Proven Parathyroid Adenomas Research Articles

18F-fluorocholine PET/CT semi-quantitative analysis in patients affected by primary hyperparathyroidism: a comparison between laboratory and functional data.

This retrospective study aims to establish 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) performance in finding hyperfunctioning parathyroid glands, analyze a potential role for semi-quantitative PET parameters and assess factors that may influence PET/CT outcome. Forty patients with suspect primary hyperparathyroidism (pHPT) and negative/equivocal conventional imaging underwent FCH-PET/CT in our Institution. For every lesion, visual and semi-quantitative analyses were performed on PET/CT images. In qualitative analysis, a lesion was considered positive if a clear focus of uptake, significantly higher than normal thyroid tissue, was identifiable. Ectopic focal uptake was also regarded as positive PET result. Lesion SUVMax was measured by assigning a spheric VOI to the suspect area of uptake. Thyroid SUVMean was assessed by placing a spheric VOI inside the contralateral thyroid lobe, and SUVratio was calculated using this background region. All patients were subsequently submitted to surgery and histopathologic workup. Sensitivity, positive predictive value (PPV) and accuracy were calculated based on histopathologic reports for every lesion. Pearson's test was used to assess a correlation between laboratory and histopathologic features with SUVr. Four out of the 40 patients who underwent surgery for pHPT had more than one histologic proven unhealthy parathyroid and three had papillary thyroid cancer (PTC). A total of 48 lesions were analyzed. We found 42/48 lesions (87.5%) to have true-positive uptake, whereas three lesions (6.7%) had false-positive uptake (PTC). Three histologic proven parathyroid adenomas showed no uptake (6.7%); the sensitivity/PPV were 93.3% and accuracy was 87,8%. Pearson's test showed a significant correlation between PTH values and parathyroid size with SUVr values (r = 0.56 and 0.55, respectively, p < 0.01 for both features). As stated in recent literature, we observed excellent diagnostic sensitivity of FCH-PET/CT in patients with pHPT, providing surgeons a fine tool to optimize treatment. More studies are needed to improve the evaluability of semi-quantitative parameters towards a further improvement of diagnostic accuracy.

The role of gamma probe activity counts in minimally invasive parathyroidectomy. Preliminary results.

The benefit of preoperative gamma probe in the diagnosis of adenoma in patients with histopathologically proven parathyroid (PT) adenomas was examined. 20 patients with positive (99m)Tc MIBI uptake in PT scintigraphy with primary hyperparathyroidism were enrolled in this study. 740 MBq (99m)Tc MIBI were injected 3 h before operation. Counts of four PT regions were obtained with gamma probe before surgery in the operation room. All suspected PT adenomas were resected and histopathologically diagnosed as adenomas. We also obtained counts of the resection region and the resected adenoma with gamma probe after the parathyroidectomy. Preoperative counts of adenoma bearing regions (ABR), non-adenoma bearing regions (NABR), postoperative resection region (PRR), resected adenoma counts (RA) were registered. Statistical analysis was performed by Wilcoxon rank test. The mean counts of ABR, NABR, the PRR and RA were 462 +/- 106, 230 +/- 66, 164 +/- 42, 374 +/- 87, respectively. The mean counts from ABR were twofold higher than those of NABR. The PRR mean counts decreased by 64% when compared to the mean counts of ABR and by 55% when compared to the mean counts of RA. The differences in mean counts of ABR and NABR, PRR and ABR, PRR and RA (p <0.01) turned out as statistically significant. According to our preliminary results, the region with the highest counts is at least 2 +/- 0,4 times higher than the mean of the other three PT regions. Thus, it seems to be significant for PT adenoma. Resection of adenoma may be accepted as successful, if the count of ABR decreased more than 64% with decreased postoperative parathormone levels. This technique should not yet be applied instead of parathormone measurement or frozen technique. But it may replace the frozen technique used for confirmation of the diagnosis during the operation in the future.

Variable sonographic spectrum of parathyroid adenoma with a novel ultrasound finding: dual concentric echo sign.

To review the detailed gray-scale and Doppler ultrasonography features of histologically proven parathyroid adenomas (PAs) evaluated with high-end ultrasonography devices and to present a novel ultrasonography finding called the dual concentric echo sign in PA with histopathologic correlation which was encountered during detailed analysis. Fifty-six PAs with histopathological result were enrolled. The longest dimension, shape, distance to skin surface, internal echo and Doppler US features obtained with high-end US devices were evaluated. PAs had variable range of shape including oval, irregular, fusiform, lobulated, crescent-shaped, and nodular configuration. In nine patients the lesions were shown to have cystic components and calcifications were seen in four cases. Dual concentric echo sign was detected in 18% PAs. Histological reevaluation of this subgroup demonstrated significantly increased edema (p<0.01), and ectatic vessels (p=0.02) in the central part of the lesion compared to the rest of the PAs. The results of the study led to the conclusion that PAs have variable gray-scale and Doppler findings. Typical sonographic features like ovoid shape, homogeneously hypoechoic pattern may not be present in all PAs. Dual concentric echo sign which is a novel sonographic pattern may be suggestive of a PA.

The role of gamma probe activity counts in minimally invasive parathyroidectomy

Summary Aim: The benefit of preoperative gamma probe in the diagnosis of adenoma in patients with histopathologically proven parathyroid (PT) adenomas was examined. Patients, material, methods: 20 patients with positive 99mTc MIBI uptake in PT scintigraphy with primary hyper-parathyroidism were enrolled in this study. 740 MBq 99mTc MIBI were injected 3 h before operation. Counts of four PT regions were obtained with gamma probe before surgery in the operation room. All suspected PT adenomas were resected and histopathologically diagnosed as adenomas. We also obtained counts of the resection region and the resected adenoma with gamma probe after the parathyroidectomy. Preoperative counts of adenoma bearing regions (ABR), non-adenoma bearing regions (NABR), postoperative resection region (PRR), resected adenoma counts (RA) were registered. Statistical analysis was performed by Wilcoxon rank test. Results: The mean counts of ABR, NABR, the PRR and RA were 462 ± 106, 230 ± 66, 164 ± 42, 374 ± 87, respectively. The mean counts from ABR were twofold higher than those of NABR. The PRR mean counts decreased by 64% when compared to the mean counts of ABR and by 55% when compared to the mean counts of RA. The differences in mean counts of ABR and NABR, PRR and ABR, PRR and RA (p &lt;0.01) turned out as statistically significant. Discussion: According to our preliminary results, the region with the highest counts is at least 2 ± 0,4 times higher than the mean of the other three PT regions. Thus, it seems to be significant for PT adenoma. Resection of adenoma may be accepted as successful, if the count of ABR decreased more than 64% with decreased postoperative parathormone levels. Conclusion: This technique should not yet be applied instead of parathormone measurement or frozen technique. But it may replace the frozen technique used for confirmation of the diagnosis during the operation in the future.

Noninvasive localization of parathyroid adenomas: A comparison of X-ray computerized tomography, ultrasound, scintigraphy and MRI

Thirty-two (32) patients with primary hyperparathyroidism (17 with prior localization surgery, 15 without) were studied by a combination of computed tomography (CT), ultrasound (US), nuclear medicine (NM), and magnetic resonance imaging (MRI) for parathyroid adenoma localization. The sensitivity and true-positive ratio of each imaging technique and various combinations of techniques were evaluated. Of the 28 proven parathyroid adenomas (27 by surgery, 1 by digital subtraction angiography), 24 were imaged by two techniques, 19 by three techniques, and 10 by all four imaging techniques. The sensitivities were NM (65%), CT (76%), US (77%), and MRI (81%). The differences between true-positive ratios of 82%, 64%, 71%, and 77%, respectively, were not statistically significant. If multiple techniques were considered as a single test (i.e., a positive localization requires two or more tests to be positive at the same location), then sensitivity for a two-study combination was 79% and true-positive ratio 86%. Three techniques showed a sensitivity of 63% and a true-positive ratio of 92%, four modalities 40% and 100%, respectively. There was no significant difference in the various combinations of techniques employed (e.g., CT and US, US and MR, NM and MR, etc.). Thus, there appears to be an advantage in performing multiple techniques (regardless of which combination is selected) until two tests are positive at the same location.

The Importance of Phosphate in Regulating Plasma 1,25-(OH)2-Vitamin D Levels in Humans: Studies in Healthy Subjects, in Calcium-Stone Formers and in Patients with Primary Hyperparathyroidism*

We observed that plasma 1,25-(OH)2-D concentrations average 87 +/- 30 SD pmol/l in 48 healthy adults without a personal or family history of kidney stones. Plasma 1,25-(OH)2-D concentrations were significantly elevated among 26 patients with recurrent calcium-containing renal stones and hypophosphatemia: 150 +/- 74 pmol/l; P less than 0.001, and among 9 patients with proven parathyroid adenoma and hypophosphatemia: 200 +/- 54 pmol/l; P less than 0.001. Plasma 1,25-(OH)2-D levels in these 3 groups were inversely correlated with serum phosphate concentration: plasma 1,25-(OH)2-D, pmol/l = 282 - 141 X serum PO4, mmol/l; r = 0.51; P less than 0.001. During dietary PO4 deprivation lasting 11 to 16 days in 10 healthy women, serum PO4 fell and plasma 1,25-(OH)2-D concentrations rose whereas in 8 healthy men neither serum PO4 nor 1,25-(OH)2-D concentrations changed. The change from control in plasma 1,25-(OH)2-D levels were correlated with the change from control in serum PO4 concentrations: delta1,25-(OH)2-D, pmol/l = 1 - 82 X delta serum PO4 mmol/l; r = 0.59; P less than 0.01. We conclude that reductions in serum PO4 concentrations, either directly or indirectly, stimulate renal synthesis of 1,25-(OH)2-D in humans.

Needle Bone Biopsy in

Results of diagnostic needle bone biopsies in 25 patients subsequently undergoing neck exploration for parathyroid disease are reported. Histologic changes believed to represent hyperparathyroidism in bone biopsy specimens included evidence of (1) increased osteoblastic activity; (2) increased osteoid formation; and (3) excessive osteoclastic activity. Such changes were seen in 23 of 25 biopsies. The results of two biopsies were negative. A positive correlation between pathologic findings in bone and surgically proven primary hyperparathyroidism was noted in 20 of 25 patients. Nine of the patients with abnormal biopsies had hyperparathyroidism, despite normal roentgenograms and alkaline phosphatase levels. Explanations accounting for abnormal biopsies in three patients with negative results for neck exploration were available. Two patients with proven parathyroid adenoma had negative results for bone biopsies. With proper interpretation, needle bone biopsy is a useful tool for evaluation of primary hyperparathyroidism.

Glandula in Glandula: The Intrathyroid Parathyroid

Three cases are reported of proven parathyroid adenoma located in a lobe of the thyroid. This situation must always be borne in mind when searching for the parathyroid in the neck, and the excision of a lobe of the thyroid may save the patient from an unnecessary sternotomy and mediastinal exploration.

The Value of the Selenomethionine Se 75 Scan in Preoperative Localization of Parathyroid Adenomas

The selenomethionine Se 75 scan was performed in 42 patients with a clinical diagnosis of hyperparathyroidism. The scan correctly localized the abnormal gland in 13 of 23 patients with proven parathyroid adenoma. The parathyroid scan was not helpful in seven patients with parathyroid hyperplasia. Size was the most important factor contributing to visualization of parathyroid adenomas. Adenomas larger than 2 gm were consistently visualized while those weighing less than 1 gm were commonly not detected by the scan. High background over the mediastinum precludes the possibility of detecting most mediastinal adenomas by this technique. The value of the selenomethionine Se 75 parathyroid scan is thus limited in patients with small adenomas or hyperplastic glands and in patients with adenomas or hyperplastic glands lying deep in the thorax.