Preoperative localization of suspicious parathyroid adenomas by assay of parathyroid hormone in needle aspirates

Diagnosis of parathyroid incidentaloma detected on thyroid ultrasonography: the role of fine-needle aspiration cytology and washout parathyroid hormone measurements

PURPOSE

The aim of this study was to assess the diagnostic role of fine-needle aspiration cytology (FNAC) and analyze factors associated with false-negative FNAC results in patients with parathyroid incidentaloma who were referred for ultrasonography (US)-guided fine-needle aspiration (FNA) of thyroid nodules.

METHODS

In this study, 121 patients with suspected parathyroid lesions were enrolled. The patients underwent US-guided FNAC with measurements of washout parathyroid hormone (PTH) between January 2015 and May 2020. The diagnostic performance of FNAC for the diagnosis of parathyroid lesions was assessed using surgical results and elevated washout PTH as a reference standard. The clinical and radiologic features associated with false-negative results on FNAC for the diagnosis of parathyroid lesions were evaluated.

RESULTS

Among the 121 nodules assessed, 38 were parathyroid lesions (31.4%), and 83 were non-parathyroid lesions (68.6%). The diagnostic performance of FNAC for parathyroid incidentaloma showed a sensitivity of 31.6% (12/38), specificity of 100% (83/83), positive predictive values of 100% (12/12), negative predictive values of 76.1% (83/109), and accuracy of 78.5% (95/121). The FNAC results of non-parathyroid lesions included thyroid nodules, lymph nodes, neurogenic tumors, and fat tissue. True-positive results on FNAC were significantly associated with performing FNA twice (58.3% vs. 23.1%, P=0.043).

CONCLUSION

Considering the low sensitivity of FNAC, measuring washout PTH in addition to FNAC may help accurately diagnose parathyroid incidentaloma on thyroid US. Further, the falsenegative rate for FNAC can be reduced by obtaining two or more FNA samples.

Positive predictive values of ultrasound-guided fine-needle aspiration with parathyroid hormone assay and Tc-99m sestamibi scintigraphy in sporadic primary hyperparathyroidism

OBJECTIVES

Ultrasonography (US) and Tc-99m sestamibi scintigraphy (SS) are usually performed as preoperative imaging modalities for patients with sporadic primary hyperparathyroidism (SPHP). Fine-needle aspiration (FNA) under US guidance for parathyroid hormone (PH) assay can enhance the diagnostic accuracy of US. The main aim of the present study was to compare positive predictive values between US-FNA and SS. The secondary aim was to draw up a decision-tree for FNA and SS.

METHODS

The single-center retrospective study included patients with previously non-operated SPHP. They underwent US-guided FNA, PET-CT SS, and 18 F-choline scintigraphy if the first two methods were inconclusive. PH washout level was considered pathological when greater than the serum PH level. Postoperative histology data were correlated to imaging data.

RESULTS

In total, 117 patients were included, with a mean age of 64 years (range, 26-89 years). A single adenoma was identified on pathology in 101 patients (89%). FNA findings were pathologic for 64 patients (55%), with a mean PH level of 2,604ng/L [range, 585-9,074ng/L], higher than the serum level of 179ng/L [range, 60-1,000ng/L]. US-guided FNA showed sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of respectively 72%, 92%, 99% and 28%, compared to 89%, 42%, 93% and 32% for SS. The rate of error in locating the parathyroid gland was 8% for US-guided FNA versus 12% for SS. Comparison of the two methods showed better sensitivity for SS (P=0.0052) and better specificity for FNA (P=0.0143), with no significant difference in PPV or NPV. 18 F-choline scintigraphy detected the hyperfunctioning parathyroid in 11 out of the 15 patients.

CONCLUSION

PPV did not significantly differ between FNA and SS. US-guided FNA performed by an experienced operator could be a simple first-line method for more than 50% of patients with non-operated SPHP, with 99% PPV. In case of negative or doubtful FNA findings, SS can be performed in second line.

The Current Role of Parathyroid Fine-Needle Biopsy (P-FNAB) with iPTH-Washout Concentration (iPTH-WC) in Primary Hyperparathyroidism: A Single Center Experience and Literature Review

Introduction. Primary hyperparathyroidism (PHPT) is a condition characterized by disorders of calcium–phosphate metabolism and bone metabolism caused by pathological overproduction of parathyroid hormone (PTH). The diagnosis of overt PHPT is based on the presence of clinical symptoms and laboratory abnormalities typical of this condition: hypercalcemia, hypercalciuria and elevated iPTH levels. Imaging studies are not used for diagnostic purposes; they are performed to localize the parathyroid glands prior to potential surgical treatment. Technetium 99 m sestamibi scintigraphy (Tc99 m-MIBI) is the gold standard in the assessment of pathologically altered parathyroid glands. Other diagnostic options include cervical ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). Parathyroid biopsy (P-FNAB) with iPTH washout concentration (iPTH-WC) assessment is still an underestimated method of preoperative parathyroid gland localization. Few studies have reported the utility of US-guided P-FNAB in preoperative assessment of parathyroid lesions. The aim of the study was to present our experience with 143 P-FNAB with iPTH-WC assessment. Material and methods. Laboratory results, US findings, P-FNAB complications and comparison with other imaging techniques were described and analyzed. Results. In 133 (93.0) patients, iPTH washout-to-serum ratio exceeded threshold level 0.5 and were classified as positive results. Median iPTH-WC in this group was 16,856 pg/mL, and the iPTH-WC to serum iPTH ratio was 158. There was no correlation between iPTH-WC and serum PTH, serum calcium, parathyroid gland volume and shape index. In the group of 46 operated patients, 44 demonstrated positive iPTH-WC results, which corresponds to a sensitivity of 95.6%. In Tc99-MIBI, radiotracer retention was found in 17 cases (in 24 MIBI performed), which corresponds to a sensitivity of 52.2%. P-FNAB did not cause any major side effects −92.5% of all patients had no or mild adverse events after this procedure. Conclusions. P-FNAB with iPTH-WC is a reliable method in parathyroid adenoma localization during PHPT. Its sensitivity for diagnosis of PHPT is much higher than that of Tc99-MIBI, and in some situations, P-FNAB with iPTH-WC may even replace that method. Furthermore, cost-effectiveness of iPTH-WC is at least similar to that of Tc99-MIBI. Complications of P-FNAB are mild and we can describe this method as a safe procedure.

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.

Complementary role of parathormone washout test to 99mTc-MIBI parathyroid scintigraphy and histopathologic analysis of cell types in parathyroid adenomas

OBJECTIVE

Parathyroid scintigraphy (PS) can be negative or equivocal (N/E) in a considerable number of cases with highly suspicious clinical findings and biochemical results for parathyroid adenoma (PA). The aims of this study were to investigate the complementary role of parathormone washout test (PWT) to PS in patients with primary hyperparathyroidism (PHPT) and evaluate histopathologic aspects of PAs in comparison with PS results.

MATERIAL AND METHODS

Thirty-eight patients with PHPT referred for PS were included in the study. Seventeen patients had both scintigraphic and ultrasonographic findings concordant with PA (Group A). Twenty-one patients having N/E PS, but suspected lesions for PA on ultrasonography (US) formed Group B. PWT was performed for all patients and they underwent the surgical intervention. An adenoma was removed in all patients and the histopathologic cell characteristics were established.

RESULTS

The tumor size on US was larger in those patients whose adenomas were seen on the PS (P<.001). The percentages of chief (or principal), oxyphilic and clear cells in PAs were not statistically different between the groups. Serum parathormone level and PWT were not statistically significant between Group A and Group B (P=.095 and P=.04, respectively).

CONCLUSION

Although there is not a definitive threshold value, the sensitivity of PS increases with lesion size. While chief cell and oxyphilic cell content of PAs tend to deplete in N/E PS, clear cell rate increases substantially. Combining PS with both US and PWT increases the sensitivity of detection and localization of PAs.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, AMERICAN COLLEGE OF ENDOCRINOLOGY, AND ASSOCIAZIONE MEDICI ENDOCRINOLOGI MEDICAL GUIDELINES FOR CLINICAL PRACTICE FOR THE DIAGNOSIS AND MANAGEMENT OF THYROID NODULES--2016 UPDATE

Thyroid nodules are detected in up to 50 to 60% of healthy subjects. Most nodules do not cause clinically significant symptoms, and as a result, the main challenge in their management is to rule out malignancy, with ultrasonography (US) and fine-needle aspiration (FNA) biopsy serving as diagnostic cornerstones. The key issues discussed in these guidelines are as follows: (1) US-based categorization of the malignancy risk and indications for US-guided FNA (henceforth, FNA), (2) cytologic classification of FNA samples, (3) the roles of immunocytochemistry and molecular testing applied to thyroid FNA, (4) therapeutic options, and (5) follow-up strategy. Thyroid nodule management during pregnancy and in children are also addressed. On the basis of US features, thyroid nodules may be categorized into 3 groups: low-, intermediate-and high-malignancy risk. FNA should be considered for nodules ≤10 mm diameter only when suspicious US signs are present, while nodules ≤5 mm should be monitored rather than biopsied. A classification scheme of 5 categories (nondiagnostic, benign, indeterminate, suspicious for malignancy, or malignant) is recommended for the cytologic report. Indeterminate lesions are further subdivided into 2 subclasses to more accurately stratify the risk of malignancy. At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data, US signs, elastographic pattern, or results of other imaging techniques to improve the management of these lesions. Most thyroid nodules do not require any treatment, and levothyroxine (LT4) suppressive therapy is not recommended. Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while US-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules. Surgery remains the treatment of choice for malignant or suspicious nodules. The present document updates previous guidelines released in 2006 and 2010 by the American Association of Clinical Endocrinologists (AACE), American College of Endocrinology (ACE) and Associazione Medici Endocrinologi (AME).

Focused parathyroidectomy without intra-operative parathormone monitoring: The value of PTH assay in preoperative ultrasound guided fine needle aspiration washout

Background

The accurate identification of hyperfunctioning parathyroid (HP) gland is the only issue for definitive surgical treatment in primary hyperparathyroidism (pHPT). Various imaging and operative techniques have been proposed to confirm the localization of the diseased gland. Nevertheless, none of these methods proved to be the gold standard. The presented study aimed to assess the value of parathyroid hormone assay in preoperative ultrasound guided fine needle aspiration (FNA)-PTH washout fluid to verify the correct localisation for focused parathyroidectomy without intra-operative PTH monitoring.

Material and Methods

The retrospective analysis of 57 patients with pHPT who underwent FNA-PTH was conducted from a prospective database. Biochemical assessment together with radiological (ultrasonography) and nuclear (MIBI scan) imaging was reviewed. Associations between FNA-PTH washout values and localization technics were evaluated and compared in terms of operative findings.

Results

Focused parathyroidectomy without intraoperative PTH monitoring was performed to 45 patients with high FNA-PTH values. The median largest diameter of the target parathyroid lesion identified by ultrasonography was 13 mm (range, 6 to 36). The median serum PTH level was 190 pg/mL (range, 78 to 1709; reference range, 15 to 65) whereas the median washout PTH was 2500 pg/mL (range, 480 to 3389). According to operative findings high FNA-PTH levels correctly identified parathyroid adenoma in 40 cases (89% of sensitivity and 100% of specificity and positive predictive value) whereas MIBI scan localized the lesion in 36 of these cases (80% of sensitivity).

Conclusions

The higher level of PTH in preoperative ultrasound guided FNA washout is a considerable data to predict the correct localization of HP, particularly in circumstances of greater values than the serum PTH level. However, although its specificity is high, in cases of coexisting nodular thyroid disease, associated additional HP might be missed at focused parathyroidectomy without PTH monitoring, leading to recurrent disease.

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Preoperative FNA-PTH washout and intraoperative US together give accurate information about localization of parathyroid adenomas.

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In this circumstances, focused parathyroidectomy without intraoperative PTH monitoring might be feasible and successful.

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Nevertheless, misdiagnosis due to concomitant nodular thyroid disease is a fact that always merit consideration.

Analytical and clinical validation of parathyroid hormone (PTH) measurement in fine-needle aspiration biopsy (FNAB) washings

BACKGROUND

Parathyroid hormone (PTH) quantitation in fine needle aspirate biopsy (FNAB) saline washings complements current modalities for parathyroid tissue localization.

OBJECTIVES

To establish the performance characteristics of the Roche Elecsys intact PTH immunoassay in FNAB needle washings and its diagnostic performance for the identification of parathyroid tissue.

DESIGN AND METHODS

Accuracy, precision, reportable range, and analytical specificity and sensitivity for the intact PTH immunoassay in FNAB needle washings were established. For clinical validation, 93 specimens from 79 patients were evaluated. Diagnostic cut-offs were established via receiver operator characteristic (ROC) curve analysis. Performance of PTH in FNAB needle washings was compared to cytology.

RESULTS

Measurement of the PTH in FNAB needle washings demonstrated a matrix interference that was overcome by supplementation of the samples with a protein based matrix prior to analysis. ROC area under the curve (AUC) was 0.96 for PTH in FNAB needle washings. A PTH concentration ≥100pg/mL showed 100% specificity and 82% sensitivity for identifying parathyroid tissue. On histology-confirmed parathyroid specimens, 21/38 (55%) were correctly identified by cytology; whereas 31/38 (82%) were identified by PTH.

CONCLUSIONS

Measurement of PTH in FNAB washings complements cytology for identification of parathyroid tissue. Analytical validation to exclude interference in the PTH immunoassay and proper localization of the parathyroid tissue by ultrasound is necessary to ensure the robustness of the method.

Parathyroid incidentaloma

Incidentalomas are lesions which are asymptomatic and detected incidently during imaging or surgery. Parathyroid incidentalomas are a rare entity. Enlargement of gland without hyperfunction may be an early stage of disease. Symptomatology is usually non-specific or related to renal and skeletal system. Total serum calcium estimation may be used as a screening modality. Sestamibi scan is a more accurate imaging technique than USG. FNAB - PTH measurement is the most reliable minimally invasive nonsurgical test for parathyroid tissue verification. Incidently discovered enlarged parathyroid gland may be removed to avoid a re-do surgery.

Risks and benefits of parathyroid fine-needle aspiration with parathyroid hormone washout

OBJECTIVE

To describe the experience with parathyroid fine-needle aspiration (FNA) and parathyroid hormone (PTH) washout at Mayo Clinic Rochester, Rochester, Minnesota.

METHODS

We retrospectively reviewed all parathyroid FNA procedures performed at Mayo Clinic Rochester between January 2000 and December 2007. Clinical, biochemical, and imaging information, parathyroid FNA procedure, and cytology, surgical, and pathology reports were reviewed, and descriptive statistics, sensitivity, specificity, and positive predictive values are presented.

RESULTS

During the study period, 75 parathyroid FNAs were performed on 74 patients. Cytology results were available for 74 of 75 procedures, with only 31% interpreted as parathyroid cells. PTH washout was performed in 67 patients (91%). Parathyroid FNA with PTH washout had a sensitivity of 84%, specificity of 100%, positive predictive value of 100%, and accuracy of 84%. At the time of surgical treatment, 2 patients were noted to have an inflammatory response from the parathyroid FNA biopsy, 1 had a parathyroid abscess, and 2 had a hematoma. In 3 of these 5 patients, the necessary conversion of a minimally invasive surgical procedure to the standard surgical approach prolonged the surgical time.

CONCLUSION

Parathyroid FNA with PTH washout had a superior performance in comparison with parathyroid scanning or ultrasonography alone. The main limitations of parathyroid FNA with PTH washout are (1) the need for initial identification of a potential parathyroid adenoma by ultrasonography and (2) the number of false-negative results. Parathyroid FNA resulted in complications affecting the surgical procedure in 3 patients.

Thyroid diseases cause mismatch between MIBI scan and neck ultrasound in the diagnosis of hyperfunctioning parathyroids: usefulness of FNA-PTH assay

DESIGN

To evaluate the efficacy of the main tools in the diagnostic localization of hyperfunctioning parathyroids (HP) in primary hyperparathyroidism (pHPT) with concomitant thyroid diseases.

METHODS

Forty-three patients with pHPT associated with nodular goiter (NG, n=32) and/or autoimmune thyroid diseases (AITDs, n=11) for a total of 63 neck lesions were considered. Sixteen patients displaying HP (16 lesions), unequivocally localized by sestaMIBI scintigraphy (MIBI) and neck ultrasound (US) (group I), were compared with 27 patients (47 neck lesions) displaying equivocal parathyroid localization (group II). In all cases, neck US, MIBI scan, cytology, and parathyroid hormone assay in fine-needle aspiration washout fluid (FNA-PTH) were performed. All patients finally underwent surgery.

RESULTS

According to histological examination, high FNA-PTH values (>103 pg/ml) correctly identified all HP in both groups of patients (100% of sensitivity and specificity). Both MIBI and US correctly identified all HP only in group I patients; in contrast, four patterns of mismatch between these techniques were observed in group II patients, leading to low diagnostic performances of neck US (71.4% sensitivity and 78.9% specificity) and of MIBI scan (35.7% sensitivity and 42.1% specificity). The latter was due to both false-negative (mainly in AITD) and false-positive (mainly in NG) scan images.

CONCLUSIONS

Coexistent thyroid diseases are responsible for mismatch between MIBI and US images resulting in equivocal HP localization. In these cases, FNA-PTH resulted in the most accurate tool to identify HP. However, although safe, it should be advised only to patients with uncertain HP localization.

Fine-needle aspiration for proteomic study of tumour tissues

Fine-needle aspiration (FNA) is a technique largely applied in the diagnosis of tumours. FNA is a safe diagnostic procedure that is widely employed in the examination of masses at relatively low cost and minimal risk to the patient. In this review, we report on the state-of-the-art and the potential role of FNA to search for protein biomarkers by the proteomic approach.

Intraoperative determination of PTH concentrations in fine needle tissue aspirates to identify parathyroid tissue during parathyroidectomy

BACKGROUND

Exact tissue identification during parathyroidectomy is essential to successfully cure hyperparathyroidism. PTH level determination from tissue aspirates has been advocated as a "biochemical frozen section" for parathyroid tissue identification. We investigated the sensitivity and specificity of this method in a large cohort of consecutive patients who underwent parathyroidectomy in a tertiary referral center.

METHODS

PTH levels of 359 tissue aspirates were measured intraoperatively in 223 consecutive patients from March 2006 to December 2008. Suspected parathyroid and control tissues were aspirated with a standardized technique immediately after their excision. Samples were processed for quick-PTH assay with peripheral blood samples before and after excision. PTH levels from tissue aspirates were correlated with pathological diagnosis. The Mann-Whitney test was used to determine statistical significance (P < 0.05).

RESULTS

A total of 255 parathyroid (196 adenoma, 30 hyperplasia, 4 carcinoma, 25 normal parathyroid) and 104 nonparathyroid tissue (88 thyroid, 16 lymph node, thymus, or fat) aspirates were compared. A highly significant difference was found between PTH levels of parathyroid (8,120 +/- 2,711 pg/ml; interquartile range (IQR): 4,949-9,075) and nonparathyroid (0.8 +/- 9.29 pg/ml; IQR: 0.4-1.4) tissue aspirates (P < 0.005). This test is 100% sensitive and 100% specific to identify parathyroid tissue for values >84 pg/ml. Furthermore, PTH levels of pathological parathyroid aspirates (8,169 +/- 2,597; IQR: 5,634-9,109) were higher than that of normal parathyroid aspirates (4,130 +/- 2,952; IQR: 2,569-8,284; P = 0.0011).

CONCLUSIONS

PTH level determination from tissue aspirates is a highly reliable, quick, and simple method to differentiate parathyroid and nonparathyroid tissues during parathyroidectomy. This method can obviate frozen sections in patients undergoing surgery for hyperparathyroidism.

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.

Surgeon-performed ultrasound in patients referred for thyroid disease improves patient care by minimizing performance of unnecessary procedures and optimizing surgical treatment

BACKGROUND

Ultrasonography has become an indispensable tool in the evaluation of thyroid nodular disease, and most patients will have had a thyroid ultrasound prior to initial surgical evaluation. This study examines the added benefit of office-based, surgeon-performed ultrasonography in patients referred for thyroid disease.

METHODS

All patients referred to a single endocrine surgeon for evaluation of thyroid disease over a 2-year period were reviewed. Outside ultrasonographic findings were compared to the surgeon-performed ultrasound that was used to formulate treatment decisions.

RESULTS

Of 286 consecutive patients referred for surgical evaluation of thyroid disease, 261 had an outside ultrasound available for comparison. There were 239 women and 47 men. Mean age was 54.7 +/- 16.6. In 46 patients (17.6%), differences between the two ultrasounds were significant enough to alter treatment plans. For 18 patients no distinct nodule was identified and biopsy was avoided. Nine of these patients had ultrasound characteristics of Hashimoto's disease. In five patients the nodule was significantly smaller than reported and biopsy was not warranted. Twelve patients had nonpalpable, enlarged lymph nodes not previously identified; these were biopsied. Three were positive for metastatic thyroid cancer, which prompted the addition of neck dissection to the operative procedure. In 8 of 132 patients undergoing thyroidectomy, the surgical procedure was significantly altered by the ultrasound findings.

CONCLUSIONS

This study demonstrates a clear advantage for patients who undergo a surgeon-performed ultrasound. For many, unnecessary procedures were prevented. For others, substantial modifications to the extent of surgery were made when new ultrasonographic findings were identified during the preoperative investigation.

Endoscopic ultrasound-guided fine-needle aspiration with aspirate assay to diagnose suspected mediastinal parathyroid adenomas

OBJECTIVE

To describe our experience with mediastinal parathyroid adenomas diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and measurement of parathyroid hormone.

METHODS

We describe the clinical and pathologic findings and diagnostic techniques used in 2 study patients.

RESULTS

Patient 1 was a 54-year-old man with persistently elevated serum calcium and parathyroid hormone concentrations despite removal of a right inferior parathyroid adenoma. An echoendoscope was used to identify the lesion and to perform FNA. The parathyroid hormone concentration measured in the aspirated material was 1800 pg/mL. Pathologic examination of the resected specimen revealed a 29.7-g parathyroid adenoma. Patient 2 was an 86-year-old woman with recurrent hyperparathyroidism. A linear array echoendoscope was used to perform FNA of the lesion in her mediastinum. The parathyroid hormone concentration measured in the aspirated specimen was 6905 pg/mL.

CONCLUSIONS

Preoperative localization of recurrent or persistent hyperparathyroidism is often difficult. EUS-FNA allows evaluation of masses, such as those found in the mediastinum, that are poorly evaluated by other imaging modalities. This technique may be a useful adjunct in diagnosing mediastinal parathyroid adenomas.

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.

Diagnostic aspiration of parathyroid adenomas causes severe fibrosis complicating surgery and final histologic diagnosis

OBJECTIVE

To determine whether fine-needle aspiration (FNA) of parathyroid adenomas may cause a severe fibrotic reaction of the gland and surrounding structures, making surgery more difficult and histology more confusing.

DESIGN

A study was conducted over a 33-month period to compare the operative findings of 30 patients who underwent FNA of a parathyroid adenoma to those of 3000 patients who had not had their parathyroid tumor aspirated. Each patient's normal parathyroid glands also served as internal controls. All aspirations were performed by referring physicians under direct ultrasound guidance within 3 months of surgery, and all adenomas were located in routine positions. Patients who had previous thyroid or parathyroid surgery were not included. Patients with secondary or tertiary hyperparathyroidism were not included.

MAIN OUTCOME

The control group (non-FNA) showed a fibrotic reaction in 127 (4.3%) tumors appreciated by the surgeon and recognized on histology. In contrast, tumors undergoing FNA had a dense and often severely fibrotic reaction seen at surgery in 19 of 30 (63%) (p < 0.0001) and on histology in 23 of 30 (77%) (p < 0.0001). The fibrotic reaction appeared to mimic malignancy on histology and increased in occurrence with increased numbers of aspiration passes and larger needle bore (p < 0.05). No normal glands (n > 7500) or hyperplastic glands (n = 488) demonstrated fibrosis in any patient. Tumors that were aspirated required an eightfold increase in time to remove (p < 0.005) and more than doubled the total operative time (p < 0.05).

CONCLUSIONS

FNA of parathyroid adenomas can cause a severe fibrotic process that typically involves adjacent tissues. This reaction dramatically increases the difficulty of surgical resection, often requiring microdissection techniques to preserve nerves and assure complete removal. The fibrosis can cause confusing histology mimicking malignancy. FNA of parathyroid adenomas should be avoided unless absolutely necessary.

Multidetector CT in diagnostic work-up of patients with primary hyperparathyroidism

PURPOSE

This study was performed to evaluate the accuracy of multidetector computed tomography (MDCT) in detecting parathyroid lesions in patients with primary hyperparathyroidism.

MATERIALS AND METHODS

We included 60 patients with primary hyperparathyroidism. Preoperative first-line examinations revealed negative and doubtful ultrasound (US) findings in 34 and 26 cases, respectively, and negative, doubtful and positive scintigraphic findings in 19, 20 and 21 cases, respectively. CT findings were compared with the surgical results.

RESULTS

CT examination was positive in 35 cases, negative in 15 cases and doubtful in ten cases. Forty out of 60 patients underwent surgery, and 39 lesions (37 adenomas, two primary hyperplasias) were identified. Surgery was negative in two cases. In eight cases, lesions had ectopic location. Surgery confirmed the CT findings in 23 positive cases. In 8/10 doubtful cases, surgery confirmed the location of the lesion in five cases, identified the ectopic location of lesions in two cases, and was negative in one case. In 9/15 cases with negative CT findings, surgery identified the lesion in eight cases. Sensitivity, specificity and diagnostic accuracy values were 78%, 25% and 73%, respectively.

CONCLUSIONS

MDCT is an accurate second-line diagnostic technique in the detection of parathyroid lesions, allowing exploration of the entire cervical and mediastinal regions.

Parathyroid sonography: imaging and intervention

This article reviews the role of high-resolution sonography as an imaging modality for the diagnosis and treatment of patients with parathyroid disease. Included is a discussion of sonographic anatomy and technique, disease processes of the parathyroid glands and their sonographic appearances, preoperative imaging, and the use of sonography as a guide for diagnostic and therapeutic intervention in parathyroid disease.

Worrisome histologic alterations following fine-needle aspiration of the parathyroid

Fine-needle aspiration (FNA) is a procedure that is increasingly being performed. Artefacts occurring after FNA are reported to complicate the histological analysis of the tissue, mainly in the thyroid; WHAFFT (worrisome histologic alterations following FNA of thyroid) is well documented in the literature. The case of a male patient with hypercalcaemia who was subsequently found to have a nodule in the thyroid gland is reported here. He underwent FNA, followed by a total thyroidectomy and parathyroidectomy. The abnormality in the parathyroid gland showed worrisome histological changes that were suspicious of a malignant lesion, resembling the changes seen in the thyroid gland after FNA. Parathyroid cells were identified by a review of the previous FNA. The concept of WHAFFT, which can mimic the features of malignancy in the parathyroid gland, is therefore introduced.

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.

Use of surgeon-performed office ultrasound and parathyroid fine needle aspiration for complex parathyroid localization

BACKGROUND

This study investigates the utility of ultrasound guided parathyroid fine needle aspiration (FNA) as a localizing technique in patients with hyperparathyroidism (HPT) undergoing re-operative neck surgery or with unusually appearing or ectopically located glands.

METHODS

Selected patients with HPT underwent surgeon-performed FNA with ultrasound guidance. Aspirate contents were sent for cytology and parathyroid hormone (PTH) levels. All patients subsequently underwent parathyroid exploration.

RESULTS

54 patients underwent 57 ultrasound guided parathyroid biopsies. Indications for FNA included prior parathyroid (n = 29), thyroid (n = 11), or other neck surgery (n = 2), or unusual parathyroid appearance or location (n = 12). A true positive was defined as a site where the PTH aspirate was >40 pg/mL and a hypercellular gland was removed at surgery. Based on this, there were 44 true positives, 10 true negatives, and 3 false negatives; there were no false positives. The median PTH level in positive aspirates was 11,665 pg/mL. Cytology was primarily helpful in excluding other diagnoses.

CONCLUSION

Ultrasound guided FNA is a highly specific localization test for parathyroid tumors. This procedure can be successfully performed by surgeons in the office setting and is extremely valuable for directing parathyroid exploration in challenging cases. We recommend incorporating ultrasound and FNA as a pre-operative localization strategy for selected patients with HPT.

Validation study of intraoperative fine-needle aspiration of parathyroid tissue with measurement of parathyroid hormone levels using the rapid intraoperative assay

BACKGROUND

Surgical treatment of hyperparathyroidism relies on the ability to accurately identify parathyroid tissue. The use of intraoperative fine-needle aspiration (FNA) with measurement of intact parathyroid hormone level (iPTH-FNA) has been suggested as a useful adjunct and is evaluated in this pilot study.

METHODS

An institutional review board-approved retrospective review was performed on patients undergoing parathyroid exploration for primary hyperparathyroidism who also underwent selective FNA at the end of the procedure. FNA was performed on excised parathyroid tissue, ipsilateral thyroid tissue, and muscle.

RESULTS

Ten patients underwent FNA. Mean iPTH-FNA values were 1559.6 pg/mL (range, 675-1775) for parathyroid, 51.4 pg/mL(range, 10-248) for thyroid, and 34.1 pg/mL (range, 14-128) for muscle. All iPTH-FNA assay results were significantly higher for parathyroid tissue than for either thyroid tissue (P < 0.05) or muscle (P < 0.05). There were no significant iPTH-FNA assay differences between thyroid and muscle (P = 0.09).

CONCLUSIONS

Intraoperative FNA of parathyroid tissue with the rapid iPTH assay can correctly identify parathyroid tissue. It may prove to be a useful surgical adjunct in the treatment of hyperparathyroidism.

Fine needle aspiration and intraparathyroid intact parathyroid hormone measurement for reoperative parathyroid surgery

Some authors have praised the value of fine needle aspiration (FNA) with measurement of intraparathyroid intact parathyroid hormone (iPTH) for localization of the hypersecreting gland(s) in recurrent or persistent primary hyperparathyroidism (HPT). The aim of the present study was to determinate whether FNA for iPTH assay is an effective procedure to distinguish between normal and hypersecreting parathyroid glands. We performed a prospective study of 170 patients who underwent cervicotomy. They were divided into three groups: group A, 50 patients with thyroid diseases; group B, 100 patients with primary HPT; group C, 20 patients with secondary HPT. We performed intraoperative FNA for iPTH measurement from the thyroid, and from the normal and enlarged parathyroid glands, and we compared the different intraglandular iPTH assays. In group A, the intraparathyroid iPTH level was < 1000 pg/ml in 68% of the patients. In group B, in the pathological parathyroid gland iPTH was > 1000 in 88%; conversely, in the normal adjacent parathyroid glands it was < 1000 in 79%. In group C, intraparathyroid iPTH of enlarged glands was > 1000 in 80%. Intrathyroid iPTH was < 100 pg/ml in 96% for the three groups. We conclude that FNA for intraglandular iPTH measurement is an effective tool for distinguishing between normal and pathological parathyroid glands in the setting of primary HPT (p < 0.05), and between thyroid and parathyroid glands in groups A and B. But the procedure should be carried out in conjunction with the sestamibi scan and ultrasonography before surgical reintervention.

Ultrasound examination of the parathyroid glands

High-resolution sonography is a significant imaging tool available for evaluation of the parathyroid glands. It works particularly well in concert with nuclear imaging, especially in assisting preoperative localization of parathyroid lesions and in guiding interventional parathyroid procedures. Its limitations relate to anatomic areas not accessible to insonation. In the hands of an experienced examiner, it is a cost-efficient and important adjunct for the endocrine surgeon.

Challenges In Neck Ultrasonography: Lymphadenopathy And Parathyroid Glands

OBJECTIVE

To assess the performance of neck ultrasonography (US) in the detection of lymph node lesions metastatic from differentiated thyroid carcinoma (DTC) and the detection of parathyroid adenomas.

METHODS

Neck US was performed in 667 patients with DTC (173 men and 494 women; mean age, 47.7 years). In cases of suspicious neck nodes, US-guided fine-needle aspiration biopsy (US-FNAB) plus measurement of thyroglobulin in the needle washouts (FNAB-Tg) was done. In addition, 75 patients with primary hyperparathyroidism (pHPT) (15 men and 60 women; mean age, 56 years) underwent neck US and sestamibi scintiscanning for localization of parathyroid adenoma. For confirmation of US findings, US-FNAB plus measurement of parathyroid hormone in the needle washouts (FNAB-PTH) was performed. FNAB-PTH was also measured in 129 suspected parathyroid adenomas incidentally detected in a series of 4,129 patients undergoing neck US examination for thyroid disease.

RESULTS

The presence of DTC metastatic lesions was confirmed in 46 of 95 patients with suspicious neck nodes. US sensitivity and specificity were 82.1% and 91.2%, respectively. The positive predictive value (PPV) of US-FNAB + FNAB-Tg was 94.7%. In the 75 patients with pHPT, US followed by US-FNAB + FNAB-PTH showed a higher PPV (97.5%) in comparison with sestamibi scintiscanning (83.7%) in the detection of parathyroid adenoma. A parathyroid adenoma was also incidentally detected in 0.62% of the 4,129 patients undergoing neck US for thyroid disease.

CONCLUSION

US accurately detects DTC neck metastatic lesions and localizes parathyroid adenomas. Moreover, neck US may lead to discovery of parathyroid incidentalomas.

Detection and diagnosis of parathyroid incidentalomas during thyroid sonography

PURPOSE

The aim of our study was to evaluate the incidence of incidentally found parathyroid adenomas (incidentalomas) in patients undergoing sonography of the neck for thyroid disease.

METHODS

A total of 1,686 patients (305 men and 1,381 women) underwent sonography of the neck; the mean age was 49.6 +/- 21.7 years. In 38 patients (2.3%; 7 men and 31 women) with a mean age of 48.7 +/- 14.7 years, hypoechoic, homogeneous, oval nodules (mean volume, 1.0 +/- 0. 9 cm(3)) adjacent to the thyroid parenchyma were observed. All these lesions, compatible with the shape of an enlarged parathyroid gland, underwent ultrasound-guided fine-needle aspiration biopsy (FNAB), with measurement of parathyroid hormone (PTH) and thyroglobulin (Tg) levels in the needle washings (FNAB-PTH and FNAB-Tg). Biochemical screening for hyperparathyroidism was also performed.

RESULTS

Cytologic examination plus FNAB-PTH/FNAB-Tg measurements revealed the presence of cellular material consistent with parathyroid tissue in 9 patients (24%), thyroid tissue in 22 patients (58%), and lymphoid tissue in 4 patients (11%). A tissue diagnosis was not established in 3 patients (8%). Five of 9 patients with parathyroid enlargement had high serum PTH and calcium levels.

CONCLUSIONS

Enlarged parathyroid glands may be incidentally discovered during sonography of the thyroid. In patients with thyroid disease, the positive-predictive value of sonography in the identification of parathyroid tissue was low. Ultrasound-guided FNAB-PTH determination should be carried out when parathyroid adenoma is suspected. The incidental finding of an enlarged parathyroid may or may not be associated with yet undiagnosed hyperparathyroidism.