Preoperative localization and minimally invasive management of primary hyperparathyroidism concomitant with thyroid disease

Differentiating thyroid nodules parathyroid lesions using 2D-shear-wave elastography: a novel approach for enhanced diagnostic accuracy

Differentiating between thyroid and parathyroid lesions by means of ultrasound can be a challenge in some cases. This study explores the diagnostic efficacy of bidimensional shear wave elastography planewave ultrasound (2D SWE PLUS) as an auxiliary technique in distinguishing these superficial structures. We evaluated 86 cases, presenting with concurrent thyroid nodules and hyperparathyroidism, through conventional ultrasound and 2D SWE PLUS, employing an Aixplorer Supersonic Mach30 with a 5-18 MHz linear probe. Statistically significant differences were observed for the elasticity index (EI) between parathyroid and normal thyroid tissue (p<0.0001, U=291), and between parathyroid lesions and thyroid nodules (p<0.0001, U=248.5). An area under the curve (AUC) of 0.961, with an optimal cut-off value of ≤8.9 kPa, was established to effectively distinguish parathyroid tissue from normal thyroid tissue (sensitivity of 91.9%; specificity of 97.5%). Furthermore, an AUC of 0.963 and an optimal cut-off of 9.24 kPa (sensitivity of 94.2%, specificity of 91.1%) were determined for parathyroid vs thyroid lesions. Elasticity values were significantly elevated in the cancer group compared to benign thyroid nodules (p<0.0001). Our findings suggest that 2D SWE PLUS is an effective tool in differentiating between thyroid nodules and parathyroid lesions, enhancing diagnostic performance in neck ultrasonography.

Impact of autoimmune thyroiditis on primary hyperparathyroidism

Aim. Primary hyperparathyroidism (PHPT) often coexists with thyroid diseases. Current guidelines advise preoperative ultrasound (US) examination of the thyroid gland for thyroid nodular disease or concomitant malignancy but not evaluation for autoimmune thyroiditis (AIT). The impact of autoimmune thyroiditis on the clinical presentation and intraoperative course of PHPT is not clear. Material and methods. We retrospectively assessed the medical records of 21 patients with PHPT who underwent parathyroidectomy. Clinical, biochemical, ultrasonographic and intraoperative data were evaluated. Results. There was a longer duration of parathyroidectomy in patients with AIT than in those without (113.3 min vs. 93.9 min, P=0.03). A lower rate of kidney stones was noted in patients with autoimmune thyroiditis (44.4% vs. 0%, P=0.03). Patients with AIT were more symptomatic, but this was not significant. There was no difference between the two groups in the prevalence of osteoporosis or thyroid nodular disease. Conclusions. A significantly longer duration of parathyroidectomy was seen in PHPT patients with AIT. Patients with PHPT undergoing surgery should be investigated for autoimmune thyroiditis, as this may affect surgical planning.

A case of normocalcemic primary hyperparathyroidism presenting with a mass in the oral cavity and accompanying incidental papillary thyroid carcinoma

Hyperparathyroidism (HPT) is an endocrine disorder characterized by high secretion of parathyroid hormone. Brown tumor is one of the skeletal manifestations of HPT. Its overall prevalence is low (about 0.1%). Involvement of facial bones is extremely rare. The mandible is involved in 4.5% of cases. Primary HPT (PHPT)with vitamin D deficiency worsens the clinical course. Parathyroid adenoma is detected in ectopic places with a rate of 8.5%. 0.2% is intrathyroidal, 2% is located in different neck regions, 4.1% is in the upper mediastinum, and 2.2% is in the lower mediastinum. The prevalence of papillary thyroid cancer (PTC) in PHPT patients has been reported to range from 2% to 15%. In the literature, incidentally detected papillary thyroid cancer in patients with hyperparathyroidism was detected in patients who underwent total thyroidectomy associated with intrathyroidal parathyroid adenoma. In this article, we present a case of incidental papillary thyroid carcinoma with ectopic parathyroid adenoma accompanied by severe vitamin D, and diagnosed during accompanying surgery following a brown tumor was considered after primary hyperparathyroidism was detected. However, the patient was admitted with a mass in the oral cavity, diagnosed before as a pyogenic granuloma with a delayed diagnosis without considering brown tumor because it was normocalcemic. It is the first case in the literature of papillary thyroid carcinoma detected incidentally with ectopic parathyroid adenoma in the thyrothymic region.

Differences in Clinicopathological Characteristics of Papillary Thyroid Carcinoma between Symptomatic and Asymptomatic Patients with Primary Hyperparathyroidism

BACKGROUND

Popularization of cervical ultrasound led to higher detection of papillary thyroid carcinoma (PTC) and primary hyperparathyroidism (PHPT), as well as increasing percentage of asymptomatic PHPT in China. Although the coexistence of PTC and PHPT has been reported, it is unknown whether the clinicopathological features of PTC differ between asymptomatic and symptomatic PHPT patients.

METHODS

We retrospectively reviewed the medical records of 304 PHPT patients treated in our hospital between January 2009 and July 2020, including 217 females and 87 males with the average age of 53.27 ± 13.54 years. Of the 304 patients, 181 were symptomatic PHPT patients and 123 were asymptomatic PHPT patients. We analyzed the laboratory results, postoperative pathology, and the TNM stage of PTC between asymptomatic and symptomatic PHPT patients.

RESULTS

Concurrent thyroid nodules were found in 61.51% of PHPT patients, and the prevalence of PTC in thyroidectomized PHPT patients was 29.89% in our cohort. Lower serum parathyroid hormone (PTH) (p < 0.05) and calcium (p < 0.05) were found in PHPT patients with PTC compared to patients with benign thyroid lesion. Compared with the symptomatic PHPT patients, the asymptomatic PHPT patients showed lower serum calcium (p < 0.05), serum chlorine (p < 0.05), alkaline phosphatase (p < 0.05), PTH (p < 0.05), and bone turnover markers (p < 0.05) but higher prevalence of thyroid nodules (70.73% versus 55.24%, p < 0.05) and PTC (15.44% versus 3.87%, p < 0.05). All the PTC in symptomatic PHPT patients were papillary microcarcinoma limited to the thyroid, while 68.42% and 15.78% of the PTC in asymptomatic PHPT patients showed microscopic extrathyroidal extension and lymph node metastases, respectively. Moreover, 36.84% (7/19) of the PTC patients in asymptomatic group showed multifocality, which was much higher than 14.29% (1/7) in the symptomatic group; however, no statistical significance was found (p=0.24).

CONCLUSIONS

The concomitant PTC in asymptomatic PHPT patients showed a higher rate of microscopic extrathyroidal invasion when compared to symptomatic PHPT patients. So the FNA is essential to the asymptomatic PHPT patients with suspicious thyroid nodules and once the PTC is confirmed, concurrent parathyroidectomy should be performed with thyroidectomy in asymptomatic PHPT patients.

ARE THYROID NODULES AN OBSTACLE TO MINIMAL INVASIVE PARATHYROID SURGERY? A SINGLE-CENTER STUDY FROM AN ENDEMIC GOITER REGION

Context

Minimally invasive parathyroidectomy (MIP) procedure has become a widely accepted alternative to the standard four-gland exploration nowadays.

Objective

The aim of this study was to evaluate patients with primary hyperparathyroidism (PHPT), who had been treated with thyroidectomy and bilateral neck exploration (BNE), rather than MIP alone, due to coexisting thyroid nodules and to determine the benefits of simultaneous thyroidectomy and the possible negative outcomes of not performing this additional procedure.

Design

There were 185 patients who were operated for PHPT at our clinic from January 2014 to November 2016.

Subjects and Methods

50 patients meet inclusion criteria: have thyroidectomy at the same time of parathyroid surgery, have concordant findings of parathyroid adenoma localization at preoperative MIBI-SPECT and the cervical US and have not had malignancy on fine needle aspiration biopsy (FNAB).

Results

The mean age of the patients was 55.3±10.4, and female to male ratio was 7:1. All patients had parathyroidectomy with BNE and thyroidectomy: 11 (22%) patients had micropapillary thyroid cancer (mPTC), 2 (4%) had papillary thyroid cancer (PTC).

Conclusion

The results were inconclusive in clearly demonstrating which patients presenting with coexisted thyroid nodules should undergo thyroidectomy, rather than MIP, and which should be monitored for thyroid nodules after MIP. However, we consider that in cases who are not clearly indicated for thyroidectomy, MIP followed by monitoring of thyroid nodules can be the treatment approach.

Coexistent papillary thyroid carcinoma diagnosed in surgically treated patients for primary versus secondary hyperparathyroidism: same incidence, different characteristics

BACKGROUND

The coexistence of hyperparathyroidism and thyroid cancer presents important diagnostic and management challenges. With minimally invasive parathyroid surgery trending, preoperative thyroid imaging becomes more important as concomitant thyroid and parathyroid lesions are reported. The aim of the study was to evaluate the rate of thyroid cancer in patients operated for either primary (PHPT) or secondary hyperparathyroidism (SHPT).

METHODS

Our retrospective study included PHPT and SHPT patients submitted to parathyroidectomy and, when indicated, concomitant thyroid surgery between 2010 and 2017.

RESULTS

Parathyroidectomy was performed in 217 patients: 140 (64.5%) for PHPT and 77 (35.5%) for SHPT. Concomitant thyroid surgery was performed in 75 patients with PHPT (53.6%), and 19 papillary thyroid carcinomas (PTC) were found, accounting for 13.6% from all cases with PHPT and 25.3% from PHPT cases with concomitant thyroid surgery. Thirty-one of operated SHPT patients (40.3%) also underwent thyroid surgery and 9 PTC cases were diagnosed (11.7% of all SHPT patients and 29% of patients with concomitant thyroid surgery). We found differences between PHPT and SHPT patients (p < 0.001) with respect to age (54.6 ± 13y versus 48.8 ± 12y), female-to-male ratio (8:1 versus ~ 1:1), surgical technique (single gland parathyroidectomy in 82.8% PHPT cases; versus subtotal parathyroidectomy in 85.7% SHPT cases) and presurgical PTH (357.51 ± 38.11 pg/ml versus 1020 ± 161.38 pg/ml). Morphopathological particularities, TNM classification and multifocality incidence of PTC were similar in the two groups. All PTC from patients with SHPT were thyroid microcarcinomas (TMC, i.e. tumors with a diameter smaller than 1 cm), whereas seven out of the 19 cases with PTC and PHPT were larger than 1 cm.

CONCLUSIONS

PTC was frequently and similarly associated with both PHPT and SHPT irrespective of presurgical PTH levels. Thyroid tumors above 1 cm were found only in patients with PHPT. Investigators should focus also on associated thyroid nodular pathology in patients with PHPT.

Diagnostic accuracy of parathyroid hormone levels in washout samples of suspicious parathyroid adenomas: A single-centre retrospective cohort study

INTRODUCTION

Minimally invasive surgery is an alternative surgical approach for primary hyperparathyroidism with less surgical trauma and anaesthesia complications. When combined with intraoperative measurement of parathyroid hormone (PTH), cure rates are exceeding 97%. Preoperative intact PTH determination in washout samples is really very useful when parathyroid lesions cannot be easily distinguished from thyroid lesions or sometimes lymph nodes. Herein, we aimed to report our institutional experience about parathyroid fine-needle aspiration (FNA) method and suggest a cut-off ratio for this purpose.

METHODS

In our clinic, we performed ultrasonography (USG)-guided parathyroid FNA procedure for 131 patients diagnosed with primary hyperparathyroidism between January 2005 and January 2016. Both cytologic evaluation and intact PTH determination were performed in washout samples. Eighty-seven of the study group also had a parathyroid scintigraphy. Both demographic features and laboratory results were all recorded.

RESULTS

Median serum PTH level was 142 (113-197), while mean PTH washout level was 1824 (0-3953). When three of the localization techniques are compared with each other, FNA-PTH washout group had a better diagnostic accuracy (90.8%) when compared to cytology (7.92%) and MIBI (67.8%) groups. Both MIBI and FNA-PTH washout group had 100% positive predictive value (PPV) and 100% specificity. We found values greater than 436.5 pg/mL for FNA-PTH washout with a sensitivity of 90.3% and specificity of 88.9% (P < 0.01 and AUC 94.3 (87.8-100)) and a cut-off for FNA/serum PTH greater than 3.05 with a sensitivity of 91.2% and specificity of 89% (P = 0.02 and AUC 94.5 (88.8-100)) which implicate parathyroid lesions.

CONCLUSION

According to the literature, PTH determination in washout samples has a specificity of 75%-100% and sensitivity of 70%-100%. This approach has better results than both cytology and scintigraphy in case of concomitant multinodular thyroid disease in experienced hands. Although there is not a definite cut-off for PTH levels in washout samples, we agree with the need of ratios rather than cut-offs in this issue.

Can ARFI elastography be used to differentiate parathyroid from thyroid lesions?

OBJECTIVES

To assess if elasticity score (ES) and shear wave velocity (SWV) measurement obtained using ARFI elastography can differentiate between parathyroid lesions and thyroid nodules.

MATERIALS AND METHODS

ARFI elastography was performed on patients with primary hyperparathyroidism or solid thyroid nodules who were being considered for surgery using virtual touch quantification and virtual touch imaging (VTI) software. Only patients with surgical histopathology (47 parathyroid lesions, 38 benign thyroid nodules and 55 malignant thyroid nodules) were included for final analysis. SWV and ES of the parathyroid and thyroid nodules were compared and their ability to differentiate between parathyroid and thyroid was analyzed using receiver operating characteristic curve analysis.

RESULTS

There were 39 solitary adenomas, 2 double adenomas and 4 parathyroid hyperplasias with mean size of 19.6 ± 9.7 mm in 44 patients (21 male, 23 females) with primary hyperparathyroidism. The mean SWV of the parathyroid lesion (1.6 ± 0.78 m/s) was significantly different from benign (2.11 ± 0.8 m/s) and malignant (4.3 ± 2.71 m/s) thyroid nodules, p < 0.05; so was the ES, Chi square = 51.6, p < 0.001. The majority of parathyroid lesions (n = 37, 78.7%) had ES of 2 with speckled (n = 42, 89.3%) appearance, and none showed ES of 4. The diagnostic performance of speckled appearance on VTI, elasticity score and SWV measurements was 0.901, 0.724 and 0.797, respectively, to differentiate between parathyroid and thyroid lesions.

CONCLUSIONS

Parathyroid lesions are softer than thyroid nodules. A shear wave velocity of 1.72 m/s can differentiate between parathyroid lesions and thyroid nodules.

Concomitant thyroid disease and primary hyperparathyroidism in patients undergoing parathyroidectomy or thyroidectomy

BACKGROUND

Thyroid abnormalities have been found intraoperatively during parathyroidectomy and have resulted in concomitant thyroidectomy. The identification of concomitant disease is important prior to primary operation in order to minimize reoperations. This study investigates the incidence of concomitant primary hyperparathyroidism (PHPT) and thyroid nodular disease in patients undergoing thyroidectomy or parathyroidectomy.

METHODS

We performed a retrospective review of prospectively gathered data for 621 patients who underwent thyroidectomy, parathyroidectomy, or both at Tulane Medical Center. Information obtained included initial referral, initial thyroid stimulating hormone (TSH), initial parathyroid hormone (PTH), fine needle aspiration (FNA) results, ultrasound results, type of operation performed, final diagnosis, and final pathology.

RESULTS

Among the 400 patients referred primarily for thyroid disease, 13.50% underwent a thyroidectomy and parathyroidectomy (PTX) simultaneously and 10.75% received a final diagnosis of thyroid and concomitant parathyroid disease. Among the 103 patients referred primarily for parathyroid disease, 26.21% underwent a PTX and thyroidectomy and 24.27% received a final diagnosis of both thyroid and parathyroid disease. Patients referred primarily for parathyroid disease were more likely to receive a final diagnosis of both parathyroid and thyroid disease and were more likely to undergo a combined operation.

CONCLUSIONS

Concomitant thyroid and parathyroid disease occur and preoperative analysis is important to avoid increased complications from reoperations.

Management of concomitant hyperparathyroidism and thyroid diseases in the elderly patients: a retrospective cohort study

BACKGROUND

Thyroid disease and hyperparathyroidism are the most common endocrine disorders. The incidence of thyroid disease in patients with hyperparathyroidism ranges in the different series from 17 to 84%, and thyroid cancer occurs with an incidence ranging from 2 to 15%.

AIM

The aim of our study was to analyze the management of elderly patients with concomitant thyroid and parathyroid disease in order to define the best surgical therapeutic strategy and avoid reoperations associated with a higher risk of complications.

METHODS

All consecutive patients (64 patients, age range 60-75 years), undergoing surgery for hyperparathyroidism, from January 2011 to June 2014, were retrospectively evaluated. Enrolled patients were divided into two study groups of patients affected by hyperparathyroidism with or without a concomitant thyroid disease.

RESULTS

Out of 64 patients enrolled in our study (24 men, age range 60-75 years), affected by hyperparathyroidism, 34 had an associated thyroid disease and were treated with total thyroidectomy and parathyroidectomy. The group, who underwent parathyroidectomy associated with thyroidectomy, had no greater complications than the group receiving only parathyroidectomy.

CONCLUSIONS

Thyroid disease must be excluded in patients affected by hyperparathyroidism. It is difficult to determine whether hyperparathyroidism can be considered a risk factor for thyroid disease, but an accurate preoperative study is essential for a surgery able to treat both thyroid and parathyroid disease. In this way, we avoid the elderly patient, with associated morbidity and increased surgical risk, to undergo a reoperation for thyroid disease, burdened with major complications.

Surgical treatment of concomitant thyroid and parathyroid disorders: analysis of 4882 cases

The thyroid gland disease incidence in hyperparathyroidism (HPT) is higher than the incidence of thyroid disease in general population. Likewise, HPT is more frequent in patients primary admitted due to thyroid disease, than in general population. The aim of this study was to determine the incidence and clinical characteristics of concomitant HPT and thyroid disease, based on a single center experience. From 2009 to 2014, a total of 4882 patients underwent thyroidectomy and/or parathyroidectomy at the Center for Endocrine Surgery, Belgrade. We reviewed the database to find out indications for surgery, clinical characteristics, operative and histopathological findings. Out of 4033 patients, who underwent thyroidectomy, in 114 cases (2.8 %) parathyroidectomy was simultaneously performed. Out of these 114 patients, 42 patients (37 %) had normocalcemic HPT. Among 849 patients primary operated due to HPT, thyroid gland disease that required surgery was found in 224 (26.4 %). In patients primary seen for HPT, thyroid cancer was found in 22 (9.8 %), Hashimoto's thyroiditis in 41 (18.3 %) and micropapillary carcinoma in 36 cases (16.1 %). Due to residual or recidivant HPT, 16 patients (15 who primary underwent parathyroidectomy and 1 primary seen for thyroid disease) needed a reoperation. There are a considerable number of patients with concomitant thyroid and parathyroid disease; this justifies the routine analyses of calcemia and PTH level in patients preparing for thyroidectomy, and sets up the ground for the thyroid investigations in HPT.

Surgeon-driven thyroid interrogation of patients presenting with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (pHPT) is an increasingly prevalent disease affecting all age groups. The authors sought to determine the impact of a "thyroid interrogation" practice protocol on the surgical treatment of patients with the diagnosis of pHPT referred to a single surgeon.

STUDY DESIGN

We performed a retrospective review of prospectively gathered data on parathyroidectomy (PTX) patients undergoing both a prospective clinical thyroid evaluation and thyroid ultrasound between January 2008 and October 2012.

RESULTS

Only 5.6% of 468 PTX patients were referred to a single surgeon for both parathyroid and thyroid surgical evaluation; 31% of patients had known pre-existing thyroid disease (hypothyroidism most commonly), and 22% of patients had palpable thyroid abnormalities unrecognized in 67% of cases by the referring physician. Of the 468 patients, 2.6% had a history of classic head and neck radiation exposure, 2.6% a history of radio-iodine treatment, and 3% a family history of thyroid cancer. Thyroid abnormalities were found on ultrasound in 61% of patients, and 26% of patients underwent thyroid biopsies. Parathyroid and thyroid surgery was combined for 18.4% of patients; indications included obstructive symptoms (3.2%), hyperthyroidism (0.9%), intraoperative findings (5.1%), and concern for malignancy (9.2%). Malignancy was diagnosed in 23 patients (4.9%), only 8 of whom had been referred for thyroid evaluation.

CONCLUSIONS

The majority of patients referred for PTX had evidence of thyroid pathology. For an important minority of these patients, benign and malignant disease was identified that merited surgical treatment at the time of PTX. We recommend comprehensive thyroid evaluation of patients referred for PTX.

Parathyroid incidentalomas detected during thyroid ultrasonography and effect of chronic thyroiditis on false positive parathyroid lesions

We aimed to determine the prevalence of parathyroid incidentalomas in patients referred for thyroid ultrasonography (US) and investigate the role of chronic thyroiditis on false positive lesions. Patients suspected to have parathyroid lesions during thyroid US were recorded prospectively between August 2009 and January 2010. Patients referred for parathyroid US and patients with known high serum calcium or parathyroid hormone (PTH) levels were excluded. Suspected parathyroid lesions were defined as hypoechoic, homogeneous, solid lesions with regular margins located outside the thyroid lobe, most commonly inferior to the thyroid gland. Thyroid US was performed in 6,528 patients. There were 78 patients (1.19 %) (73 female and 5 male) with suspected parathyroid lesion. The diagnosis of a true parathyroid adenoma was confirmed in 6 (7.69 %) patients. In patients with true adenoma, mean serum calcium, phosphorus, and PTH levels were 10.57 ± 0.48 mg/dl, 3.03 ± 0.52 mg/dl, and 182.91 ± 46.62 pg/ml, respectively. Among 72 patients with false positive parathyroid lesion, antithyroid peroxidase antibody was positive in 50 (69.4 %), antithyroglobulin antibody was positive in 46 (63.9 %), and one of these antibodies were positive in 59 (81.9 %) patients. Also, 46 (63.9 %) of these patients had thyroid dysfunctions (43 hypothyroidism and 3 hyperthyroidism) and 59 (81.9 %) had chronic thyroiditis ultrasonographically. Parathyroid incidentaloma was detected in 0.09 % of patients referred for thyroid US. The presence of clinically or ultrasonographically chronic thyroiditis might cause inadvertent interpretation of a hypoechoic lesion as a parathyroid pathology during thyroid US.

Incidence of concomitant hyperparathyroidism in patients with thyroid disease requiring surgery

BACKGROUND

Thyroid disease and hyperparathyroidism (HPT) are among the most common endocrine disorders, however, their association has not been well established. The aim of the present study was to determine the incidence of concomitant HPT in patients with thyroid disease requiring surgery, because a single definitive surgery should ideally be performed.

METHODS

We retrospectively reviewed a prospectively maintained database of patients who underwent thyroidectomy at a single institution. Data collected included the patients' initial indication for surgery, preoperative workup, and operative findings.

RESULTS

Of the 1,049 patients who underwent thyroidectomy, 56 (5%) had concomitant HPT and underwent simultaneous parathyroidectomy. Of these 56 patients, 36 initially presented with thyroid disease and 20 with HPT. The mean age was 59 ± 2 years, and 79% were women. The mean preoperative calcium and parathyroid hormone levels were elevated at 10.4 ± 0.1 mg/dL and 87 ± 7 pg/mL, respectively. Most of these patients had primary HPT (n = 54, 96%). Of the 36 patients presenting initially with thyroid disease, 26 had an elevated calcium or parathyroid hormone value and were preoperatively diagnosed with HPT. The remaining 10 patients had normal laboratory findings; however, a pathologically enlarged parathyroid gland was found at thyroidectomy. The overall cure rate for HPT within our series was 96%.

CONCLUSION

The incidence of concomitant HPT in patients with thyroid disease requiring surgery is significant at 5%. Recognition of concurrent disease is important, because it allows for a single definitive surgery to treat both pathologies.

Minimally invasive parathyroidectomy: benefits and requirements of localization, diagnosis, and intraoperative PTH monitoring. long-term results

BACKGROUND

Surgery is the only curative treatment for primary hyperparathyroidism. Initial parathyroidectomy procedures fail due to ectopic gland location and unappreciated multigland disease.

METHODS

An evidence-based literature review was performed,which surveyed all human studies in PubMed, searching for parathyroidectomy in humans between 1990 and 2009. Between 10 and 30% of patients have multigland disease caused by double adenomas or hyperplasia. Use of preoperative imaging studies and intraoperative PTH monitoring helps parathyroid surgeons overcome these obstacles.

RESULTS

Sestamibi nuclear scan and neck ultrasound identify 70-80% of abnormal glands in patients with single adenomas. The sensitivity of ultrasound or sestamibi to identify all abnormal glands in patients with multigland disease is extremely low. Intraoperative PTH monitoring should be utilized in all patients who undergo neck exploration for primary hyperparathyroidism to reduce failures due to multigland disease. Blood samples should be drawn from peripheral veins only and a postresection level 10-15 min after gland removal should have a >50%decrease from baseline preoperative levels, and also must go to the normal range for the PTH assay being used.

CONCLUSIONS

Contemporary prospective studies (level of evidence III/IV) show that by combining preoperative imaging and IOPTH it is possible to maximize performance of successful outpatient minimally invasive parathyroidectomy.

[High retention of (99m)Tc-MIBI in delayed phase as a pitfall in the combined parathyroid-thyroid scintigraphy]

Dual phase parathyroid scintigraphy with (⁹⁹m)Tc-sestaMIBI is a very sensitive technique in the preoperative localization and diagnosis of parathyroid adenoma. However, pitfalls have been reported in patients with thyroid nodules with MIBI uptake or with previous thyroid surgery. To solve this problem, a thyroid scintigraphy with (⁹⁹m)Tc-pertechnetate is usually performed following the parathyroid study. Occasionally, as in our patient the parathyroid lesion may show high MIBI uptake and delayed washout that interfere with the subsequent thyroid scintigraphy giving the false appearance of a pertechnetate avid lesion. This has been called the «shine through» effect. To avoid it, the parathyroid and thyroid scintigraphies can be performed on separate days. We have also found it useful to compare our results with that of ultrasound and fine needle aspiration puncture with measurement of the parathyroid hormone (PTH) and thyroglobulin in the aspirated material.

Institutional experience of PTH evaluation on fine-needle washing after aspiration biopsy to locate hyperfunctioning parathyroid tissue

Assaying parathyroid hormone (PTH) in the washing liquid after fine-needle aspiration biopsy (FNAB) seems to be a valid approach to locate parathyroid tissue. PTH-FNAB was evaluated in 47 patients with a clinical picture of primary hyperparathyroidism (PHP) and ultrasonography (US) suggestive of parathyroid lesion. The patients were subdivided into two groups on the basis of the absence or presence of US thyroid alterations. The result of PTH-FNAB was compared with those of cytology, scintigraphy and, in 24 patients, surgical outcome. PTH-FNAB samples with a value higher than that recorded in the serum and higher than our institutional cut-off were deemed to be probable samples of parathyroid tissue. Cytology proved diagnostic for benign thyroid lesions, non-diagnostic for thyroid lesions, hyperplastic parathyroid tissue, undetermined or malignant thyroid lesions and other lesions in 45%, 30%, 17%, 4%, and 4% of cases, respectively. In 47% of cases, PTH-FNAB indicated that the sample had been taken in parathyroid tissue. In patients without US alterations, the diagnostic accuracy of PTH-FNAB was greater than that of scintigraphy. After surgery, comparison between the results of PTH-FNAB and scintigraphy, in terms of positive predictive value (PPV), revealed the superiority of PTH-FNAB; PPV was 94% for FNAB and 71% for scintigraphy, while sensitivity was 83% and 69%, respectively. PTH-FNAB evaluation after FNAB appears to be more diagnostic than cytology and scintigraphy. Of all the procedures used, PTH-FNAB appears to be the method of choice when the target is US suggestive and reachable. PTH-FNAB appears to be a useful method of guiding surgical intervention.