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.     

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.     

Brown tumor of the sternum--a potential cause of false-positive result on parathyroid scintigraphy with Tc-99m sestamibi

Parathyroid scintigraphies have been used to detect pathological parathyroid glands either before as well as after the parathyroid resection surgery in patients with hyperparathyroidism. Although this test presents high specificity for detection of increased parathyroid glands, there exist causes of false positive results. In the present article, we report a case of a renal transplanted patient, with multiple lytic lesions on pelvic bones reported as brown tumors, who presented a focal uptake in the anterior portion of the superior mediastinum on Tc-99m sestamibi scintigraphy. This focal uptake, initially thought to be an ectopic parathyroid gland, after a more detailed analysis and the performance of other imaging diagnostic tests was demonstrated to be a brown tumor of the sternum.     

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.     

Diagnosis of recurrent secondary hyperparathyroidism using double-phase 99m-Tc-MIBI gammagraphy after total parathyroidectomy with autotransplantation

We present two cases of uremic patients with poor medical control of their secondary hyperparathyroidism. They had to undergo surgery to control symptoms. A total parathyroidectomy with autotransplant in the forearm muscles was performed. After a symptom-free period, both showed a recurrence of their hyperparathyroidism. A double phase 99mTc-MIBI scintigraphy was essential in order to correctly locate hypertrophic parathyroid gland. In one case there was a cervical recurrence and in the second patient hyperplasia in a forearm gland autotransplant was found. Both patients remained asymptomatic with medication during their follow up.     

Noninvasive localization procedures in ectopic hyperfunctioning parathyroid tumors

In primary hyperparathyroidism (pHPT), parathyroidectomy is the treatment of choice, but anatomic variations of ectopic glands may cause surgical failure. Reliable preoperative noninvasive localization procedures would have a positive impact on the operative time and increase recovery rate. We retrospectively evaluated 186 patients with pHPT who were studied before successful parathyroidectomy by double tracer scintigraphy (99mTc-pertechnetate+201TI chloride or 99mTc-pertechnetate +99mTc-sestamibi, 160 patients), ultrasonography (148 patients) and computerized tomography (CT) scan (92 patients). During bilateral neck exploration, 159 (85.5%) single adenomas, 6 (3.2%) parathyroid carcinomas, and 3 (1.6%) double adenomas were found. Moreover, 18 (9.7%) patients had diffuse chief cells parathyroid hyperplasia. Removed parathyroid glands were in ectopic sites in 41 (22.0%) cases, mainly localized in the upper mediastinum or behind the esophagus. The overall sensitivity was 83.5 and 85.2% for 99mTc-pertechnetate+201TI chloride and 99mTc-pertechnetate+99mTc-sestamibi scintigraphy respectively, 80.4% for CT scan and 81.1% for ultrasonography. In patients with ectopic glands, sensitivity was 81.2, 79.5, 73.3 and 81.6% respectively. In 36 out of 41 patients with ectopic glands in whom the removed parathyroids were correctly localized, mean operative time was 95 min, and in 5 patients without preoperative localization it was 260 min. In conclusion, in pHPT, preoperative localization of an enlarged parathyroid is helpful, especially in ectopic adenomas and in anatomic variations in location, and it has been proved to reduce operative time and morbidity rate.     

Computerized axial tomography in the diagnosis and management of thyroid and parathyroid disorders

Computerized axial tomography (CAT) was used to study 39 patients with known thyroid disease and 14 patients with primary hyperparathyroidism. In all, CAT was performed only when information that was required for diagnosis or therapy was not available from other less expensive techniques. The greatest value was found in the evaluation of cryptic symptoms or structures in the neck after surgery for thyroid cancer, the assessment of the extent of thyroid cancer, the localization of aberrant thyroid tissue, the etiology of unexplained recurrent laryngeal nerve paralysis and the identification and delineation of mediastinal goiter. In six of 14 patients undergoing neck exploration for primary hyperparathyroidism CAT correctly localized the site of the enlarged parathyroid glands including one mediastinal parathyroid adenoma and one patient with two parathyroid adenomas.     

Parathyroid localization

Twenty-nine consecutive patients with suspected primary hyperparathyroidism were examined preoperatively using ultrasound, sonographically guided fine needle aspiration, and aspirate immunostaining for PTH. In 25 patients, localization of enlarged parathyroid glands was successful. In 2 patients, the tumors were located retrosternally and, thus, could not be detected by ultrasound. One patient had a multinodular goiter which impeded localization. In 1 patient with renal osteodystrophy, 2 enlarged parathyroid glands in the neck were not visualized preoperatively. Cytology was not diagnostic, although some cytological features were suggestive of parathyroid cells. Immunostaining of the aspirated smears for PTH, however, correctly diagnosed all preoperatively localized lesions. Ultrasound should be the routine procedure of choice for preoperative localization of abnormal parathyroid glands in primary hyperparathyroidism. Fine needle aspiration and immunocytochemistry can supply confirmation, if necessary.     

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.     

Discordant results in Tc-99m tetrofosmin and Tc-99m sestamibi parathyroid scintigraphies

Parathyroid scintigraphies have been used to detect pathological parathyroid glands either before as well as after the parathyroid resection surgery in patients with hyperparathyroidism. One of the most utilized techniques to perform the studies is the double-phase images with Tc-99m sestamibi, which has been shown to be very accurate in the localization of enlarged parathyroid glands. Similar to Tc-99m sestamibi, Tc-99m tetrofosmin is a radiopharmaceutical initially developed to perform myocardial perfusion study that has been used to perform parathyroid scintigraphies. Although most of the papers suggest that the overall sensitivities of both radiopharmaceuticals are similar, there are some papers questioning the accuracy of Tc-99m tetrofosmin to detect abnormal parathyroid glands. In the present article, we report a case with discordant results by both methods.     

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.     

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.     

Primary hyperparathyroidism. A surgical perspective

Primary hyperparathyroidism is a common disorder and one that can usually (approximately 95%) be successfully treated by parathyroidectomy. PTH assays have become quite accurate for confirming the diagnosis. In patients with malignancy-associated hypercalcemia, parathyroid-like protein levels are usually increased, and radioimmunoassays being developed to quantitate serum levels of this protein will make the diagnosis easier. Treatment for a parathyroid adenoma is removal of the tumor and identification of the normal parathyroid glands. Treatment for primary or secondary hyperplasia is usually subtotal parathyroidectomy. Recurrent hyperparathyroidism is uncommon, except in patients with familial hyperparathyroidism, MEN-1 parathyroid carcinoma, or renal failure and secondary hyperparathyroidism. Persistent hyperparathyroidism is more common and is usually due to surgeon inexperience, but it is also caused by ectopically situated parathyroid glands, multiple abnormal parathyroid glands, or supranumerary parathyroid glands. Preoperative localization studies using ultrasound, thallium-technetium scanning, MRI, or CT scanning are reliable in patients with solitary parathyroid adenomas, but often fail to detect all of the abnormal parathyroid tissue in patients with multiple abnormal parathyroid glands. Intraoperative use of urinary cyclic AMP assays and rapid PTH assays have recently been used experimentally during parathyroid explorations to determine whether all hyperfunctioning parathyroid tissue has been removed, but these methods are not yet reliable or fast enough to be generally accepted. Most patients with primary hyperparathyroidism who are successfully treated by parathyroidectomy experience psychological, clinical, and metabolic benefits.     

Coincidence of hot thyroid nodules and primary hyperparathyroidism.

Hyperthyroidism is frequently associated with hypercalcemia, which usually subsides after successful treatment of hyperthyroidism. Moreover, thyroid nodules are frequently detected by preoperative thyroid ultrasound in patients with primary hyperparathyroidism. Sensitised by the observation of a patient with coexisting hyperthyroidism and hyperparathyroidism we prospectively evaluated thyroid nodules in euthyroid patients with hyperparathyroidism by thyroid scintigraphy. Whereas the first patient with hyperparathyroidism was hyperthyroid the subsequent four patients with hyperparathyroidism and thyroid nodules had normal fT3 and fT4. Two patients had hypercalcemia and nephroureterolithiasis. Three patients suffered from hypercalcemia and bone pain due to osteoporosis. In the hyperthyroid patient hypercalcemia persisted after euthyroidism was achieved intact parathyroid hormone was found to be elevated. Subsequently, thyroid nodules, detected by preoperative ultrasound in four euthyroid patients with primary hyperparathyroidism, were identified as compensated hot nodules by thyroid scintigraphy. All patients underwent combined subtotal thyroidectomy and parathyroid resection. Histology showed hyperplastic parathyroid glands in one patient and a single parathyroid adenoma in four cases. Postoperatively calcium and PTH levels returned to normal and TSH levels increased in all patients. Persistence of hypercalcemia after successful treatment of hyperthyroidism should be reason for the determination of parathyroid hormone. Thyroid nodules detected by preoperative ultrasound in patients with hyperparathyroidism living in areas of iodine deficiency should be further evaluated by scintigraphy even if TSH is normal. In the case of hot thyroid nodules both parathyroid and partial thyroid resection should be performed.     

原发性甲状旁腺功能亢进的核素定位诊断

应了~（99m）Tc-MIBI进行了甲状旁腺显像,并对方法学进行了探讨。10例患者经临床、生化确诊为原发甲旁亢,但均未触及增大的甲状旁腺或甲状腺。其中7例在应用~（99m）Tc-MIBI和~（99m）Tc两种示踪剂分别进行甲状旁腺显像和甲状腺显像,3例仅用~（99m）Tc-MIBI,但在显像过程中给予了过氯酸盐。在静泳注射~（99m）Tc-MIBI后不同时间采集图象并选用产P/T值（甲状旁腺计数/甲状腺计数）做参数,以了解示踪剂的代谢及确定最佳显像时间。10例患者经手术共摘除12枚肿大的甲状旁腺,病理证实10枚为甲状旁腺腺瘤,2枝为甲状旁腺增生,B超检查9例中发现2枚腺瘤,CT检查8例共发现3枚腺瘤,核素显像10例患者各发现腺瘤一个,其阳性部位与手术所见完全吻合。尽管例数较少,但初步看,此方法简便、准确,对于原发甲旁亢的定位诊断确有临床价值。     

Results of bone scintigraphy,densitometry and radiography in secondary hyperparathyroidism in patients with chronic renal failure

Secondary hyperparathyroidism occurs frequently in patients with chronic renal failure (CRF). Cardinal manifestations in patients with secondary hyperparathyroidism involve also skeletal changes. Hence the aims of our studies were detailed investigations of bones using isotope scintigraphy (99mTc-MDP), densitometry (DEXA-Lunar) and radiography, in a group of 34 patients with advanced secondary hyperparathyroidism with very high PTH serum concentrations. Bone mineral density of radius amounted to 74.14 +/- 14%, and 29 cases had osteoporosis, and 5 cases osteopenia. Bone mineral density of vertebral bodies was 85.6 +/- 10.5% was within osteopenia range in 16 cases, osteoporosis in 11 cases and was normal in 6 cases. Bone scintigraphy revealed: excessive tracer uptake in cranial vault, mandible, spine and lateral parts of the sacral bone. Tracer accumulation was decreased in soft tissues and absent in kidneys. Roentgen studies revealed changes typical to secondary hyperparathyroidism: acroosteolysis in 60% of cases, subperiosteal resorption in 43% of cases, calcifications in 20% of cases, cortical fibrosis in 35% of cases and osteoporosis in 85% of cases. CONCLUSIONS: 1. Bone mineral density is markly decreased in the radius and to a lower extent in the vertebral bodies, hence DEXA studies of radius are most appropriate for evaluation of mineral bone density. The differences in BMD are characteristic of hyperparathyroidism, both primary and secondary. 2. In most patients bone scintigraphy shows characteristic abnormalities, thus scintigraphy is helpful in the diagnosis of advanced secondary hyperparathyroidism. 3. In x-ray studies osteoporosis is frequently observed, other signs of secondary hyperparathyroidism are not so common and appear in later stage of disease than decreased bone mineral density in densitometry.     

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.     

Surgical treatment of primary hyperparathyroidism: from bilateral neck exploration to minimally invasive surgery

The human parathyroid glands, first described by Sandstr?m in 1880, attracted interest because they were subject to inadvertent removal or ischemic injury during radical thyroid surgery. That this caused metabolic derangements was not known until many years later. Following on Kocher's studies, research continued to improve techniques sparing the parathyroids during thyroid surgery but without developing parathyroid surgery as such. For over a century, the lack of suitable surgical instruments, accurate preoperative localizing imaging techniques, and reliable laboratory tests hindered the evolution of parathyroid surgery, relegating it a marginal existence. Only after 1930, when it became clear that hyperparathyroidism is caused by an increased production of parathyroid hormone (PTH) by overactive parathyroid glands in the neck and/or the mediastinum, could parathyroid surgery, which shares a similar approach with thyroid surgery, be developed for treating hyperparathyroidism. The aim of parathyroid surgery is to cure hyperparathyroidism. Until advanced surgical and laboratory diagnostic technologies became available, concern about the risk of failure led surgeons to search all four glands by bilateral neck exploration, which proved unnecessary in 80% of cases. Recent years have seen parathyroid surgery evolve with the introduction of more efficacious preoperative localization imaging techniques and the use of rapid intraoperative parathormone assay, so that parathyroid surgery is now more selective and can be performed as a minimally invasive procedure in some cases.     

Parathyroid incidentaloma. Literature review about three case reports

Background

Parathyroid incidentaloma is not a well-known entity. The aim of this study was to show its incidence and to discuss its management.

Methods

This was a prospective study analyzing cases of enlarged parathyroid glands discovered during thyroid surgery. The records of patients with parathyroid incidentaloma were reviewed. We also reviewed all cases of primary hyperparathyroidism (HPTPs) operated during the same period for comparison.

Results

Three cases of enlarged parathyroid were found. No clinical or biochemical features led us to suspect hyperparathyroidism before surgery, but a macroscopically enlarged parathyroid gland was discovered during the dissection and was removed in all three patients.

Conclusions

Enlarged parathyroid glands discovered at the time of surgery may represent an early pathological stage responsible for overt primary hyperparathyroidism. In absence of major risk for recurrent nerve palsy, we recommend removal of any enlarged parathyroid discovered during neck surgery in order to avoid the risks of future surgical procedures, preserving in the same time at least one normal parathyroid gland.