Localization studies in patients with hyperparathyroidism

Functional imaging for hyperparathyroidism

Once hyperparathyroidism has been proven, the goal of parathyroid functional imaging is to identify one or more pathological glands in view of guiding a possibly targeted surgical procedure, while maximizing the chances for recovery. Currently, parathyroid radionuclide imaging is based on two techniques, parathyroid scintigraphy and ¹⁸F-fluorocholine - positron emission tomography (PET). The main radiopharmaceutical in scintigraphy is ^99mTc-sestamibi, which can be used alone, in the dual-phase parathyroid scan, or in comparison with a thyroid radiotracer, pertechnetate (NaTcO₄) or iodine 123 (dual-tracer method). The acquisitions can be planar and/or tomographic (SPECT). It is now recognized that the ^99mTc-sestamibi - iodine 123 dual-tracer method is more efficient than the dual-phase scan, while SPECT-CT improves the sensitivity and specificity of the scintigraphy. This imaging and cervical ultrasonography are considered to be the two first-line reference techniques in preoperative assessment of hyperparathyroidism. More recently developed, ¹⁸F-fluorocholine detected by PET-CT has shown excellent performance, at least equal to that of scintigraphy. Initially considered as a second-line technique, its advantages over scintigraphy have prompted some authors to suggest it as the only examination to be performed in preoperative assessment of hyperparathyroidism. That said, due to a lack of specificity in ¹⁸F-fluorocholine uptake, which has been observed on inflammatory lesions and, particularly, in the mediastinal lymph nodes, and given the absence of simultaneous comparison of thyroid function, this strategy remains contested, and possibly reserved for patients without any associated thyroid pathology; large-scale evaluation would be justified.

Radioguided occult lesion localization for minimally-invasive parathyroidectomy without quick PTH monitoring and frozen section: impact of the learning curve

Objectives

Minimally-invasive parathyroidectomy (MIP) is a surgical procedure that reduces the duration of operation, hospital costs, and hypocalcemia, and shortens the length of hospital stay. This study addressed the important procedural details of the radioguided occult lesion localization (ROLL)-MIP technique and evaluated the consequences of the learning curve from a series of patients.

Patients and Methods

A total of 80 patients who underwent ROLL-MIP for a single parathyroid adenoma were included into this retrospective study. In order to analyze the effect of the learning curve, these subjects were then divided into 2 groups per time period and the operative times were compared. Group A consisted of 22 previously reported patients who served as the control group. Group B consisted of 58 consecutive patients.

Results

Serum calcium and parathyroid hormone (PTH) levels were normalized in all of the patients within 2 days and remained normal during the follow-up period (31 ± 18.5 months). None of the patients who underwent ROLL-guided parathyroidectomy suffered temporary or permanent recurrent laryngeal nerve injuries. Mean operation time (time from incision to excision of the adenoma) was 23 ± 6 min in Group A and 18 ± 7 min in Group B. Mean operative times were significantly shorter in group B.

Conclusion

The success of MIP administered with the ROLL technique in a single adenomatous patient was quite high. This method seems especially valuable in patients with atypically located or small adenomas.

Frequency of Preoperative Localization Techniques of Parathyroid Adenoma at King Abdulaziz University Hospital, Saudi Arabia

Background Accurate preoperative radiological localization of parathyroid pathologies paves the way to enable less invasive surgical procedures. Results on the accuracy of the different diagnostic measures are conflicting. Also, little is known about the most common location of parathyroid lesions. This paper aims to determine the most common location of parathyroid adenoma and evaluate the diagnostic performance of radiological modalities such as ultrasonography, sestamibi scintigraphy/single-photon emission computerized tomography (SPECT), magnetic resonance imaging (MRI), and computed tomography (CT) scan for the preoperative localization of parathyroid pathologies. Methods This is a retrospective study. Data were collected from patients who underwent total or partial parathyroidectomy at King Abdulaziz University Hospital between January 2000 and March 2020. The parathyroid adenoma site was detected preoperatively by a radiological method and confirmed postoperatively by the histopathology report. The performance of each preoperative localizing radiological method was evaluated based on the accuracy in localizing parathyroid pathology. Results A total of 73 patients were included in the analysis, with females being the most common gender in the study at 64%. Only complete data files were included and incomplete data files were excluded. The most frequent mode of detecting parathyroid adenoma was a sestamibi/SPECT scan (62.5%) followed by a CT scan (50%), ultrasound (34.6%), and MRI (25%). The most common location of a parathyroid adenoma was the left side. Conclusion Sestamibi/SPECT is a frequent radiological method for detecting the parathyroid lesion site as compared with CT, MRI, and ultrasonography.

Parathyroid Adenoma with Unusual Presentations of Rib Bone and Thoracic Vertebrae Fractures in a Premenopausal Female in Ibadan, Nigeria

Parathyroid adenoma is the most common cause of primary hyperthyroidism which leads to abnormal calcium homeostasis, hypercalcemia, and reduction in bone density. A 37-year-old female referred from a private health facility with a 1-year history of upper back swelling and pain. The pain was worse when sitting down for long periods and with movement and relieved by rest. There was no antecedent history of trauma, but the patient had noticed poor appetite and weight loss. There were no constipation, no abdominal discomfort, and no symptom suggestive of hyperthyroidism or hypothyroidism. General physical examination revealed kyphoscoliosis, and vital signs were within normal limits. Spine X-ray showed features of cervical spondylosis. Computed tomography (CT) scan and magnetic resonance imaging showed pathologic fractures of the right 9 ^thrib, anterior wedge compression, and reduction of T4 vertebrae with other abnormalities at T4-T5, T5-T6, T7-T8, T10-T11, and L4-L5 vertebrae. Bone marrow aspiration and serum electrophoresis were within normal limits. Serum calcium showed hypercalcemia. A CT scan of the neck was done which showed features of a right superior parathyroid adenoma. Blood count, other serum electrolytes, and thyroid function tests were all normal. A parathyroidectomy with right thyroid lobectomy was done. Histopathological examination of the resected parathyroid gland showed a diagnosis of parathyroid adenoma. A high index of suspicion is needed to diagnose this unusual presentation of parathyroid adenoma. Radiological imaging is an important tool for early diagnosis.

Parathyroid Pathology

Proliferative pathologic lesions of parathyroid glands encompass a spectrum of entities ranging from benign hyperplastic processes to malignant neoplasia. This review article outlines the pathophysiologic classification of parathyroid disorders and describes histologic, immunohistochemical, and molecular features that can be assessed to render accurate diagnoses.

Feasibility of Hyperfunctioning Parathyroid Gland Localization Using [18F]fluciclovine PET/CT

PURPOSE

To evaluate the ability of anti-1-amino-3-anti-1-amino-3-[¹⁸F]fluorocyclobutane-1-carboxylic acid ([¹⁸F]fluciclovine) positron emission tomography/X-ray computed tomography (PET/CT) in comparison to Technetium-99m 2-methoxy isobutyl isonitrile ([^99mTc]sestamibi) single-photon emission computed tomography/CT (SPECT/CT) for the localization of hyperfunctioning parathyroid glands in patients with hyperparathyroidism.

PROCEDURES

Four patients with hyperparathyroidism underwent 60-minutes sequential neck and thorax PET/CT after [¹⁸F]fluciclovine (352 ± 28 MBq) injection. Lesion uptake and target-to-background ratios (TBR) were compared with [^99mTc]sestamibi (798 ± 27 MBq) SPECT/CT in the same patient.

RESULTS

Both techniques detected 4/5 hyperfunctioning parathyroid glands identified at surgery. The highest [¹⁸F]fluciclovine uptake and TBRs were at 5-9 min with rapid washout. [^99mTc]sestamibi had significantly higher TBRs compared with [¹⁸F]fluciclovine (5-9 min) for blood pool (10.9 ± 4.7 vs 1.3 ± 0.6; p < 0.01) and reference muscle backgrounds (5.8 ± 3.0 vs 1.7 ± 0.6; p < 0.01), with non-significant trend for thyroid tissue background (1.3 ± 0.5 vs 1.1 ± 0.5; p = 0.73).

CONCLUSION

Hyperfunctioning parathyroid glands can be detected on [¹⁸F]fluciclovine PET/CT at early imaging, but conspicuity (TBR) is better with [^99mTc]sestamibi. [¹⁸F]fluciclovine PET/CT does not seem promising in the detection of hyperfunctioning parathyroid glands.

Ultrastructure of Hyperfunctioning Parathyroid Glands: Does it Explain Various Patterns of 99mTc-sestamibi Uptake

The aim of this study was to correlate the uptake of ^99mTc-methoxy-isobutyl-isonitrile (MIBI) with ultra-structural features of parathyroid adenomas. Twenty patients with proven primary hyperparathyroidism were evaluated prospectively. Preoperative double-phase ^99mTc-MIBI scintigraphy was performed in all patients and the degree of tracer uptake by the parathyroid lesions was assessed visually and semi-quantitatively. The excised glands were examined histologically and ultrastructurally, and their features were correlated with the degree of the radiotracer uptake. At surgery, 21 parathyroid adenomas were removed (double adenoma in one patient and a solitary adenoma in each of the remaining 19 patients). ^99mTc-MIBI scan detected 18 of the 21 adenomas. There was positive correlation between the degree of ^99mTc-MIBI uptake and the mitochondrial contents of the parathyroid adenoma cells. Four adenomas with intense uptake had high content of mitochondria in the cells. The three false-negative scans had low-to-moderate mitochondrial content. ^99mTc-MIBI uptake is related to the mitochondrial content of the parathyroid adenoma cells.

Serial pathologic fractures of five long bones on four separate occasions in a patient with primary hyperparathyroidism, challenges of management in a developing country: a case report

Multiple pathologic fractures secondary to parathyroid adenoma is rarely recognized and reported in the tropics. Inadequate evaluation causes worsened disability and increased psychological stress. We present a 27-year-old Nigerian male student with recurrent unexplained pathological fractures of the long bones. Primary Hyperparathyroidism was later diagnosed and he benefited from a unilateral parathyroidectomy. Primary hyperparathyroidism secondary to parathyroid adenoma is difficult to diagnose and needs a high index of suspicion. Surgery and good post-operative biochemical control of serum calcium produce satisfying outcomes.

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.

Hormone, relationships of parathyroid gamma counts, and adenoma mass in minimally invasive parathyroidectomy

OBJECTIVE

To better understand relationships of parathyroid hormone (PTH) production, adenoma gamma counts, and adenoma mass in patients undergoing minimally radioguided invasive parathyroidectomy for primary hyperparathyroidism from single-gland disease.

STUDY DESIGN

A prospective review of 104 patients operated on by a single surgeon.

SETTING

University tertiary hospital.

SUBJECTS

Adults who have primary hyperparathyroidism due to a single gland.

RESULTS

There were 23 men and 81 women with an average age of 63 years. The mean (SD) adenoma mass was 0.78 (0.69) g (median, 0.57 g). The mean (SD) percent of background for the adenoma was 120.2 (90.5). Preoperative PTH and percent of background gamma count of the adenoma showed a likely correlation with a Spearman ρ value of 0.2039 and a P value of .037. There were significant correlations between both percent of background of the adenoma and adenoma mass (Spearman ρ = 0.4991 and P < .0001). Preoperative PTH and adenoma mass also showed a significant positive correlation (Spearman ρ = 0.308 and P = .002).

CONCLUSION

There exist correlations between gland mass, radioactivity, and PTH level. Adenoma radiation counts do not appear to be a proxy for changes in PTH levels measured during surgery as has been reported. Intraoperative PTH has been shown by others not to be necessary when doing radioguided parathyroid surgery if the Norman rule is observed. However, a radioguided technique and intraoperative PTH can provide complementary information in making an assessment of completion of parathyroid procedures.

Parathyroid gland anatomical distribution and relation to anthropometric and demographic parameters: a cadaveric study

Parathyroid glands play an important role in controlling calcium levels, which influence muscular contraction and neurotransmission. The number of variants, localization and ectopic positions make these glands tricky during surgical exploration. Detailed anatomical knowledge of these glands is fundamental to avoid postsurgical hypoparathyroidism, such as failures during thyroidectomy and parathyroid procedures. The purposes of this work were to study and report practical knowledge for surgeons in order to localize the glands. Dissections were performed on 56 cadavers. Gland identity was confirmed by histological study. Also, mediastinal tissue and the carotid sheath were treated with Carnoy's solution to identify ectopic glands. The thyroid gland was divided and sliced to identify parathyroid glands in the parenchymal and subcapsular space. Four or more parathyroid glands were found in 89.3% of the studied specimens. Mean gland weight was 33.1 mg, and its mean measurements were 6.7 × 3.9 × 2.0 mm. In more than 90% of the cases there was a correlation with the inferior laryngeal nerve and the parathyroid glands: the upper glands were located in medial positions, and the lower ones were found to be located laterally. In 42.8% of cases at least one ectopic gland was observed. The main ectopic regions were the mediastinum and thymus (19.6%), thyroid subcapsular space (12.5%) and thyroid parenchyma (5.4%). Quantity, gland characteristics and location were not influenced by anthropometric and demographic parameters. Here we show the high incidence of parathyroid glands positioned at "abnormal" locations, and as a controversial topic in endocrine surgery, this matter must be continuously studied and reported in the literature.

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.

Primary hyperparathyroidism: retrospective 10-year study of 32 cases

BACKGROUND

Parathyroid glands are endocrine glands that regulate calcium metabolism. Usually four in number, they lie mostly on the posterior aspect of thyroid glands. Primary hyper-parathyroidism (PHPT) refers to a condition wherein they secrete an excess of parathyroid hormone leading to signs and symptoms of hypercalcemia.

PATIENTS AND METHODS

Thirty-two patients of primary hyper-parathyroidism were seen by us in the ten years. Majority of patients were below 40 years of age (88%). Male: female ratio was 1:4. The diagnosis was made incidentally in patients who reported for various signs and symptoms not responding to treatment. High serum calcium pointed to the diagnosis of primary parathyroid hyperplasia. It was confirmed by high level of serum parathyroid hormone and localization of enlarged parathyroid glands by USG / MRI and / or Tc-99 Technetium scan. Of the 32 patients examined, 43 parathyroid glands were excised, five cases had two glands excised; out of these 4 cases underwent parathyroid reimplantation in neck/forearm muscles. One unusual case underwent operation for giant-cell tumor of the head of humerus. This patient presented with excessive vomiting not responding standard medical management in post-operative period.

RESULTS

During investigations serum calcium was found to be very high, the diagnosis was confirmed by finding high parathyroid hormone and corroborated by T(99) Technetium scan. Parathyroidectomy was done in all cases, of which 59% (18 cases) developed mild to severe tetany due to hypocalcaemia.

CONCLUSION

Primary hyperplasia of thyroid gland is the most important cause of hypercalcemia. Hypercalcemia is found in all cases of PHPT in our series with high parathyroid hormone levels. Majority of our cases have one gland involvement and hypocalcaemia in our series is unusually high following excision of involved gland.

Scintigraphic techniques in primary hyperparathyroidism: from pre-operative localisation to intra-operative imaging

INTRODUCTION

Primary hyperparathyroidism (PHPT) is an increasingly diagnosed disease worldwide. In most cases, PHPT is related to the presence of a solitary parathyroid adenoma (PA). Fifty percent or more of newly diagnosed PHPT patients are asymptomatic, and there is debate among endocrinologists and endocrine surgeons about whether or not such patients should be treated.

LOCALIZATION

Usually, in a PHPT patient with a solitary PA that is well localised pre-operatively, a parathyroidectomy with limited or minimally invasive neck exploration is offered. The diffusion of minimally invasive neck exploration procedures is a consequence of the significant improvement in the accuracy of pre-operative imaging (mainly scintigraphic) techniques; these techniques have changed the surgical strategy to PHPT, from the wide traditional bilateral neck exploration to limited neck exploration.

REVIEW

The present review considers developments during the past 10-15 years with regard to both the accuracy of pre-operative localising imaging techniques and intra-operative minimally invasive procedures in order to provide endocrinologists and endocrine surgeons with further information about the newly available diagnostic and therapeutic tools for use in PHPT patients with a solitary PA.

Surgeon-Performed Ultrasound for Preoperative Localization of Abnormal Parathyroid Glands in Patients with Primary Hyperparathyroidism

BACKGROUND

The introduction of portable ultrasound equipment enables surgeons to perform ultrasound examinations in a clinic setting. This study was undertaken to evaluate surgeon-performed ultrasound (SP-US) in patients with primary hyperparathyroidism (PHPT).

METHODS

Between July 2003 and March 2004, 65 patients with PHPT were evaluated with SP-US and 48 of these patients underwent parathyroid surgery. Among this group of 48 evaluable patients, 47 had preoperative imaging with technetium-99m sestamibi scanning (MIBI), and 12 had an additional ultrasound examination at an external radiology department (RP-US).

RESULTS

All patients were cured of PHPT and the operative findings were used to determine the true status of the parathyroid glands of each patient. Twenty-four (50%) patients had concomitant thyroid nodules which were identified by SP-US, and 4 (8.3%) patients had simultaneous thyroid operations, 2 of which were for thyroid cancer. Considering data for all patients, SP-US had significantly higher sensitivity than MIBI or RP-US (60% vs. 46%, P = 0.013, and 60% vs. 11%, P = 0.004 respectively). Among the patients with a single adenoma, SP-US, MIBI, and RP-US had sensitivities of 83%, 63%, and 13% respectively. The specificities of all three imaging techniques were uniformly high and were not significantly different from each other.

CONCLUSIONS

Surgeon-performed ultrasound is an accurate modality for localizing abnormal parathyroid glands in patients with PHPT, with results that compare favorably with other parathyroid imaging modalities.

Localizing hyperfunctioning parathyroid tissue: MRI or nuclear study or both?

The surgical approach to primary hyperparathyroidism patients has changed recently with minimally invasive surgery becoming more common. This retrospective study reviews the relative sensitivities of dual-phase sestamibi (DP-SI) and magnetic resonance imaging (MRI) in preoperative patients. We found that MRI was more sensitive, but the difference was not statistically significant. Magnetic resonance imaging enhanced the ability to localize abnormal tissues when the DP-SI was negative. Together, both tests demonstrated a sensitivity of 92%. We recommend performing DP-SI initially, and if negative, MRI. This should provide the highest imaging sensitivity at the lowest cost.

Lateral minimal parathyroidectomy: safety and cosmetic benefits

BACKGROUND

Surgery has been the cornerstone of treatment for primary hyperparathyroidism for almost three decades. The recent application of state-of-the art imaging technologies to localize hyperfunctioning adenomas preoperatively has enabled surgeons to minimize the surgical procedure, reduce total operation time and improve cosmetic results without compromising the cure rate.

STUDY DESIGN

Twenty-one patients with a diagnosis of primary hyperparathyroidism were selected for treatment with the lateral minimal parathyroidectomy approach following preoperative imaging with ultrasonography, Tc-sestamibi scan, or both. All patients were followed during hospitalization and for three months after for calcium levels and cosmetic results.

RESULTS

The procedure was performed by the same surgical team for all 21 patients; under general anesthesia in 20 patients and under deep sedation in 1 patient at high surgical risk. In all cases, parathyroid adenoma was accurately localized by at least one of the imaging modalities before surgery: ultrasonography in 16 patients (76%), Tc-sestamibi scan in 15 (71%), and both in 10 (48%). Average total operative time for the lateral minimal invasive approach was 46 minutes (range 30-65 minutes). Blood calcium levels returned to normal in all patients, and cosmetic results were graded good to excellent.

CONCLUSIONS

With accurate preoperative localization of unilateral parathyroid adenoma by any imaging modality and careful patient selection, lateral minimal parathyroidectomy performed by a skilled surgeon may serve as a safe, effective procedure with good clinical and aesthetic outcomes.

Ultrasound in head and neck surgery: thyroid, parathyroid, and cervical lymph nodes

Ultrasound (US) of the neck is extremely sensitive in detecting thyroid, parathyroid, and cervical lymph node pathology, and is regarded as the most complete and cost-effective imaging method for evaluating the thyroid and parathyroid glands, as well as for the diagnostic evaluation of the cervical lymph node basin. US is widely used in screening high-risk individuals, evaluation of palpable and nonpalpable thyroid nodules, needle guidance for biopsy of nonpalpable and suspicious nodules, and preoperative evaluation of the extent of thyroid neoplasms, as well as in the detection of residual, recurrent, or metastatic thyroid tumors, and in observing nonsurgical cases. It has thus become an important adjunct to the practice of head and neck surgery.

Effects of prior neck radiation therapy on clinical features of primary hyperparathyroidism and associated thyroid tumors

OBJECTIVE

To compare the clinical and biochemical features, bone densitometry data, and results of diagnostic imaging to localize parathyroid tumors in patients with radiation-associated hyperparathyroidism (R-HPT) and patients with HPT who had no history of radiation exposure (NR-HPT).

METHODS

We performed a retrospective analysis of 34 patients with HPT who underwent evaluation and subsequent neck exploration between 1990 and 1995. We recorded and compared the symptoms, biochemical findings, bone densitometry data, results of diagnostic imaging, and pathologic findings in R-HPT and NR-HPT groups.

RESULTS

The R-HPT group (8 men and 4 women)generally was older than the NR-HPT group (14 men and 8 women), but the age difference was not statistically significant. Patients in the R-HPT group had received radiotherapy (6.9 to 21.7 Gy) between 2 and 9 years of age for various diagnoses. Eight patients (67%) in the R-HPT group and 13 (59%) in the NR-HPT group had no symptoms of HPT. The rest of the patients in both groups had nonspecific symptoms, such as fatigue and dyspepsia. Four patients (18%) in the NR-HPT group had nephrolithiasis, and 3 (14%) had skeletal manifestations at initial assessment. Serum calcium, phosphorus, and parathyroid hormone levels and 24-hour urine calcium excretion were similar in both groups. Mean lumbar spine bone mineral density was lower in women in the R-HPT group than in those in the NR-HPT group, but the prevalence of osteoporosis did not differ significantly in the two study groups. Sestamibi scintigraphy accurately localized adenomas in both groups equally well (sensitivity >90%). In the R-HPT group, 11 patients had a single parathyroid adenoma and 1 had hyperplasia of all four parathyroid glands. In the NR-HPT group, 21 patients had a single parathyroid adenoma and 1 had parathyroid hyperplasia. In nine patients in the R-HPT group, ultrasonography showed thyroid nodules >1 cm. Pathologic examination of surgical specimens in the R-HPT group confirmed thyroid carcinoma in 11 patients ( 10 papillary and 1 follicular can-cer); no patient in the NR-HPT group had thyroid cancer. Six weeks after thyroidectomy, patients with thyroid can-cer received 1311 (mean dose, 145 mCi), five of whom needed additional 1311 treatments.

CONCLUSION

Patients with a history of childhood neck irradiation who have HPT have a high likelihood of coexisting thyroid cancer. This observation may justify surgical exploration rather than vigilant follow-up in asymptomatic patients with primary HPT and coexisting thyroid nodules who have a history of radiation exposure.

Current issues in hyperparathyroidism

There has been a shift in the referral patterns in recent years that has resulted in increasing numbers of patients being referred to surgeons with a diagnosis of hypercalcemia rather than primary hyperparathyroidism. The surgeon must perform a thorough history, including medications, and laboratory assessment, including serum calcium and parathyroid hormone measurements. A 24-hour urinary calcium excretion should be routinely ordered to exclude FHH. After the diagnosis of primary hyperparathyroidism is made, preoperative localization studies will benefit 78% to 90% of patients, with sestamibi scan being the most commonly used.

Clinical outcomes and fiscal consequences of bilateral neck exploration for primary idiopathic hyperparathyroidism without preoperative radionuclide imaging or minimally invasive techniques

BACKGROUND

Radionuclide imaging-directed, minimally invasive parathyroid operation is promoted in the surgical literature and public domain as the fastest, most successful, and cheapest means of treating primary idiopathic hyperparathyroidism. The validity of these claims is unproven. This study reviews the treatment outcome results of a large series of patients treated with standard parathyroid operation without preoperative localization studies. Cost comparisons are made between this series and previous reports of selected patients in whom preoperative radionuclide imaging preceded minimally invasive parathyroid operation.

METHODS

Diagnosis, treatment, and outcome data for 688 consecutive patients undergoing first neck exploration for primary idiopathic hyperparathyroidism were prospectively collected. All patients in our series underwent standard bilateral neck exploration without preoperative localization studies. Intraoperative methylene blue was used to aid identification of all parathyroid glands. Surgical findings, pathological diagnosis, operative time, length-of-stay, and treatment success data were collected. Cost data were calculated for our series using the identical calculations used in previous reports. Our outcome and calculated cost data were compared with previous reports by centers advocating scan-directed, minimally invasive parathyroid operation.

RESULTS

Of 2,752 predicted total glands, 2,520 (91.6%) were identified using standard neck exploration without radionuclide localization studies. Single adenoma, with at least 1 normal gland, was found in 542 patients (78.8%), with 8 in a fifth gland. Multiple-gland hyperplasia was identified in 98 patients (14.2%) and of these 22 (3.2%) were double adenomas. Ten patients had parathyroid carcinoma (1.5%), and all received definitive surgical treatment during the primary operation. Cure rates were assessed by measurement of normal serum calcium and parathyroid hormone levels at 3 and 12 months after operation, and were 97.7% in our series. Mean operating time for the entire series was 65 minutes, decreased to 35 minutes in patients with single adenomas, and mean recovery room time was 30 minutes. Mean total costs for patients undergoing standard exploration for single adenoma was US dollars 1,107, and increased to US dollars 1,243 when patients with multigland disease, hyperplasia, or malignancy were included.

CONCLUSIONS

Our series demonstrates operative times and treatment outcomes with costs that are approximately one-third less than those for scan-directed, minimally invasive operation for primary idiopathic hyperparathyroidism. Thus, claims that scan-directed parathyroid operation is the cheapest, fastest, and most successful means of treatment are not supported by these data.

Pre-operative localization of parathyroid adenomas: a comparison of power and colour Doppler ultrasonography with nuclear medicine scintigraphy

AIM

To compare power and colour Doppler ultrasonography (US) with nuclear medicine scintigraphy (NM) in the preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT).

MATERIALS AND METHODS

Thirty-one patients with biochemical evidence of PHPT underwent pre-operative US and NM for parathyroid adenoma localization. Both studies were interpreted independently without prior knowledge of the other study's findings. All patients had surgical removal of the parathyroid adenoma utilizing standard neck exploration or minimally invasive unilateral surgical techniques with rapid serum assay of circulating parathyroid hormone levels.

RESULTS

All patients had single parathyroid adenomas at surgery. Prospective sensitivities for US, NM and both studies combined were 65%, 68%, and 74%, respectively, with a positive predictive value of 100% each. The adenoma was localized by only one imaging modality in 16% of cases.

CONCLUSIONS

US and NM provide complementary roles in the pre-operative localization of parathyroid adenomas in patients with PHPT.

Neuroendocrine tumor markers

Tumor markers used in the diagnosis and follow-up of patients with neuroendocrine tumors are in most instances not specific for a given tumor and circulate under normal conditions in the serum, making their use as an early diagnostic tool difficult (low sensitivity). By combining hormone measurements with tissue responsiveness, demonstrations of inappropriate secretions of PTH, insulin, and gastrin during hypercalcemia, hypoglycemia, and hyperacidity, respectively, become highly sensitive and specific diagnostic tests. The application of polyclonal antibodies in RIAs of hormones, such as ACTH, insulin, and gastrin, increase the diagnostic level of hormone measurements in patients with neuroendocrine tumors. Other markers, such as chromogranin A, neuron-specific enolase, and alpha-subunit, as well as peptide receptor visualization, are of increasing importance in the diagnosis and follow-up of neuroendocrine and non-neuroendocrine tumors.

Can localization studies be used to direct focused parathyroid operations?

BACKGROUND

There is considerable controversy today concerning the most appropriate surgical approach for patients with primary hyperparathyroidism. The conventional surgical operation involves a bilateral neck exploration through a collar incision with identification of all parathyroid tissue and removal of abnormal parathyroid glands while the patient is under general anesthesia. The success rate of this operation is about 95% or greater in the hands of an experienced endocrine surgeon. Preoperative localization techniques are generally considered to be unnecessary before initial parathyroid operations. The purpose of this investigation was (1) to evaluate the individual and combined accuracy of ultrasonography and technetium 99m sestamibi scans in localizing abnormal parathyroid glands and (2) to determine whether such scans could be used to direct a focused operation.

METHODS

We retrospectively studied 338 patients with sporadic primary hyperparathyroidism who had preoperative neck localization studies, ultrasonography and/or technetium 99m sestamibi scans, and parathyroid exploration (238 patients or, reexploration, 60 patients) from January 1996 to April 2000 at the University of California San Francisco/Mount Zion Medical Center. The preoperative localization studies were recorded as true-positive, false-positive, and false-negative and compared with the surgical and pathologic findings and with the outcome of the operation.

RESULTS

All of the abnormal parathyroid glands were correctly identified by ultrasonography in 184 of 303 patients (60.7%) and by technetium 99m sestamibi scanning in 183 of 237 patients (77.2%). The sensitivities of ultrasonography and sestamibi were 65% and 80%, respectively. Among the 202 patients who received both ultrasonography and sestamibi scans, a parathyroid tumor was identified at the same site in 105 (52%) of them. When both techniques identified a parathyroid tumor at the same site, the tests were correct in 101 of 105 patients and the sensitivity increased to 96%.

CONCLUSIONS

When both the ultrasonography and sestamibi scans identified the same, solitary parathyroid tumor in patients with sporadic primary hyperparathyroidism, this was the only abnormal parathyroid gland in 96% of the patients. A focused parathyroidectomy could therefore be performed in such patients with an acceptable ( approximately 95%) success rate.

Risk of Parathyromatosis after Fine-Needle Aspiration

Reoperative surgery for hyperparathyroidism (HPT) is fraught with hazard. When preoperative imaging studies are inconclusive or patient comorbidities are extensive fine needle-aspiration (FNA) is helpful to confirm the presence of suspected parathyroid tissue in the neck. Some surgeons refrain from using FNA because of the concern of tissue implantation (parathyromatosis). A retrospective review (1984–1996) of all patients diagnosed with HPT undergoing FNA of suspected parathyroid tissue was performed to document whether a correlation exists between FNA of suspected parathyroid tissue and subsequent development of parathyromatosis. Parathyromatosis was considered to have occurred when proven by histology or suspected on the basis of clinical studies. Of 81 patients with HPT undergoing ultrasound-guided FNA to assess abnormalities in the neck 41 patients with confirmed parathyroid tissue were identified. The indications for FNA in these 41 patients were: prior failed cervical exploration (n = 33), prior neck surgery and/or radiation (n = 2), inconclusive noninvasive imaging studies (n = 15), and severe comorbidities (n = 8). Mean follow-up was 5.8 years. No case of FNA-induced parathyromatosis was identified. FNA is useful to confirm the presence of parathyroid tissue in very select patients with hyperparathyroidism. FNA often eliminates the need for other imaging studies, may prevent a needless or likely fruitless re-exploration, and does not cause parathyromatosis.

Comparison between MR imaging and 99mTc MIBI scintigraphy in the evaluation of recurrent of persistent hyperparathyroidism

PURPOSE

To compare the sensitivity and positive predictive value of magnetic resonance (MR) imaging and technetium 99m 2-methoxyisobutyl-isonitrile (MIBI) scintigraphy for the detection of hyperfunctioning parathyroid tissue when used alone and in combination in a large patient population with recurrent or persistent hyperparathyroidism (HPT).

MATERIALS AND METHODS

In 98 consecutive patients with biochemically proved recurrent or persistent HPT after surgery, MR imaging and 99mTc MIBI study findings were retrospectively reviewed and compared with surgical and histopathologic findings. The sensitivity and positive predictive value of MR imaging and 99mTc MIBI scintigraphy were compared with each other and in combination.

RESULTS

In these patients, 130 abnormal parathyroid glands were identified at surgery. The sensitivity and positive predictive value of MR imaging were 82% (95% CI: 75%, 89%) and 89%, respectively; those for (99m)Tc MIBI scintigraphy were 85% (95% CI: 79%, 91%) and 89%. No significant difference was found between MR imaging and 99mTc MIBI scintigraphy for sensitivity (P =.7). The sensitivity and positive predictive value for the detection of abnormal parathyroid tissue on a per-gland basis increased to 94% (95% CI: 90%, 98%) and 98%, respectively, when only one of the two tests was required to be positive.

CONCLUSION

MR imaging and 99mTc MIBI scintigraphy have similarly good sensitivity and positive predictive value for the detection of hyperfunctioning parathyroid tissue in patients after surgery. The combination of the two tests provided a substantial increase in sensitivity and positive predictive value.

Efficacy of preoperative dual-phase sestamibi scanning in hyperparathyroidism

PURPOSE

The objective of this article is to evaluate our experience with sestamibi scanning in patients with primary and secondary hyperparathyroidism.

PATIENTS AND METHODS

A retrospective review of patients referred to the radiology department at the University of Kansas Medical Center for parathyroid studies between January 1, 1993, and August 1, 1998, was done. Patients included in the study were those who underwent both dual-phase technetium (Tc-99m) sestamibi scanning and subsequent parathyroidectomy at our institution (n = 34). Twenty-six patients had primary hyperparathyroidism and 8 patients had secondary hyperparathyroidism. Fifteen had previous history of neck exploration.

RESULTS

Sensitivity of sestamibi scans in detection of all abnormal pathology in cases of primary hyperparathyroidism was 60% overall. Among the subset of adenoma cases, sensitivity was 82% (14/17). Among cases of primary parathyroid hyperplasia, no scan correctly localized all abnormal glands; however 60% (3/5) showed localization of at least one hyperplastic gland. Of the 2 patients with parathyroid carcinoma, in only one case was there evidence of sestamibi retention in the correct thyroid lobe. In patients with secondary hyperparathyroidism, sestamibi scanning was successful in identifying all hyperplastic tissue in only one case (sensitivity 13%). In 7 of the 8 cases of secondary hyperparathyroidism, the scan localized at least one hyperplastic gland.

CONCLUSION

Sestamibi scanning is useful in the localization of abnormal pathology in cases of primary hyperparathyroidism, especially adenomas. In cases of hyperplasia, whether attributable to primary or secondary hyperparathyroidism, sestamibi imaging is less successful.

Ultrasound evaluation of the parathyroid glands in two hypercalcemic cats

Two parathyroid masses were identified using ultrasound in two hypercalcemic cats. The masses were identified as parathyroid adenomas on surgical biopsy. Both parathyroid masses contained hypoechoic regions with distal acoustic enhancement. Both masses were greater than 1.0 cm in diameter.

[Surgery for primary hyperparathyroidism in 1998. Apropos of 66 patients and 3 methods of approach]

STUDY AIM

The aim of this prospective study was to assess the advantages and disadvantages of cervicotomy, selective lateral approach and video-assisted surgery in the treatment of primary hyperparathyroidism (HPT 1).

PATIENTS AND METHODS

During 1998, 66 patients were operated on for HPT 1 in the same center. There were 48 women and 18 men (mean age: 58 years, range: 21-84), familial HPT 1 or MEN1 excluded. The interventions were performed via classical cervicotomy (n = 32), via selective lateral approach (n = 8) and were video-assisted (n = 25). A mediastinal adenoma was removed via cervicotomy and another one via left thoracoscopy. The procedure was associated with intraoperative parathormone (PTH) quick-assay. Calcium testing was controlled before leaving the hospital and 2 months later.

RESULTS

A double adenoma and 65 single adenomas were confirmed by pathological report. Circulating PTH levels, 20 minutes after removal of the adenoma, always decreased significantly. In video-assisted procedures, there were 11 conversions to open cervicotomy (44%) and morbidity consisted of one case of laryngeal nerve paralysis. At the end of the study, all patients except one had a normal calcium level.

CONCLUSION

Video-assisted parathyroidectomy is feasible but requires a preoperative localisation of the adenoma and intraoperative PTH quick-assay. Its main benefit in cervical adenoma is to reduce the scar and in mediastinal adenoma to avoid sternotomy. With the elective approach, results are similar to those of video-assisted surgery and the procedure is much easier to perform. Classical cervicotomy is still the best option in case of previous cervicotomy, of simultaneous thyroidectomy, of negative preoperative imaging and in elderly patients less concerned about cosmetic benefit.

Direct, minimally invasive adenomectomy for primary hyperparathyroidism: An alternative to conventional neck exploration?

OBJECTIVE

To evaluate the feasibility and efficacy of a direct, minimally invasive adenomectomy (MIA) as an alternative to conventional neck exploration (CNE) in patients with primary hyperparathyroidism.

SUMMARY BACKGROUND DATA

Because primary hyperparathyroidism is caused by a solitary adenoma in 85% to 90% of patients, a direct adenomectomy through a mini-incision would theoretically suffice whenever an adenoma is correctly localized on preoperative imaging. If effective, a less invasive method could spare the patient an unnecessary bilateral neck exploration, thus saving time and rendering future surgical procedures in the neck less problematic.

METHODS

Between October 1994 and October 1998, 110 consecutive patients with biochemically proven primary hyperparathyroidism who were to undergo surgery were enrolled in this study. Ultrasound and spiral CT were routinely performed as standard preoperative imaging modalities in the first series of 65 patients. In the second series of 45 patients, ultrasound was performed as the sole initial modality; it was supplemented by CT only in case of inconclusive test results. If test results were unequivocal (one adenoma), the patient was offered MIA. CNE was performed if the results were equivocal or if multiglandular disease was suspected.

RESULTS

Overall, 84 patients were selected for MIA and 26 for CNE. In the first series, 2 MIA procedures (2/51) were converted to CNE because of negative perioperative findings. All 65 procedures resulted in normocalcemia. In the second series, all but five (4/33 MIAs, 1/12 CNEs) resulted in normocalcemia. A reexploration (CNE) was performed in three patients, resulting in normocalcemia after resection of a second or third adenoma. Two patients are still awaiting reexploration. In both series together, 78 of the 110 patients were successfully treated with MIA and spared CNE.

CONCLUSION

MIA is a safe and effective alternative to CNE that may replace CNE in approximately two thirds of all patients.

Parathyroid glands: combination of (99m)Tc MIBI scintigraphy and US for demonstration of parathyroid glands and nodules

PURPOSE

To determine the appropriate choice of imaging techniques for localization of nodular lesions of parathyroid glands.

MATERIALS AND METHODS

First, computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US), and technetium 99m methoxyisobutyl-isonitrile (MIBI) scintigraphic images in 49 patients with primary hyperparathyroidism were retrospectively evaluated. A single-blind, prospective study that included 16 patients with primary hyperparathyroidism was then conducted. MR, US, scintigraphic, and color Doppler US images of the neck were obtained and analyzed.

RESULTS

In the retrospective study, CT, MR imaging, and US had low sensitivity (13%, 17%, and 27%, respectively) and specificity (39%, 65%, and 65%, respectively). Scintigraphy had 57% sensitivity and 85% specificity. In the prospective study, the use of latest-generation MR and US equipment and the participation of experienced operators led to improved sensitivity and specificity for these techniques. The combination of US and scintigraphy resulted in improved sensitivity (96%), specificity (83%), and positive and negative predictive values (88% and 94%, respectively), relative to the results obtained with either method alone. Doppler US was of little help in the setting of small glands.

CONCLUSIONS

The combination of (99m)Tc MIBI scintigraphy and US performed by well-trained operators with up-to-date instruments appeared to be the best diagnostic tool for the preoperative diagnosis of parathyroid disease.

Is sestamibi-guided parathyroidectomy really cost-effective?

BACKGROUND

Sestamibi-guided limited neck explorations are an alternative to the standard bilateral neck exploration for patients with primary hyperparathyroidism. A recently published meta-analysis by Denham and Norman (JACS vol.186, 1998) suggested that a sestamibi-directed approach offers a cost benefit because it decreases operative and recovery room times, hospital stay, and the number of frozen sections needed.

METHODS

We reviewed 41 bilateral neck explorations for primary hyperparathyroidism and compared our results with those reported by the meta-analysis to determine whether a sestamibi-directed approach is cost effective.

RESULTS

Operative and recovery room times averaged 60.3 +/- 19.3 and 45 minutes, respectively. Forty six percent of the patients were treated as outpatients, and 1.21 +/- 0.57 frozen sections were obtained per case. Our standard bilateral exploration cost 47% less than the bilateral approach and 17% less than the sestamibi-directed operation calculated in the meta-analysis. There were no cases of nerve injury or permanent hypocalcemia, 98% of patients were cured, and 61% of patients did not require narcotics postoperatively.

CONCLUSIONS

Sestamibi-guided parathyroidectomy may not offer any advantage over the standard bilateral exploration. In our experience, a bilateral neck exploration can be performed on an outpatient basis and at low cost, with a high success rate and minimal morbidity. Most patients do not require narcotics, and the cosmetic results are excellent.

Surgical therapy for primary hyperparathyroidism in patients with previous thyroid surgery

BACKGROUND

In patients with primary hyperparathyroidism (HPTH) and previous thyroid operations, complications of parathyroidectomy are more frequent than in patients undergoing initial neck surgery. The aim of this study was to investigate the value of preoperative imaging with regard to its influence on the surgical strategy.

METHODS

We retrospectively analyzed 17 patients with primary HPTH and previous thyroid surgery. Preoperatively 16 patients underwent sonography and/or scintigraphy.

RESULTS

Sonography had an overall accuracy to correctly localize enlarged parathyroid glands of 80%, and scintiscanning had overall accuracy of 78.6%. The accuracy of localization was increased up to 84.6% if both diagnostic procedures were applied. In patients with normal thyroid residues the accuracy of sonography was 85.7%, and it was 100% if scintiscanning was used.

CONCLUSIONS

Preoperative localization techniques in patients with primary HPTH and previous thyroid surgery have high accuracy. This allows for an imaging-directed operative strategy, thus preventing unnecessary bilateral neck explorations, which carry a high risk of recurrent laryngeal nerve injury.

Optimal imaging time for delayed images in the diagnosis of abnormal parathyroid tissue with Tc-99m sestamibi

PURPOSE

Double-phase scintigraphy with Tc-99m sestamibi is a good method to detect hyperfunctioning parathyroid glands. This study tried to determine the best time for delayed images: 2 or 4 hours.

METHODS

Fifty-six patients were studied, and 35 of them had primary hyperparathyroidism (mean age, 53 +/- 13 years; 54% were women). Cervical ultrasonography was performed on 29 of 56 (52%) patients and surgery in 16 of 56 (29%) patients. The dose was 740 MBq (20 mCi) given intravenously, and the acquisition was performed at 10 minutes, 2 h, and 4 h using anterior views, including the mediastinum. Studies that had positive results were analyzed blindly by two independent observers, who selected the best definition for abnormal activity.

RESULTS

Nineteen of 56 (34%) studies were negative and 37 of 56 (66%) were positive, 25 of them with one focus and 12 with two or more parathyroid foci. Analysis revealed 76% agreement between the observers (the rest was classified by consensus). In 70% of the cases, the best delayed image was obtained at 2 hours, in 16% at 4 hours (P < 0.00001), and in 14% both images were similar. In those cases with better images at 4 hours, the 2-hour images also showed the lesions. In two patients, lesions were seen only at 2 hours. These results could be explained by tracer decay, washout of parathyroid activity, or both.

CONCLUSIONS

The best protocol should include the early 10-minute image and the 2-hour delayed view. Further controls do not appear necessary. This may be important for patient throughput.

Parathyroid imaging with Tc-99m sestamibi planar and SPECT scintigraphy

Technetium-99m sestamibi planar and single-photon-emission computed tomographic scintigraphy is useful in the diagnosis of parathyroid gland disease. To understand the various patterns of parathyroid disease, it is important to understand parathyroid embryology and anatomy. The spectrum of parathyroid disease demonstrated with Tc-99m sestamibi scintigraphy includes eutopic disease, ectopic disease, solitary adenoma, double or multiple adenomas, cystic adenoma, lipoadenoma, multiple endocrine neoplasia, hyperfunctioning parathyroid transplant, entities with atypical washout, and nonparathyroid entities that take up Tc-99m sestamibi. The diagnosis of parathyroid tumors with Tc-99m sestamibi scintigraphy is based on the difference in clearance rates between the thyroid and diseased parathyroid glands, and any condition that interferes with radiotracer clearance will limit the effectiveness of the study. The technique is most clearly indicated for the preoperative evaluation of recurrent or persistent hyperparathyroidism, but it is increasingly being used before the initial surgical exploration as well. Subtraction Tc-99m sestamibi and iodine-123 scintigraphy may be helpful in difficult cases. Parathyroid hyperplasia, multisite parathyroid disease, and concomitant thyroid and parathyroid disease remain potential hurdles for this scintigraphic technique, and optimal handling of these problems still relies heavily on the skill and experience of the endocrine surgeon.

Radionuclide scanning in parathyroid diseases

BACKGROUND

New radionuclide agents and scanning procedures have markedly improved preoperative parathyroid gland localization. The aim of this review was to evaluate the results of parathyroid scanning and to clarify its current place in the clinical management of parathyroid diseases.

METHODS

The literature describing the different radioisotopes and available scanning techniques was analysed and their clinical outcome in various parathyroid diseases was evaluated.

RESULTS

Using 99mTc-radiolabelled sestamibi or other 9mTc-labelled cationic complexes, parathyroid scintigraphy detects 87 per cent of solitary adenomas (n=894), 55 per cent of abnormal glands in patients with multiglandular disease (n=303) and 75 per cent of persistent or recurrent lesions in patients with previous neck surgery (n=240). If necessary, three-dimensional imaging techniques can clarify the spatial localization of an ectopic uptake focus. The positive predictive value of the available scanning procedures is over 95 per cent, but false-positive uptake may be encountered.

CONCLUSION

Radionuclide parathyroid gland scanning with 99mTc-labelled cationic complexes is the initial non-invasive method of choice for preoperative parathyroid gland localization in patients at special risk and/or with previous neck exploration. While scanning has also been proposed to facilitate parathyroidectomy, there is no objective evidence to support its routine use before a first-time surgical procedure.

Parathyroidectomy via bilateral cervical exploration: a retrospective review of 866 cases

INTRODUCTION

Parathyroidectomy via cervical exploration is an effective primary-modality treatment for hyperparathyroidism, with cure rates of greater than 95%. We retrospectively reviewed 866 consecutive parathyroidectomies performed by a single surgeon between 1960 and 1997. We attempted to describe the polymorphic variation in multiglandular disease, the anatomic locations of pathologic glands, and the operative strategy and techniques which we believed were important to minimizing morbidity and maximizing curative success.

METHODS

The cases of 329 males and 537 females (age, 1-88 years) were reviewed. There were 766 operations performed: primary hyperparathyroidism (713), tertiary hyperparathyroidism (100), reoperations (53). The strategy for primary exploration includes a bilateral neck exploration, early recurrent laryngeal nerve skeletonization, and identification of at least four glands.

RESULTS

Normocalcemia was achieved in 98.2% of cases after initial cervical exploration. Persistent hypercalcemia occurred in 7 patients (<1%). Nine patients (1%) suffered persistent postoperative hypocalcemia. Unilateral recurrent laryngeal nerve injury occurred in two patients (<1%). Other perioperative complications included: reoperation for hematoma, repaired carotid artery injury, unexplained dysphagia, pneumothorax, deep venous thrombosis, and aspiration pneumonia. There were two mortalities (<1%) attributable to severe, comorbid disease. Ectopic glands were found in 120 cases. The frequency of glands at these sites were as follows: mediastinal (4.9%), intrathymic (8.4%), intrathyroid (6.7%), and retroesophageal/retrotracheal (3.5%). Thyroid resections provided diagnosis of concomitant thyroid carcinoma in 8.0% of resected patients. The pathology of patients with primary hyperparathyroidism (PHPT) consisted of single adenomas (77.2%), hyperplasia (21.0%), normal glands (1%), double adenomas (<1%), and parathyroid carcinoma (<1%). The distribution of adenomas was as follows: left upper, 25.3%; left lower, 27.3%; right upper, 26.8%; right lower, 20.6%. Hyperplastic glands were found in ectopic positions as follows: intrathymic (7.5%), intrathyroid (11.3%), mediastinal (2.5%), and retroesophageal/retrotracheal (0%). The average volume difference between the largest and smallest hyperplastic gland of each case was 1.80 + 4.40 cm3. Reoperations were performed upon 53 referred patients and 7 patients after failed exploration. Normocalcemia was attained in 98.3% of cases. Glandular pathology was identified in the previous operative field in 52 patients (86.7%). Adenomas were identified in 56.0% (n = 23) and hyperplasia in 39.0% (n = 16).

CONCLUSIONS

In our series, we were able to attain normocalcemia in 98.2% of cases after initial cervical exploration. We believe that identification of four glands, an exhaustive search of ectopic sites, bilateral exploration, and liberal use of biopsy and intraoperative frozen section were essential to curative success. The pathologist should identify parathyroid tissue in the specimen and differentiate the "abnormal" from "normal" gland. Morphologic criteria alone cannot be used because of polymorphic variation in hyperplasia in which pathologic glands may appear normal. Early identification of the recurrent laryngeal nerve allows for a safer neck exploration by alerting the surgeon to the location and course of the nerve. A bilateral approach does not contribute increased morbidity from recurrent laryngeal nerve injury.

Clinical profile of primary hyperparathyroidism in adolescents and young adults

OBJECTIVE

Primary hyperparathyroidism (PHPT) is an uncommonly diagnosed condition among adolescents and young adults. We review the clinical characteristics of these patients based on our institutional experience.

SUBJECTS

Patients aged 12-28 years treated for PHPT at our institution from 1990 to 1996 were evaluated by a review of medical records and current follow-up data. This consisted of 22 patients (8M:14F), constituting approximately 3% of all patients operated for PHPT during this period.

MEASUREMENTS

Serum and urinary calcium concentrations, renal function, and serum intact parathyroid hormone (IPTH) levels were measured in all patients. After biochemical confirmation of diagnosis, the patients completed a questionnaire to evaluate the presence of symptoms and/or conditions associated with PHPT. All the patients underwent parathyroidectomy and their tumour characteristics were evaluated. Surgical outcome was determined by measurements of serum calcium and IPTH levels postoperatively and during long-term follow-up.

RESULTS

A third of the patients were diagnosed by routine serum chemistry whereas two-thirds presented with symptoms or conditions associated with hypercalcaemia. Non-specific complaints such as fatigue or exhaustion, and weakness or lethargy constitute the most common findings on questionnaire review. A family history of PHPT was present in only 2 patients. The preoperative peak serum calcium levels ranged from 2.67 to 4.19 mmol/l (norm: 2.10-2.54 mmol/l), with a median of 3.07 mmol/l. Surgical pathologies revealed 59% solitary adenoma, 27% hyperplasia, 9% multiple adenomas and 5% carcinoma. Comparison between the adolescents (aged 12-18 years) and young adults (aged 19-28 years) revealed no differences in the clinical, pathological or laboratory profiles, except for a male predominance in adolescent patients. Fifteen patients had resection of one or more adenomas while 7 underwent subtotal parathyroidectomy. Six patients (27%) were reoperated cases, all received primary treatment elsewhere. All patients with benign PHPT were cured surgically, with a median follow-up of 47 months (range 3-77 months). One reoperated patient developed permanent hypocalcaemia. One patient with carcinoma underwent several operations for recurrence; he is now eucalcaemic despite persistent disease at 80 months from diagnosis.

CONCLUSIONS

We found a high incidence of multiglandular disease and relatively non-specific symptomatology in our adolescent and young adult patients with primary hyperparathyroidism. In view of the heterogeneous clinical expression noted in young patients, one should consider primary hyperparathyroidism in the differential diagnosis of unexplained non-specific complaints, and perform serum calcium estimations more readily in these subjects. Our experience suggests that primary hyperparathyroidism can be a serious disease with significant morbidity if left untreated, whereas parathyroidectomy provides successful results.