Preoperative sestamibi scanning and surgical findings at bilateral, unilateral, or minimal reoperation for recurrent hyperparathyroidism after subtotal parathyroidectomy in patients with multiple endocrine neoplasia type 1

Management of familial hyperparathyroidism syndromes: MEN1, MEN2, MEN4, HPT-Jaw tumour, Familial isolated hyperparathyroidism, FHH, and neonatal severe hyperparathyroidism

While primary hyperparathyroidism (PHPT) generally represents a common endocrine disorder, being the more frequent cause of hypercalcemia in outpatients, familial forms of PHPT (FPHPT) account for no more than 2-5% of the overall PHPT. In the last decades, many technical progresses in both molecular and biochemical-radiological evaluation have been made, and substantial advancements in understanding these disorders have been reached. Differences both in the pathogenesis and clinical presentation exist among the various hyperparathyroid syndromic forms, and, since FPHPT is frequently associated to other endocrine, proliferative and/or functional disorders, as also non-endocrine tumours, with varying clinical spectrum of occurrence in each syndrome, its early clinically detection for appropriately preventing complications (i.e. kidney and bone disorders) is strictly advised. In this review, the clinical-biochemical features and diagnostic procedures of each FPHPT form will be summarized and a general overview on surgical and pharmacological approaches to FPHPT has been also considered.

The future: diagnostic and imaging advances in MEN1 therapeutic approaches and management strategies

Prospective randomized data are lacking, but current clinical expert guidelines recommend annual screening examinations, including laboratory assessments and various imaging modalities (e.g. CT, MRI, scintigraphy and EUS) for patients with multiple endocrine neoplasia type 1 (MEN1). Routine screening is proposed to detect and localize neuroendocrine manifestations as early as possible. The goal is timely intervention to improve quality of life and to increase life expectancy by preventing the development of life-threatening hormonal syndromes and/or metastatic disease. In recent years, some studies compared different and new imaging methods regarding their sensitivity and utility in MEN1 patients. This present article reviews the proposed diagnostic tools for MEN1 screening as well as potential future perspectives.

Persistent and recurrent hyperparathyroidism

Despite remarkable progress in imaging modalities and surgical management, persistence or recurrence of primary hyperparathyroidism (PHPT) still occurs in 2.5-5% of cases of PHPT. The aim of this review is to expose the management of persistent and recurrent hyperparathyroidism. A literature search was performed on MEDLINE using the search terms "recurrent" or "persistent" and "hyperparathyroidism" within the past 10 years. We also searched the reference lists of articles identified by this search strategy and selected those we judged relevant. Before considering reoperation, the surgeon must confirm the diagnosis of PHPT. Then, the patient must be evaluated with new imaging modalities. A single adenoma is found in 68% of cases, multiglandular disease in 28%, and parathyroid carcinoma in 3%. Others causes (<1%) include parathyromatosis and graft recurrence. The surgeon must balance the benefits against the risks of a reoperation (permanent hypocalcemia and recurrent laryngeal nerve palsy). If surgery is necessary, a focused approach can be considered in cases of significant imaging foci, but in the case of multiglandular disease, a bilateral neck exploration could be necessary. Patients with multiple endocrine neoplasia syndromes are at high risk of recurrence and should be managed regarding their hereditary pathology. The cure rate of persistent-PHPT or recurrent-PHPT in expert centers is estimated from 93 to 97%. After confirming the diagnosis of PHPT, patients with persistent-PHPT and recurrent-PHPT should be managed in an expert center with all dedicated competencies.

Reoperative Surgery in Patients with Multiple Endocrine Neoplasia Type 1 Associated Primary Hyperparathyroidism

BACKGROUND

Persistent/recurrent primary hyperparathyroidism (pHPT) occurs frequently in multiple endocrine neoplasia type 1 (MEN1). We assessed the usefulness of intraoperative PTH (IOPTH) and preoperative localizing studies based on the outcome of patients with MEN1-associated pHPT undergoing reoperative surgery.

METHODS

A retrospective analysis identified MEN1 patients with persistent/recurrent pHPT. Patient outcome was defined as postoperative serum calcium and PTH levels (cured, persistent or recurrent) at last follow-up. Positive predictive value (PPV) was calculated for imaging studies and IOPTH.

RESULTS

Thirty patients with MEN1-associated recurrent/persistent pHPT underwent 69 reoperative parathyroidectomies. Median follow-up time was 33 months. Persistent pHPT occurred in four (13 %) patients. IOPTH had a 92 % PPV for postoperative eucalcemia. Ultrasound and Tc99m-sestamibi had sensitivities of 100 and 85 % for localizing an enlarged parathyroid gland. However, five (17 %) patients had additional enlarged glands, not visualized preoperatively that were removed after IOPTH did not drop appropriately. Bone mineral density scores did not improve after reoperation (p = 0.60), but the rate of postoperative nephrocalcinosis did (p = 0.046). Patients with pancreatic neuroendocrine tumors had significantly higher rates of persistent/recurrent pHPT compared with those without (40 vs. 0 %, p = 0.021). Intraoperative and delayed parathyroid autotransplantation was performed in nine (30 %) and four (14 %) patients, respectively.

CONCLUSIONS

Although preoperative localizing studies are helpful for guiding reoperative strategy in MEN1 with persistent/recurrent pHPT, additional enlarged glands may be missed by conventional imaging. IOPTH should therefore be employed routinely in this setting. Routine cryopreservation should be considered in all patients. Pancreatic manifestation may be associated with earlier recurrence or persistent disease.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.

Causes and treatment of recurrent hyperparathyroidism after subtotal parathyroidectomy in the presence of multiple endocrine neoplasia 1

BACKGROUND

Subtotal parathyroidectomy (SPTX) is the treatment of choice for hyperparathyroidism in a patient with multiple endocrine neoplasia type 1 (HPT-MEN-1). There are scarce data on the causes, timing, and appropriate surgical treatment of patients with recurrent HPT-MEN-1. The aim of this study was to investigate the timing, causes, site of recurrence, and surgical treatment of recurrent HPT-MEN-1 in patients who underwent SPTX.

METHODS

The study was a retrospective review of prospectively collected data on patients with HPT-MEN-1 with SPTX at two referral institutions. The data collected included the following: demographics, duration of follow-up, weight of resected parathyroid tissue, type of remnant, time to reoperation, cause/site of recurrence, and surgical treatment. We studied prognostic factors of recurrence.

RESULTS

A total of 69 patients underwent SPTX and were followed for a mean of 75.3 months. After the surgery, 15 patients were left with a single "normal" gland and 54 with a 50- to 70-mg remnant of a partially excised abnormal gland. Nine patients (13%) had a recurrence within a mean of 85 months (12-144 months). Patients with a recurrence had been followed longer (115 vs. 66 months; p = 0.005). Five recurrences occurred in a parathyroid remnant, 3 in a previously "normal" gland; the fifth recurrence was in both a hyperplastic remnant and a fifth gland. Remedial surgery included five subtotal resections and four immediate parathyroid autotransplantations. Two patients had a second recurrence due to a supernumerary gland. Factors related with recurrence are the follow-up time (p < 0.01) and thymectomy (p < 0.003).

CONCLUSIONS

Recurrence of HPTP-MEN-1 usually is located in preserved parathyroid tissue with no preference for a previously normal gland or a remnant. A second recurrence is most likely seen in a supernumerary gland. Recurrence is associated with the follow-up time and thymectomy.

Multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal-dominant inherited tumor syndrome characterized by hyperplasia and/or tumors in the parathyroid glands, the pancreatic islets, the anterior pituitary and adrenal glands, as well as neuroendocrine tumors in the thymus, lungs and stomach, and tumors in nonendocrine tissues. In 1997, the responsible MEN1 gene was identified as a tumor-suppressor gene and its product was named menin. In this review, guidelines for early diagnosis, including MEN1 gene mutation analysis, and treatment, including periodic clinical monitoring, have been formulated, enabling improvement of life expectancy and quality of life. Identification of menin-interacting proteins has provided new insights into the function of menin, notably involving regulation of gene transcription related to proliferation and apoptosis, genome stability and DNA repair, and endocrine/metabolic homeostasis. In the near future, target-directed intervention may prevent or delay the onset of MEN 1-related tumors.

Hyperparathyroidism and multiple endocrine neoplasia

Multiple endocrine neoplasia (MEN) syndromes comprise the group of heritable endocrinopathies, MEN 1, MEN 2A, and MEN 2B. Primary hyperparathyroidism caused by multiglandular involvement is usually the initial manifestation in MEN 1, occurring in more than 90% of patients. In patients with MEN 2A, hyperparathyroidism develops less commonly and is usually milder than in MEN 1. Advances in genetics and molecular biology aid in confirming the diagnosis and screening relatives who are carriers or at risk for the disease. Surgery plays an important role in the management of hyperparathyroidism in both MEN 1 and MEN 2A,although the timing and extent of surgery are areas of controversy.Long-term follow-up reveals a high rate of recurrent hyperparathyroidism in MEN 1 despite surgical intervention.

[Surgery of hyperparathyroidism and of its potential recurrence in the MEN I setting]

Hyperparathyroidism (HPT) in the setting of multiple endocrine neoplasia type 1 (MEN I) is almost constant and occurs often early in the course of the disease. Underlying pathology is almost always multiglandular because of its genetic origin, and therefore, in case of less than subtotal parathyroidectomy, recurrence rate amounts to 20-40%. Operative strategy aims to find and check all parathyroid glands including possible supernumerary one(s) found in 30% of patients and to perform a subtotal parathyroidectomy. Combined transcervical thymectomy is a mandatory part of the procedure. Moreover HPT triggers the secretion of associated gastrinomas and its cure can thus delay the timing of duodenopancreatic surgery. In case of recurrent HPT, preoperative work-up yields to image the parathyroid remnant and possible supernumerary gland(s). Reoperation aims to remove all parathyroid tissue. Cryopreservation can be useful in case of permanent long-lasting symptomatic hypoparathyroidism.

Preoperative parathyroid localization: correlating false-negative technetium 99m sestamibi scans with parathyroid disease

OBJECTIVE/HYPOTHESIS

The recent trend toward minimally invasive directed parathyroid surgery has increased the surgeon's reliance on preoperative parathyroid localization. Technetium Tc 99m sestamibi scanning is generally viewed as the gold standard for preoperative localization, with reported sensitivities of 75% to 100% and specificities of 75% to 90%. However, in each reported series there exists a group of patients in whom preoperative localization is either equivocal or negative.

STUDY DESIGN

We focused on a subset of patients from our parathyroid database with false-negative sestamibi (MIBI) scans, in an attempt to elucidate features that could affect these studies. We identified 20 patients with negative preoperative scans and confirmed parathyroid disease. We compared them with 22 consecutive patients with positive scans, correlating the following variables: patient age, gender, concomitant thyroid disease (Hashimoto's thyroiditis, papillary thyroid carcinoma, thyroid adenoma), preoperative parathyroid hormone values, location and number of enlarged parathyroid glands, parathyroid weight, and the relative proportion of chief cells, clear cells, oxyphil cells, and adipose tissue.

METHODS

Retrospective chart review of clinicopathological and radiological findings.

RESULTS

We found that patients with false-negative scans were more likely to have an enlarged parathyroid containing a high proportion of clear cells (P =.01). A trend was seen (P =.1) correlating increased parathyroid fat content and false-negative scans. Conversely, positive preoperative scans were more likely to be associated with a higher percentage of oxyphil cells (P =.02). Univariate analysis for other variables, as well as logistic regression analysis, did not achieve statistical significance.

CONCLUSIONS

To date, the present study is the largest clinicopathological review of patients with false-negative sestamibi scans. Technetium Tc 99m uptake correlates with parathyroid oxyphil cell content, and false-negative scans can occur with parathyroid glands containing predominantly clear cells.

Long-term results of less than total parathyroidectomy for hyperparathyroidism in multiple endocrine neoplasia type 1

BACKGROUND

Our aim was to assess long-term results after less than total parathyroidectomy for hyperparathyroidism in multiple endocrine neoplasia type 1.

METHODS

Of 1888 patients undergoing operation at our institution for primary hyperparathyroidism between 1972 and 2001, 83 (4.4%) had multiple endocrine neoplasia type 1. Outcome data were available for 79; 66 underwent subtotal parathyroidectomy, 55 (83%) of these with bilateral thymectomy. In 13 patients, only grossly enlarged glands were resected (mean 1.1 per patient) as the syndrome of multiple endocrine neoplasia type 1 was not yet evident or the initial exploration was performed elsewhere.

RESULTS

Follow-up has been 48 +/- 51 months (mean + SD). Intraoperative serum PTH assay decay in 20 patients was suggestive of cure in 18 patients, none of whom required reoperation. Nine patients (11%) required reoperation (3 required reoperation twice) after a mean interval of 77 +/- 53 months. Subtotal parathyroidectomy resulted in a lesser reoperation rate than resection of grossly enlarged glands (7% vs 30%, P =.02). At the time of review, 63 patients (80%) were normocalcemic, 10 (13%) hypocalcemic (2 after unsuccessful delayed autograft), and 7% hypercalcemic (none after reoperation). By Kaplan-Meier analysis, the rate of surgical cure (patients who are nonhypercalcemic) is 60% and 51% at 10 and 15 years, respectively.

CONCLUSION

Subtotal parathyroidectomy reduces the need for reoperation. Selective reoperation leads to long-lasting biochemic cure.

Multiple endocrine neoplasia type I

Multiple endocrine neoplasia type I is a rare autosomal dominant disorder with many endocrine and nonendocrine manifestations. Hyperparathyroidism, islet cell tumors, and pituitary tumors are diagnosed most commonly in these patients. There is controversy regarding treatment of the different manifestations and screening modalities of this disorder because no large series has determined the best therapeutic approach. Our institution advocates early screening with biochemical and radiographic testing in patients with a definite predilection for this disorder. Patients with hyperparathyroidism should undergo early surgical intervention of at least three and a half glands combined with bilateral upper thymectomy through a cervical incision. Although the recurrence rate is high, disease-free survival can be for as long as 30 years. Pituitary tumors are predominantly prolactinomas and growth hormone-releasing tumors. Prolactinomas usually require pharmacologic therapy, whereas growth hormone-releasing tumors are treated surgically. Enteropancreatic tumors should be treated surgically or medically, depending on the hormone secreted. Insulinomas respond well to distal pancreatectomy, with enucleation of the tumor from the head and uncinate process of the pancreas. However, there is controversy regarding the surgical treatment of gastrinomas. Carcinoid tumors should be treated with early surgical intervention. Adrenal lesions are thought to occur in association with pancreatic lesions and commonly have an indolent course. Adrenocortical cancers are uncommon in patients with multiple endocrine neoplasia type I. Skin lesions can be excised when cosmetically unappealing.

Early surgical intervention and strategy in patients with multiple endocrine neoplasia type 1

Patients with multiple endocrine neoplasia type 1 (MEN-1) are an unusual challenge to the endocrine surgeon. Pituitary disease is often treated without surgery, but nearly all patients will require parathyroidectomy for parathyroid hyperplasia. Subtotal parathyroidectomy can be accomplished with a very low rate of permanent hypoparathyroidism and an acceptable rate of recurrent hyperparathyroidism. The treatment of pancreaticoduodenal disease is quite controversial. Even when associated with the Zollinger-Ellison syndrome, early and aggressive surgical treatment should be considered to influence the hormonal syndrome as well as to address the malignant potential of both pancreatic and duodenal tumours. This includes distal pancreatectomy, enucleation of pancreatic head lesions, and duodenotomy with the resection of gastrinomas. Many patients may be completely cured of the manifestations of their disease. As MEN-1 is an uncommon entity, there are very few prospective, randomized data upon which to base surgical judgements.