. In patients with multigland disease, USG missed 3 (30%) out of 10 and scintigraphy missed 6 (60%) out of 10 abnormal parathyroid glands as confirmed on surgical exploration (P < 0.05). However, in two patients who had ectopic parathyroid gland, both the modalities localized the lesion in one (paraganglioma), whereas in the other neither test was helpful (left retro-esophageal). CONCLUSION: USG is a convenient, affordable and useful modality to localize abnormal enlarged parathyroid glands in the majority of patients with PHPT. However, when USG is negative, scintigraphy is complementary to it.     

Parathyroid localization by 201Tl-99mTc subtraction scintigraphy: results in secondary hyperparathyroidism

Subtraction scintigraphy with 201Tl and 99mTc for parathyroid localization was performed preoperatively in 13 patients with chronic renal failure and secondary hyperparathyroidism. Twenty of the 37 examined pathological glands were predicted correctly (sensitivity 54%). In 3 patients with recurrent hyperparathyroidism after surgery all pathological glands found at second operation had been detected correctly by subtraction scintigraphy. We conclude that this localization method has a limited value when used prior to first neck exploration in secondary hyperparathyroidism. In persistent hyperparathyroidism after surgery it may play a useful role in localizing missed and ectopic glands.     

Nouveautés thérapeutiques dans l'hyperparathyroïdie primitive

Modern imaging techniques such as ultrasonography and sestamibi scintigraphy (alone or combined with computed-tomography scanning) are useful for the preoperative localisation of a single adenoma in most cases. In such patients, minimally invasive parathyroidectomy may be considered, either by unilateral approach and local anaesthesia or by a video-assisted procedure. The success rate, assessed by perioperative rapid PTH assays, is of 84-90%, reaching 97% after conversion to conventional parathyroidectomy. Thoracoscopic resection may be considered for mediastinal adenomas. Specialized surgical teams have developed hypnotic approaches, locoregional anaesthesia or ultrasound-guided percutaneous ethanol injection. Medical treatment should soon include those calcimimetic drugs that are currently under evaluation. Anti-PTH immunization has shown efficacy in managing the rare cases of parathyroid cancer.     

Ultrasonographic features of intrathyroidal parathyroid adenoma causing primary hyperparathyroidism

Preoperative localization study is difficult in patients with primary hyperparathyroidism (PHPT) caused by intrathyroidal parathyroid adenoma. The objective of this study was to evaluate the usefulness of ultrasonography (US) in the diagnosis of intrathyroidal parathyroid adenoma. Between January 2004 and December 2009, seven of 373 patients who underwent parathyroidectomy because of PHPT in our hospital were found to have intrathyroidal parathyroid adenoma. The ultrasonographic features of intrathyroidal parathyroid adenoma were examined retrospectively. The most characteristic feature of intrathyroidal parathyroid adenoma was a hyperechoic line on the ventral surface of the parathyroid gland. A hyperechoic line was clearly detected even in small adenomas in which feeding vessels could not be detected on color Doppler sonography. In comparison with feeding vessels, a hyperechoic line was frequently detected in normally located parathyroid adenoma. (99m)Tc-sestamibi (MIBI) scintigraphy and computed tomography (CT) could show parathyroid adenoma in the intrathyroidal position in only three of five and in only one of three patients examined, respectively. Since a hyperechoic line is characteristic of parathyroid adenoma, an intrathyroidal parathyroid adenoma could be suspected by only non-invasive US.     

Reduced p18INK4c, p21CIP1/WAF1 and p27KIP1 mRNA levels in tumours of primary and secondary hyperparathyroidism

OBJECTIVE: Hyperparathyroidism (HPT) refers to states of excessive production of parathyroid hormone (PTH). The eukaryotic cell cycle is driven forward by cyclins and their cyclin-dependent kinase (CDK) partners. Cyclin-dependent kinase inhibitors (CKIs), which generally inhibit cell cycle progression, modulate the activity of cyclin-CDK complexes. DESIGN: In order to quantify the expression of the CKI genes p18, p21, and p27 semiquantitative RT-PCR with mRNA specific-primers was performed on four normal parathyroid biopsies, 31 parathyroid adenomas of primary HPT and 13 hyperplastic glands from uraemic patients with secondary HPT. PATIENTS: Parathyroid adenomas and secondary hyperplastic glands were obtained from 31 and 13 randomly selected patients undergoing parathyroidectomy in the clinical routine, respectively. Four normal parathyroid gland biopsies were obtained at surgery for pHPT or from normocalcemic patients undergoing thyroidectomy for goitre. RESULTS: The relative p27 expression (p27/GAPDH) was significantly reduced in parathyroid adenomas compared to normal parathyroid gland biopsies. Furthermore, 42% and 53% of the parathyroid adenomas displayed undetectable p18 and p21 expression levels, respectively. All 13 adenomas that lacked p18 expression showed undetectable p21 expression. The p18 expression was significantly lower in tumours of uraemic sHPT as compared to normal parathyroids and an undetectable expression level was observed for p21 and p27 in 61% and 53%, respectively. CONCLUSION: Parathyroid adenomas and secondary hyperplastic glands exhibit aberrant reduced expression of the CKIs p18, p21, and p27. This suggests that deranged collaboration of different CKIs may contribute to the development of both primary and secondary HPT.