Zollinger-Ellison syndrome. Clinical presentation in 261 patients

Prospective study of surgery for primary hyperparathyroidism (HPT) in multiple endocrine neoplasia-type 1 and Zollinger-Ellison syndrome: long-term outcome of a more virulent form of HPT

BACKGROUND

Primary hyperparathyroidism (HPT) in multiple endocrine neoplasia type 1 (MEN1) patients with Zollinger-Ellison syndrome (ZES) is caused by parathyroid hyperplasia. Surgery for parathyroid hyperplasia is tricky and difficult. Long-term outcome in ZES/MEN1/HPT is not well known.

METHODS

Eighty-four consecutive patients (49 F/35 M) with ZES/MEN1/HPT underwent initial parathyroidectomy (PTX) and were followed at 1- to 3-year intervals.

RESULTS

Age at PTX was 36 +/- 2 years. Mean follow-up was 17 +/- 1 years. Before PTX, mean Ca = 2.8 mmol/L (normal level (nl <2.5), PTH i = 243 pg/mL (nl <65), and gastrin = 6950 pg/mL (nl < 100). Sixty-one percent had nephrolithiasis. Each patient had parathyroid hyperplasia. Fifty-eight percent of patients had 4 parathyroid glands identified. Nine of 84 (11%) had 4 glands removed with immediate autograft, 40/84 (47%) 3 to 3.5 glands, whereas 35/84 (42%) <3 glands removed. Persistent/recurrent HPT occurred in 42%/48% of patients with <3 glands, 12%/44% with 3 to 3.5 glands, and 0%/55% with 4 glands removed. Hypoparathyroidism occurred in 3%, 10%, and 22%, respectively. The disease-free interval after surgery was significantly longer if >3 glands were removed. After surgery to correct the HPT, each biochemical parameter of ZES was improved and 20% of patients no longer had laboratory evidence of ZES.

CONCLUSIONS

HPT/MEN1/ZES is a severe form of parathyroid hyperplasia with a high rate of nephrolithiasis, persistent and recurrent HPT. Surgery to correct the hypercalcemia significantly ameliorates the ZES. Removal of less than 3.5 glands has an unacceptably high incidence of persistent HPT (42%), whereas 4-gland resection and transplant has a high rate of permanent hypoparathyroidism (22%). More than 3-gland resection has a longer disease-free interval. The surgical procedure of choice for patients with HPT/MEN1/ZES is 3.5-gland parathyroidectomy. Careful long-term follow-up is necessary as a significant proportion will develop recurrent HPT.

Sporadically occurring functional pancreatic endocrine tumors: review of recent literature

PURPOSE OF REVIEW

Pancreatic neuroendocrine tumors are rare neoplasms often associated with a clinical syndrome. Their rarity makes a comprehensive study difficult at any single institution, while their uniqueness makes them desirable for investigation. This review summarizes recent information and advancements concerning pancreatic neuroendocrine tumor diagnosis, imaging characteristics, treatment algorithms, and staging.

RECENT FINDINGS

Insulinomas and gastrinomas comprise the majority of functional pancreatic neuroendocrine tumors. Advances in their identification and diagnostic evaluation, imaging techniques, and treatment algorithms are presented. Furthermore, a new staging classification system has been proposed which may significantly improve the ability to conduct future multi-institutional investigations on pancreatic neuroendocrine tumors.

SUMMARY

Although rare, a thorough understanding of pancreatic neuroendocrine tumors is essential for all physicians due to the wide variety of symptoms with which patients present. Currently, patients are often misdiagnosed for extended periods of time. This review summarizes the recently published literature about diagnosis, imaging, treatment, and staging of pancreatic neuroendocrine tumors.

Pancreatic neuroendocrine tumours

Pancreatic neuroendocrine tumours are rare tumours ( approximately 1/100,00 population/year) of which 60% are non-functioning. Except for insulinoma all types are malignant in >50% of cases. In multiple endocrine neoplasia (MEN)1, pancreatic neuroendocrine tumours occur in 40-80% of patients and are mostly non-functioning tumours or gastrinomas. Insulinomas are benign in approximately 90%, solitary in 95% of sporadic cases whilst multiple in 90% of MEN1 patients. In contrast approximately 50% gastrinomas and the majority of non-functioning pancreatic neuroendocrine tumours are malignant. Pancreatic neuroendocrine tumours occur in 10-15% of patients with Von Hippel-Lindau (VHL) and are frequently multiple (>30%). Surgical excision is a key aspect of treatment for all cases of sporadic gastrinoma and if >2.5 cm in MEN1. Insulinomas are enucleated if solitary and may require pancreatectomy if multiple. Non-functioning tumours should also be resected if sporadic and if >2 cm in MEN1 or if >2-3 cm in VHL. Tumours <1cm require yearly follow-up by CT or MRI from an early age in VHL. The local treatment for liver metastases is now well established and options include liver resection, chemoembolisation and radiofrequency ablation. Systemic therapies have also been better defined and include radionuclide therapy against somatostatin receptors or MIBG and chemotherapy especially for poorly differentiated tumours. A number of novel agents are currently in clinical development.

Surgery for gastrinoma

Surgery has been demonstrated to offer potential for cure in patients who have sporadic ZES and improved tumor-related survival in all patients who have ZES with gastrinomas larger than 2.5 cm. Techniques such as preoperative localization with SRS and intraoperative localization with duodenotomy have improved the effectiveness of surgical intervention for ZES. Future directions for investigation should include better defining the role of preoperative EUS and developing new, more sensitive techniques for preoperative localization. More research also is needed to define the appropriate indications for pancreaticoduodenectomy in ZES and to determine whether proximal vagotomy should be performed at the time of surgical exploration.

Management of sporadic and multiple endocrine neoplasia type 1 gastrinomas

BACKGROUND

Gastrinomas are functional endocrine duodenopancreatic tumours and are responsible for Zollinger-Ellison syndrome (ZES). Clinical presentation, localization techniques and operative management were reviewed.

METHODS

An electronic search of the Medline database was undertaken for articles published in English between January 1987 and May 2007. This timeframe was chosen because of the fundamental changes in operative strategy, antisecretory therapy and localization techniques during this period.

RESULTS AND CONCLUSION

Most gastrinomas are located in the 'gastrinoma triangle', comprising the head of the pancreas, and the first and second parts of the duodenum. Some 20 per cent of gastrinomas occur in association with multiple endocrine neoplasia type 1 (MEN1) and 50-60 per cent of tumours are malignant at the time of diagnosis. Biochemical evidence justifies operation of which duodenotomy is an essential part. Only complete tumour resection allows 5- and 10-year survival rates of 90 per cent. Pylorus-preserving pancreaticoduodenectomy may be the procedure of choice for MEN1-ZES.

Secretin-receptor and secretin-receptor-variant expression in gastrinomas: correlation with clinical and tumoral features and secretin and calcium provocative test results

CONTEXT/OBJECTIVES

The diagnosis of Zollinger-Ellison syndrome requires secretin testing in 60% of patients. Even with secretin, the diagnosis may be difficult because variable responses occur, and 6-30% have negative testing. The basis for variability or negative responses is unclear. It is unknown whether the tumor density of secretin receptors or the presence of a secretin-receptor-variant, which can act as a dominant negative, is important. The aim of this study was to investigate these possibilities.

PATIENTS/METHODS

Secretin-receptor and variant mRNA expression was determined in gastrinomas using real-time PCR from 54 Zollinger-Ellison syndrome patients. Results were correlated with Western blotting, secretin-receptor immunohistochemistry, with gastrin-provocative test results and tumoral/clinical/laboratory features.

RESULTS

Secretin-receptor mRNA was detectible in all gastrinomas but varied 132-fold with a mean of 0.89 +/- 0.12 molecules per beta-actin. Secretin-receptor PCR results correlated closely with Western blotting (r = 0.95; P < 0.0001) and receptor immunohistochemistry (P = 0.0015; r = 0.71). The variant was detected in all gastrinomas, but levels varied 102-fold and were 72-fold lower than the total. Secretin-receptor levels correlated with variant levels, Deltasecretin, but not Deltacalcium and with tumor location, but not growth, extent, or clinical responses. Variant levels did not correlate with the Deltasecretin. Detailed analysis provides no evidence that variant expression modified the secretin-receptor response or accounted for negative tests.

CONCLUSIONS

Secretin-receptor and secretin-receptor-variant expressions occur in all gastrinomas. Because the expression of the total, but not variant, correlated with the secretin results and no evidence for dominant negative activity of the variant was found, our results suggest that the total secretin-receptor density is an important determinant of the secretin test response.

Pancreatic neuroendocrine tumours

Pancreatic neuroendocrine tumours (PET) are rare neoplasms of the pancreas accounting for less than 5% of all primary pancreatic malignancies. Included in this group are insulinomas, gastrinomas, glucagonoma and somatostatinomas. Collectively these neoplasms are classified as functional PETs. Where a PET is not associated with a clinical syndrome due to hormone oversecretion, it is referred to as a non-functioning PET. Non-functioning PETs are pancreatic tumours with endocrine differentiation but lack a clinical syndrome of hormone hypersecretion. The incidence of these tumours varied between 15 and 53%. Presentation is related to the mass effect of the tumour with symptoms often non-specific. Treatment is surgical excision with chemotherapy and hormonal therapy is controversial. For functioning PETs, surgery remains the optimal therapy, however, long-term survival can be expected even in the presence of metastases. With advances in medical management, radiolabelled somatostatin therapy, hepatic arterial chemoembolisation and radiofrequency ablation, symptoms may be controlled to optimize quality of life.

Scintigraphic imaging of body neuroendocrine tumors

Radionuclide imaging is often used in the diagnosis and work-up of a wide range of neoplasms, on the basis of the biologic behavior of the tumor. Neuroendocrine tumors are a subgroup of neoplasms that are generally small and slow growing, and consequently their identification with conventional anatomic imaging can be difficult. Depending on the physiologic properties of the tumor, functional images obtained with radionuclides are often complementary to anatomic images, not only in the localization of the tumor and its metastases, but also in the assessment of prognosis and response to therapy. Familiarity with the choice of the appropriate radiopharmaceutical, proper imaging protocols, and the wide range of imaging patterns will enable the radiologist to guide the clinician in case management.

Chronic hypergastrinemia: causes and consequences

The hormone gastrin plays 2 important roles in gastrointestinal physiology--1 as a major factor in meal-stimulated gastric acid secretion and the other as a trophic hormone for epithelial and enterochromaffin cells. These roles are exaggerated to the point of pathology under conditions of chronic hypergastrinemia as exemplified by the Zollinger-Ellison syndrome and pernicious anemia. More recently, the concern about the potential risk of chronic hypergastrinemia has risen because of the widespread use of proton pump inhibitors for maintenance therapy in reflux esophagitis. For this reason, we present a concise overview of the origin, causes, and potential risks of chronic hypergastrinemia.

[Rare occurrence of fulminant acid burn of the esophagus]

Peptic ulcer due to Zollinger-Ellison syndrome is a rare entity. In this case report a 55-year-old man had a medical history of esophageal reflux, vomiting, and diarrhea for 10 years. Despite continuous medication with a proton pump inhibitor, no complete recovery from symptoms was achieved. A diagnosis of gastrinoma was at first not considered. After discontinuation of the proton pump inhibitor for only a few days, the strong stimulation of the gastrinoma led to fulminant hydrochloric acid burn of the distal esophagus with iatrogenic or spontaneous perforation at the esophagogastral junction. We describe the operative treatment as a two-stage reconstruction with colon interposition and resection of the primary tumor in the duodenum.

Role of CCK/gastrin receptors in gastrointestinal/metabolic diseases and results of human studies using gastrin/CCK receptor agonists/antagonists in these diseases

In this paper, the established and possible roles of CCK1 and CCK2 receptors in gastrointestinal (GI) and metabolic diseases are reviewed and available results from human agonist/antagonist studies are discussed. While there is evidence for the involvement of CCK1R in numerous diseases including pancreatic disorders, motility disorders, tumor growth, regulation of satiety and a number of CCK-deficient states, the role of CCK1R in these conditions is not clearly defined. There are encouraging data from several clinical studies of CCK1R antagonists in some of these conditions, but their role as therapeutic agents remains unclear. The role of CCK2R in physiological (atrophic gastritis, pernicious anemia) and pathological (Zollinger-Ellison syndrome) hypergastrinemic states, its effects on the gastric mucosa (ECL cell hyperplasia, carcinoids, parietal cell mass) and its role in acid-peptic disorders are clearly defined. Furthermore, recent studies point to a possible role for CCK2R in a number of GI malignancies. Current data from human studies of CCK2R antagonists are presented and their potential role in the treatment of these conditions reviewed. Furthermore, the role of CCK2 receptors as targets for medical imaging is discussed.

Serum gastrin in Zollinger-Ellison syndrome: II. Prospective study of gastrin provocative testing in 293 patients from the National Institutes of Health and comparison with 537 cases from the literature. evaluation of diagnostic criteria, proposal of new criteria, and correlations with clinical and tumoral features

In two-thirds of patients with Zollinger-Ellison syndrome (ZES), fasting serum gastrin (FSG) levels overlap with values seen in other conditions. In these patients, gastrin provocative tests are needed to establish the diagnosis of ZES. Whereas numerous gastrin provocative tests have been proposed, only the secretin, calcium, and meal tests are widely used today. Many studies have analyzed gastrin provocative test results in ZES, but they are limited by small patient numbers and methodologic differences. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of gastrin provocative tests in 293 patients with ZES and compare these data with those from 537 ZES and 462 non-ZES patients from the literature. In 97%-99% of gastrinoma patients, an increase in serum gastrin post secretin (Delta secretin) or post calcium (Delta calcium) occurred. In NIH ZES patients with <10-fold increase in FSG, the sensitivity/specificity of the widely used criteria were as follows: Delta secretin > or =200 pg/mL (83%/100%), Delta secretin >50% (86%/93%), Delta calcium > or =395 pg/mL (54%/100%), and Delta calcium >50% (78%/83%). A systematic analysis of the sensitivity and specificity of other possible criteria for a positive secretin or calcium test allowed us to identify a new criterion for secretin testing (Delta > or =120 pg/mL) with the highest sensitivity/specificity (94%/100%) and to confirm the commonly used criterion for calcium tests (Delta > or =395 pg/mL) (62%/100%). This analysis further showed that the secretin test was more sensitive than the calcium test (94% vs. 62%). Our results suggest that secretin stimulation should be used as the first-line provocative test because of its greater sensitivity and simplicity and lack of side effects. In ZES patients with a negative secretin test, 38%-50% have a positive calcium test. Therefore the calcium test should be considered in patients with a strong clinical suspicion of ZES but a negative secretin test. Furthermore, we found that some clinical (diarrhea, duration of medical treatment), laboratory (basal acid output), and tumoral (size, extent) characteristics correlate with the serum gastrin increase post secretin and post calcium. However, using the proposed criteria, the result of these provocative tests (that is, positive or negative) is minimally influenced by these factors, so secretin and calcium provocative tests are reliable in patients with different clinical, laboratory, and tumor characteristics. A systematic analysis of meal testing showed that 54%-77% of ZES patients have a <50% postprandial serum gastrin increase. However, 9%-20% of ZES patients had a >100% increase post meal, causing significant overlap with antral syndromes. Furthermore, we could not confirm the usefulness of meal tests for localization of duodenal gastrinomas. We conclude that the secretin test is a crucial element in the diagnosis of most ZES patients, the calcium test may be useful in selected patients, but the meal test is not helpful in the management of ZES. For secretin testing, the criterion with the highest sensitivity and specificity is an increase of > or =120 pg/mL, which should replace other criteria commonly used today.

Serum gastrin in Zollinger-Ellison syndrome: I. Prospective study of fasting serum gastrin in 309 patients from the National Institutes of Health and comparison with 2229 cases from the literature

The assessment of fasting serum gastrin (FSG) is essential for the diagnosis and management of patients with the Zollinger-Ellison syndrome (ZES). Although many studies have analyzed FSG levels in patients with gastrinoma, limited information has resulted from these studies because of their small size, different methodologies, and lack of correlations of FSG levels with clinical, laboratory, or tumor features in ZES patients. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of 309 patients with ZES and compare our results with those of 2229 ZES patients in 513 small series and case reports in the literature. In the NIH and literature ZES patients, normal FSG values were uncommon (0.3%-3%), as were very high FSG levels >100-fold normal (4.9%-9%). Two-thirds of gastrinoma patients had FSG values <10-fold normal that overlap with gastrin levels seen in more common conditions, like Helicobacter pylori infection or antral G-cell hyperplasia/hyperfunction. In these patients, FSG levels are not diagnostic of ZES, and gastrin provocative tests are needed to establish the diagnosis. Most clinical variables (multiple endocrine neoplasia type 1 status, presence or absence of the most common symptoms, prior medical treatment) are not correlated with FSG levels, while a good correlation of FSG values was found with other clinical features (prior gastric surgery, diarrhea, duration from onset to diagnosis). Increasing basal acid output, but not maximal acid output correlated closely with increasing FSG. Numerous tumoral features correlated with the magnitude of FSG in our study, including tumor location (pancreatic > duodenal), primary size (larger > smaller) and extent (liver metastases > local disease). In conclusion, this detailed analysis of FSG in a large number of patients with ZES allowed us to identify important clinical guidelines that should contribute to improved diagnosis and management of patients with ZES.

Gastrinoma: sporadic and familial disease

The physiologic sequelae of a gastrinoma can be well controlled with medical therapy. The role of surgery has shifted from managing acid hyper-secretion and ulcer complications to preventing metastatic disease and managing symptomatic metastases. With improved methods of imaging for the detection of occult gastrinomas, the prospective evaluation of the role for surgery in altering the natural history of these tumors is now possible.

Surgery increases survival in patients with gastrinoma

OBJECTIVE

To determine whether the routine use of surgical exploration for gastrinoma resection/cure in 160 patients with Zollinger-Ellison syndrome (ZES) altered survival compared with 35 ZES patients who did not undergo surgery.

SUMMARY BACKGROUND DATA

The role of routine surgical exploration for resection/cure in patients with ZES has been controversial since the original description of this disease in 1955. This controversy continues today, not only because medical therapy for acid hypersecretion is so effective, but also in large part because no studies have shown an effect of tumor resection on survival.

METHODS

Long-term follow-up of 160 ZES patients who underwent routine surgery for gastrinoma/resection/cure was compared with 35 patients who had similar disease but did not undergo surgery for a variety of reasons. All patients had preoperative CT, MRI, ultrasound; if unclear, angiography and somatostatin receptor scintigraphy since 1994 to determine resectability. At surgery, all had the same standard ZES operation. All patients were evaluated yearly with imaging studies and disease activity studies.

RESULTS

The 35 nonsurgical patients did not differ from the 160 operated in clinical, laboratory, or tumor imaging results. The 2 groups did not differ in follow-up time since initial evaluation (range, 11.8-12 years). At surgery, 94% had a tumor removed, 51% were cured immediately, and 41% at last follow-up. Significantly more unoperated patients developed liver metastases (29% vs. 5%, P = 0.0002), died of any cause (54 vs. 21%, P = 0.0002), or died a disease-related death (23 vs. 1%, P < 0.00001). Survival plots showed operated patients had a better disease-related survival (P = 0.0012); however, there was no difference in non-disease-related survival. Fifteen-year disease-related survival was 98% for operated and 74% for unoperated (P = 0.0002).

CONCLUSIONS

These results demonstrate that routine surgical exploration increases survival in patients with ZES by increasing disease-related survival and decreasing the development of advanced disease. Routine surgical exploration should be performed in ZES patients.

Endocrine tumors of the pancreas

Neuroendocrine tumors of the pancreas are rare neoplasms of the heterogeneous group of neuroendocrine gastroenteropancreatic tumors that originate from totipotential stem cells or preexisting endocrine cells within the pancreas. Most neuroendocrine tumors of the pancreas are benign or show an indolent course of disease.A subset of them shows a very aggressive behavior, becomes highly malignant, and metastasizes early with life-limiting consequences. An effective disease-management includes the diagnostic approach with hormonal testing and localization and surgical treatment with histologic classification in combination with biotherapy, chemotherapy, or therapy with radionucleotides, de-pending on the individual behavior of the tumor. The primary goal is the improvement of symptoms leading to an acceptable quality of life in the individual patient.

A report of a national mutation testing service for the MEN1 gene: clinical presentations and implications for mutation testing

INTRODUCTION

Mutation testing for the MEN1 gene is a useful method to diagnose and predict individuals who either have or will develop multiple endocrine neoplasia type 1 (MEN 1). Clinical selection criteria to identify patients who should be tested are needed, as mutation analysis is costly and time consuming. This study is a report of an Australian national mutation testing service for the MEN1 gene from referred patients with classical MEN 1 and various MEN 1-like conditions.

RESULTS

All 55 MEN1 mutation positive patients had a family history of hyperparathyroidism, had hyperparathyroidism with one other MEN1 related tumour, or had hyperparathyroidism with multiglandular hyperplasia at a young age. We found 42 separate mutations and six recurring mutations from unrelated families, and evidence for a founder effect in five families with the same mutation.

DISCUSSION

Our results indicate that mutations in genes other than MEN1 may cause familial isolated hyperparathyroidism and familial isolated pituitary tumours.

CONCLUSIONS

We therefore suggest that routine germline MEN1 mutation testing of all cases of "classical" MEN1, familial hyperparathyroidism, and sporadic hyperparathyroidism with one other MEN1 related condition is justified by national testing services. We do not recommend routine sequencing of the promoter region between nucleotides 1234 and 1758 (Genbank accession no. U93237) as we could not detect any sequence variations within this region in any familial or sporadic cases of MEN1 related conditions lacking a MEN1 mutation. We also suggest that testing be considered for patients <30 years old with sporadic hyperparathyroidism and multigland hyperplasia.

Patients with multiple endocrine neoplasia type 1 with gastrinomas have an increased risk of severe esophageal disease including stricture and the premalignant condition, Barrett's esophagus

CONTEXT

Multiple endocrine neoplasia type 1 (MEN1) patients frequently develop Zollinger-Ellison syndrome (MEN1/ZES). Although esophageal reflux symptoms are common in these patients, little is known about long-term occurrence of severe peptic esophageal disease including strictures and Barrett's esophagus (BE).

OBJECTIVE

The objective of the study was to prospectively analyze the frequency of severe peptic esophageal disease in ZES patients with and without MEN1.

SETTING

The study was conducted at a tertiary care research center.

PATIENTS

Two hundred ninety-five patients (80 = MEN1/ZES, 215 = sporadic ZES) participated in a prospective study.

INTERVENTIONS AND OUTCOME MEASURES

Assessment of MEN1, acid hypersecretion, upper gastrointestinal endoscopy/biopsies, and tumor status were measured initially and at each follow-up. Esophageal manometry was performed in 89 patients. Frequency and type of esophageal disease were correlated with clinical/laboratory/tumoral features of ZES/MEN1.

RESULTS

In MEN1/ZES patients, esophageal stricture was 3-fold higher, BE 5-fold higher, and dysplasia 8-fold higher, and one patient died of esophageal adenocarcinoma. Esophageal symptoms were more frequent or severe in MEN1/ZES, but known risk factors for severe esophageal disease and ZES-specific features did not differ between MEN1/ZES and sporadic ZES. In MEN1/ZES, the onset of ZES was 10 yr earlier, and H2-antagonists were used longer and at lower doses. MEN1/ZES patients with esophageal disease differed from those without in that ZES diagnosis was delayed longer, esophageal symptoms were more frequent or severe, hiatal hernias were more frequent, esophagitis or pyloric scarring was more common, basal acid output was higher, and hyperparathyroidism was underdiagnosed.

CONCLUSIONS

This study shows that MEN1/ZES patients have a higher incidence of severe esophageal disease including the premalignant condition BE and identifies factors important for their pathogenesis that need to be incorporated into their long-term treatment.

Consequences of long-term proton pump blockade: insights from studies of patients with gastrinomas

Proton pump inhibitors are being increasingly used and for longer periods of time, especially in patients with gastroesophageal reflux disease. Each of these trends has led to numerous studies and reviews of the potential risk-benefit ratio of the long-term use of proton pump inhibitors. Both long-term effects of hypergastrinaemia due to the profound acid suppression caused by proton pump inhibitors as well as the effects of hypo-/achlorhydria per se have been raised and studied. Potential areas of concern that have been raised in the long-term use of proton pump inhibitors, which could alter this risk-benefit ratio include: gastric carcinoid formation; the development of rebound acid hypersecretion when proton pump inhibitor treatment is stopped; the development of tolerance; increased oxyntic gastritis in H. pylori patients and the possibility of increasing the risk of gastric cancer; the possible stimulation of growth of non-gastric tumours due to hypergastrinaemia; and the possible effect of the hypo/achlorhydria on nutrient absorption, particularly iron and vitamin B12. Because few patients with idiopathic gastro-oesophageal reflux disease/peptic ulcer disease have been treated long-term (i.e., >10 years), there is little known to address the above areas of potential concern. Most patients with gastrinomas with Zollinger-Ellison syndrome have life-long hypergastrinaemia, require continuous proton pump inhibitors treatment and a number of studies report results of >5-10 years of tratment and follow-up. Therefore, an analysis of Zollinger-Ellison syndrome patients can provide important insights into some of the safety concerns raised above. In this paper, results from studies of Zollinger-Ellison syndrome patients and other recent studies dealing with the safety concerns above, are briefly reviewed.

Severe and refractory peptic ulcer disease: the diagnostic dilemma: case report and comprehensive review

The recognition of Helicobacter pylori infection as a cause of peptic ulcer disease, medical regimens to eradicate the organism, and the widespread use of proton pump inhibition to suppress gastric acid secretion have revolutionized the management of peptic ulcer disease. As a result, successful medical management of peptic ulcer disease has largely supplanted the need for gastric surgery by general surgeons. Surgery is reserved for complications of the disease, refractory disease, or rare causes of ulcer disease such as gastrinoma and Zollinger-Ellison syndrome. In this report, we describe a case of intractable peptic ulcer disease that progressed to gastric outlet obstruction despite maximal medical therapy. We review the diagnostic studies utilized to evaluate the potential etiologies of peptic ulcer disease and the difficulty in diagnosing gastrinoma and Zollinger-Ellison in the setting of potent medical acid suppression therapy.

Duodenal neuroendocrine tumors: Classification, functional syndromes, diagnosis and medical treatment

Duodenal neuroendocrine tumors (NETs) comprise 2-3% of all GI endocrine tumors and are increasing in frequency. These include gastrinomas, somatostatinomas, nonfunctional NETs, gangliocytic paragangliomas, and poorly differentiated NE carcinomas. Although, the majority are nonfunctional, these tumors are a frequent cause of Zollinger-Ellison syndrome and can cause other clinical hormonal syndromes (carcinoid, Cushing's, etc.). In this chapter, their epidemiology, clinical aspects, localization, diagnosis and medical treatment are reviewed including the latest advances in each area.

Surgical treatment and prognosis of gastrinoma

Zollinger-Ellison syndrome (ZES) is a clinical syndrome with severe peptic ulcer disease and diarrhea caused by gastric acid hypersecretion secondary to a neuroendocrine tumour that secretes excessive amounts of the hormone gastrin (gastrinoma). Gastrinomas occur in a familial and a sporadic form. Patients with gastrinoma in the familial setting of Multiple Endocrine Neoplasia type 1 (MEN-1) are seldom, if ever, cured of Zollinger-Ellison syndrome by the current non-Whipple operations to remove duodenal and pancreatic gastrinoma. Surgery is currently used in these patients to deal with the malignant nature of pancreatic or duodenal neuroendocrine tumours. Malignant potential is best determined by tumour size. Tumours that are greater than 2 cm in size should be excised. In the sporadic setting, cure occurs in a significant proportion of patients (50%) by surgical resection of gastrinoma. Duodenotomy has improved both the tumour detection rate and the cure rate and should be routinely done. Whipple pancreaticoduodenectomy results in the highest probability of cure in both sporadic and MEN-1 gastrinoma patients as it removes the entire gastrinoma triangle. However, the excellent long-term survival of these patients with lesser operations and the increased operative mortality and long-term morbidity of Whipple make its current role unclear until further studies are done.

Treatment of Zollinger-Ellison Syndrome

In this article, we have reviewed the main therapeutic measures for the treatment of Zollinger-Ellison syndrome (ZES). Review of the literature was based on computer searches (Pub-Med, Index Medicus) and personal experiences. We have evaluated all the measures now available for treating patients with sporadic gastrinomas or gastrinomas associated with Multiple Endocrine Neoplasia Type 1, (MEN 1) including medical therapy such as antisecretory drugs and somatostatin analogs (SST), chemotherapy and chemoembolization, and surgical procedures. In ZES patients, the best therapeutic procedure is surgery which, if radical, can be curative. Medical treatment can be the best palliative therapy and should be used, when possible, in association with surgery, in a multimodal therapeutic approach.

Hereditary hormone excess: genes, molecular pathways, and syndromes

Hereditary origin of a tumor helps toward early discovery of its mutated gene; for example, it supports the compilation of a DNA panel from index cases to identify that gene by finding mutations in it. The gene for a hereditary tumor may contribute also to common tumors. For some syndromes, such as hereditary paraganglioma, several genes can cause a similar syndrome. For other syndromes, such as multiple endocrine neoplasia 2, one gene supports variants of a syndrome. Onset usually begins earlier and in more locations with hereditary than sporadic tumors. Mono- or oligoclonal ("clonal") tumor usually implies a postnatal delay, albeit less delay than for sporadic tumor, to onset and potential for cancer. Hormone excess from a polyclonal tissue shows onset at birth and no benefit from subtotal ablation of the secreting organ. Genes can cause neoplasms through stepwise loss of function, gain of function, or combinations of these. Polyclonal hormonal excess reflects abnormal gene dosage or effect, such as activation or haploinsufficiency. Polyclonal hyperplasia can cause the main endpoint of clinical expression in some syndromes or can be a precursor to clonal progression in others. Gene discovery is usually the first step toward clarifying the molecule and pathway mutated in a syndrome. Most mutated pathways in hormone excess states are only partly understood. The bases for tissue specificity of hormone excess syndromes are usually uncertain. In a few syndromes, tissue selectivity arises from mutation in the open reading frame of a regulatory gene (CASR, TSHR) with selective expression driven by its promoter. Polyclonal excess of a hormone is usually from a defect in the sensor system for an extracellular ligand (e.g., calcium, glucose, TSH). The final connections of any of these polyclonal or clonal pathways to hormone secretion have not been identified. In many cases, monoclonal proliferation causes hormone excess, probably as a secondary consequence of accumulation of cells with coincidental hormone-secretory ability.

[Zollinger-Ellison syndrome]

The preoperative localization of gastrinomas often fails despite all modern imaging methods. Therefore, after biochemical confirmation of the diagnosis and exclusion of diffuse metastases, a meticulous surgical exploration including intraoperative ultrasound (IOUS) and duodenal exploration after duodenotomy should be performed. The experienced surgeon will be able to identify more than 90% of the primary tumors. Depending on the localization, excision of the tumor in the duodenal wall or enucleation from the pancreatic head should be performed. If the tumor is localized in the tail of the pancreas, distal pancreatectomy is the treatment of choice. Complete resection of the tumor is the only curative approach for the patients. For MEN-1 gastrinomas a spleen-preserving distal pancreatectomy with enucleation of tumors of the pancreatic head and duodenotomy with excision of duodenal gastrinomas should be performed. If the source of gastrin secretion can be regionalized to the pancreatic head by a preoperative SASI angiography, a pylorus-preserving partial pancreaticoduodenectomy might be the treatment of choice.

Enteroendocrine tumors other than carcinoid: a review of clinically significant advances

Only relatively recently has there been an increased clinical recognition and characterization of the heterogeneous group of rare gastroenteropancreatic neuroendocrine neoplasms. Most have endocrine function and exhibit varying degrees of malignancy. This review summarizes the derivation of these tumors and the advances in their diagnosis and treatment over the past decade and a half. They are varied in their biological behavior and clinical courses and, depending on their cell type, can produce different hormones causing distinct clinical endocrine syndromes (insulinoma [hypoglycemia], gastrinoma [Zollinger-Ellison syndrome (ZES)], vasoactive intestinal peptideoma [VIPoma], watery diarrhea, hypokalemia-achlorhydria [WDHA], glucagonoma [glucagonoma syndrome], and so forth). In addition to surgery for cure or palliation (by excision and a variety of other cytoreductive techniques), they each are treated with anti-hormonal agents or drugs targeted to each tumor's specific product or its effects. The majority have benefited from the gut hormone-inhibiting action of somatostatin analogs. Because of their usual slow rate of growth it is recommended that, even when they are advanced and incurable, unlike in patients with common and more malignant cancers, patients with neuroendocrine tumors often can be palliated and appear to survive longer when managed with an active approach using sequential multimodality treatment. Advances in these various therapies are reviewed and the beneficial emergence of global self-help patient support groups is noted.

Increased expression of insulin-like growth factor I and/or its receptor in gastrinomas is associated with low curability, increased growth, and development of metastases

PURPOSE

Growth factors, particularly insulin-like growth factor I (IGF-I) and IGF-I receptor (IGF-IR) in some nonendocrine and a few endocrine tumors, are thought important in recurrence, growth, and aggressiveness. Whether this is true of neuroendocrine tumors such as gastrinomas is unclear. The aim of this study was to address this question in gastrinomas.

EXPERIMENTAL DESIGN

IGF-I and IGF-IR expression in gastrinomas from 54 patients with Zollinger-Ellison syndrome were analyzed and correlated with clinical/tumor characteristics. IGF-I and IGF-IR mRNA levels were determined by competitive reverse transcription-PCR. IGF-IR expression, assessed by immunohistochemistry, was done on a subset.

RESULTS

IGF-IR mRNA was found in 100% and IGF-I in 89%. IGF-I mRNA expression varied by >254-fold, IGF-IR by 2,670-fold, and the levels correlated in a given tumor. The IGF-IR level was lower in gastrinomas of patients who were rendered disease free and increased levels correlated with tumor growth, aggressiveness, extent, and with liver metastases. Increased IGF-I levels correlated with increased growth, tumor extent, and aggressiveness. Neither IGF-IR nor IGF-I levels correlated with tumor location, size, or its clinical/functional features. The IGF-IR correlated with disease-free survival. IGF-IRbeta was found in 31 of 32 tumors (97%) by immunohistochemistry.

CONCLUSIONS

These results indicate that IGF-I and IGF-IR are expressed in almost all gastrinomas. Furthermore, assessment of IGF-I/IGF-IR expression in gastrinomas may be clinically useful in identifying those patients with more aggressive tumors who might benefit from more aggressive treatment.

Advances in evaluation and management of gastrinoma in patients with Zollinger-Ellison syndrome

Gastrinomas producing Zollinger-Ellison syndrome are the most frequent symptomatic, malignant pancreatic endocrine tumor syndrome. Recently, a number of important studies have examined their molecular pathogenesis and natural history and provided important guidelines for their treatment. Each of these areas is briefly reviewed in this article.

Localization of gastrinomas by selective intra-arterial calcium injection in patients on proton pump inhibitor or H2 receptor antagonist therapy

Preoperative localization is important for the successful treatment of gastrinomas. The aim of this study was to investigate whether selective intra-arterial calcium injection and hepatic venous sampling was able to localize gastrinomas in four patients who remained on proton pump inhibitor or H2 antagonist therapy. Calcium gluconate was injected directly into the arteries supplying the pancreas and liver after standard selective angiography. Gastrin levels were then measured in samples taken from the right hepatic vein. Calcium gluconate produced a diagnostic rise (at least 2-fold) in serum gastrin and unequivocally localized the tumour to a specific vascular territory in each case. One patient did not undergo surgery. In the remaining three patients, surgery confirmed the position and histology of the tumour. This study shows that in four patients with a confirmed gastrinoma we were able to localize the gastrinoma by selective intra-arterial calcium injection and hepatic venous sampling, whilst the patients remained on proton pump inhibitor or H2 antagonist therapy, thereby reducing their risk of gastrointestinal perforation.

Clinical presentation, diagnosis, and management of gastroesophageal reflux disease

GERD is ubiquitous throughout the adult population in the United States. It commonly adversely affects quality of life and occasionally causes life-threatening complications. The new and emerging medical and endoscopic therapies for GERD and the new management strategies for BE should dramatically reduce the clinical toll of this disease on society.

Guidelines for the management of gastroenteropancreatic neuroendocrine tumours (including bronchopulmonary and thymic neoplasms). Part II-specific NE tumour types

Part II of the guidelines contains a description of epidemiology, histopathology, clinical presentation, diagnostic procedure, treatment, and survival for each type of neuroendocrine tumour. We are not only including gastroenteropancreatic tumours but also bronchopulmonary and thymic neuroendocrine tumours. These guidelines essentially cover basic knowledge in the diagnosis and management of the different forms of neuroendocrine tumour. We have, however, tried to give more updated information about the epidemiology and histopathology, which is essential for the clinical management of these tumours.

Clinical endocrinology and metabolism. Gastrin

The gastric hormone gastrin stimulates gastric acid secretion and epithelial cell proliferation. Multiple active products are generated from the precursor, preprogastrin, including the well-characterized amidated gastrins acting at the cholecystokinin-2 (CCK-2, or gastrin-CCK(B)) receptor, and others that may be growth factors in a range of cancers. Plasma concentrations of the amidated gastrins are elevated as a consequence of gastrin-secreting tumours (gastrinomas) and in conditions in which the normal inhibition of the antral G-cell by acid is depressed, for example chronic atrophic gastritis and prolonged treatment with proton pump inhibitors. There may also be increased gastrin release in Helicobacter pylori infection. Provocative tests for the diagnosis of gastrinoma include the secretin and calcium infusion tests. Hypergastrinaemia is associated with enterochromaffin-like (ECL) cell proliferation; the factors that determine progression to ECL cell dysplasia and gastric ECL cell carcinoid tumours are discussed. Several strategies for inhibiting the effects of gastrin are under evaluation, and their potential application is discussed.

Zollinger-Ellison syndrome revisited: diagnosis, biologic markers, associated inherited disorders, and acid hypersecretion

Despite general awareness of Zollinger-Ellison syndrome (ZES) by most physicians and more than 3000 articles written about it since 1955, the diagnosis of ZES is still delayed for a mean of 5 years. Recent studies show it is being delayed even more with the widespread use of proton pump inhibitors. A number of tumor markers, in addition to assessing serum gastrin, such as chromogranin A, neuron-specific enolase, and subunits of chorionic gonadotropin, have been proposed for use in either the diagnosis of pancreatic endocrine tumors, such as gastrinomas, or for assessment of tumor extent and growth. In this article important recent insights into the diagnosis of ZES as well as the clinical usefulness of assessing tumor markers for diagnosis and determination of disease extent and growth are discussed. Approximately 25% of ZES cases are due to multiple endocrine neoplasia type 1 (MEN1). A number of important studies in this group of patients are also reviewed. Finally, almost every patient with ZES has marked gastric acid hypersecretion, and its current treatment as well as the long-term possible side effects are reviewed briefly.

Resolved and unresolved controversies in the surgical management of patients with Zollinger-Ellison syndrome

OBJECTIVE

Highlight unresolved controversies in the management of Zollinger-Ellison syndrome (ZES).

SUMMARY BACKGROUND DATA

Recent studies have resolved some of the previous controversies including the surgical cure rate in patients with and without Multiple Endocrine Neoplasia-type1 (MEN1), the biological behavior of duodenal and pancreatic gastrinomas, role of imaging studies to localize tumor, and gastrectomy to manage acid output.

METHODS

Review of the literature based on computer searches in Index Medicus, Pubmed and Ovid.

RESULTS

Current controversies as identified in the literature include the role of endoscopic ultrasound (EUS), surgery in ZES patients with MEN1, pancreaticoduodenectomy (Whipple procedure), lymph node primary gastrinoma, parietal cell vagotomy, reoperation and surgery for metastatic tumor, and the use of minimally invasive surgical techniques to localize and remove gastrinoma.

CONCLUSIONS

It is hoped that future studies will focus on these issues to improve the surgical management of ZES patients.

Successful surgical treatment of a primary liver gastrinoma during pregnancy: a case report

Primary neuroendocrine tumors of the liver, particularly gastrinomas, are exceptionally rare. We present a case of a sporadic primary liver gastrinoma in a young woman in whom the definitive diagnosis was reached, and surgical therapy was performed during pregnancy.

Highly penetrant hereditary cancer syndromes

The past two decades have brought many important advances in our understanding of the hereditary susceptibility to cancer. Approximately 5-10% of all cancers are inherited, the majority in an autosomal dominant manner with incomplete penetrance. While this is a small fraction of the overall cancer burden worldwide, the molecular genetic discoveries that have resulted from the study of families with heritable cancer have not only changed the way these families are counselled and managed, but have shed light on molecular regulatory pathways important in sporadic tumour development as well. In this review, we consider 10 of the more highly penetrant cancer syndromes, with emphasis on those predisposing to breast, colon, and/or endocrine neoplasia. We discuss the prevalence, penetrance, and tumour spectrum associated with these syndromes, as well as their underlying genetic defects.

Hereditary pancreatic endocrine tumours

The two main types of hereditary pancreatic neuroendocrine tumours are found in multiple endocrine neoplasia type 1 (MEN-1) and von Hippel-Lindau disease (VHL), but also in the rarer disorders of neurofibromatosis type 1 and tuberous sclerosis. This review considers the major advances that have been made in genetic diagnosis, tumour localization, medical and surgical treatment and palliation with systemic chemotherapy and radionuclides. With the exception of the insulinoma syndrome, all of the various hormone excess syndromes of MEN-1 can be treated medically. The role of surgery however remains controversial ranging from no intervention (except enucleation for insulinoma), intervening for tumours diagnosed only by biochemical criteria, intervening in those tumours only detected radiologically (1-2 cm in diameter) or intervening only if the tumour diameter is > 3 cm in diameter. The extent of surgery is also controversial, although radical lymphadenectomy is generally recommended. Pancreatic tumours associated with VHL are usually non-functioning and tumours of at least 2 cm in diameter should be resected. Practice guidelines recommend that screening in patients with MEN-1 should commence at the age of 5 years for insulinoma and at the age of 20 years for other pancreatic neuroendocrine tumours and variously at 10-20 years of age for pancreatic tumours in patients with VHL. The evidence is increasing that the life span of patients may be significantly improved with surgical intervention, mandating the widespread use of tumour surveillance and multidisciplinary team management.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Does the use of routine duodenotomy (DUODX) affect rate of cure, development of liver metastases, or survival in patients with Zollinger-Ellison syndrome?

OBJECTIVE

To determine whether routine use of duodenotomy (DUODX) alters cure rate, survival, or development of liver metastases in 143 patients (162 operations) with Zollinger-Ellison syndrome (ZES) without MEN1.

SUMMARY BACKGROUND DATA

DUODX has been shown to increase the detection of duodenal gastrinomas, but it is unknown if it alters rate of cure, liver metastases, or survival. Data from our prospective studies of surgery in ZES allow us to address this issue because DUODX was not performed before 1987, whereas it was routinely done after 1987.

METHODS

All patients with sporadic ZES (non-MEN1) undergoing surgery for possible cure without a prior DUODX from November 1980 to June 2003 were included. Patients had preoperative computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound; if unclear, angiography and somatostatin receptor scintigraphy since 1994. At surgery, all had the same standard ZES operation and were assessed immediately postoperatively, at 3 to 6 months, and yearly for cure (fasting gastrin, secretin test. and imaging studies).

RESULTS

A DUODX was performed in 79 patients (94 operations), and no DUODX was performed in 64 patients (68 operations), with 10 patients having both (no DUODX, then a DUODX later). Gastrinoma was found in 98% with DUODX compared with 76% with no DUODX (P < 0.00001). Duodenal gastrinomas were found more frequently with DUODX (62% vs. 18%; P < 0.00001), whereas pancreatic, lymph node, and other primary gastrinomas occurred similarly. Six of the 10 patients with 2 operations had a duodenal tumor found with DUODX during a second operation that was missed in the first operation without DUODX. Both the immediate postoperative cure rate (65% vs. 44%; P = 0.010) and long-term cure rate at last follow-up (8.8 +/- 0.4 years; range, 0.1 to 21.5) (52% vs. 26%; P = 0.0012) were significantly greater with a DUODX than without. In patients without pancreatic tumors or liver metastases at surgery, both the rate of developing liver metastases (6% vs. 9.5%) and the disease-related death rate (0% vs. 2%) were low and not significantly different in patients with or without a DUODX.

CONCLUSIONS

These results demonstrate that routine use of DUODX increases the short-term and long-term cure rate due to the detection of more duodenal gastrinomas. The rate of development of hepatic metastases and/or disease-related mortality in patients without pancreatic tumors is low, and no effect of DUODX on these parameters was seen. Duodenotomy (DUODX) should be routinely performed during all operations for cure of sporadic ZES.

X-chromosome loss of heterozygosity frequently occurs in gastrinomas and is correlated with aggressive tumor growth

BACKGROUND

Recent studies have shown that tumor growth, rather than hormone overproduction, is the leading cause of death among patients with gastrinomas and other malignant gastrointestinal endocrine tumors. No patient/laboratory characteristics accurately predict which tumors will exhibit aggressive growth. Furthermore, little is known regarding the molecular pathogenesis of these tumors. X-chromosome loss of heterozygosity (LOH) occurs in some nonendocrine tumors, and its presence can be associated with aggressive growth/decreased survival. Data on X-chromosome LOH in gastrointestinal endocrine tumors are conflicting. Therefore, the purpose of the current study was to determine whether X-chromosome LOH occurred in gastrinomas and, if so, whether it was correlated with tumor growth, tumor behavior, and/or prognosis.

METHODS

X chromosome allelotyping was performed using 12 microsatellite markers spaced throughout the chromosome using DNA from leukocytes and microdissected gastrinoma specimens from 16 female patients. The presence of X-chromosome LOH was analyzed for correlations with clinical and laboratory tumor characteristics as well as tumor growth characteristics.

RESULTS

Nine gastrinoma specimens (56%) had X-chromosome LOH, ranging from 6% to 23% at the 12 different loci studied. X-chromosome LOH was significantly associated with aggressive postoperative tumor growth, increased primary tumor size, and pancreatic primaries. In 6 tumor specimens, LOH occurred on Xp22.1-22.3 over a 28.4-centimorgan region.

CONCLUSIONS

X-chromosome LOH was common in gastrinoma specimens from female patients, and its presence was found to be a potentially useful molecular/genetic prognostic factor for aggressive growth.

Meningiomas may be a component tumor of multiple endocrine neoplasia type 1

PURPOSE

Recently, an increased incidence of some nonendocrine tumors are reported in patients with multiple endocrine neoplasia type 1 (MEN 1). There are rare reports of meningiomas and other central nervous system tumors in these patients, but it is unknown if they are more frequent or if allelic loss of the MEN1 gene is important in their pathogenesis. The aim of this study was to address these two latter questions.

EXPERIMENTAL DESIGN

Results from a prospective study of 74 MEN 1 patients with suspected/proven pancreatic endocrine tumors (PETs) were analyzed, as well as molecular studies performed on a resected meningioma. All patients had serial brain imaging studies (computed tomography, magnetic resonance imaging, and octreoscanning since 1994) and yearly studies evaluating MEN 1 involvement with a mean follow-up of 7.2 years. Results were compared with 185 patients with sporadic Zollinger-Ellison syndrome.

RESULTS

Six patients (8%) had meningiomas. Meningiomas were single and found late in the MEN 1 course (mean age = 51 years). Magnetic resonance imaging/computed tomography were more sensitive than octreoscanning. Their diagnosis averaged 18 years after the onset of hyperparathyroidism, 10-15 years after pituitary disease or PETs. Meningiomas were 11 times more frequent in patients with PETs with MEN 1 than without MEN 1 (P = 0.017). No clinical, laboratory, or MEN 1 feature distinguished patients with meningiomas. Meningiomas were asymptomatic and 60% showed no growth. A resected meningioma showed loss of heterozygosity at 11q13 and 1p, including at p73 and ARHI/NOEY2 locus, but not at the neurofibromatosis 2 gene locus.

CONCLUSIONS

These results show meningiomas are not an infrequent occurrence in MEN 1, and loss of the function of the MEN1 gene product plays a role in their pathogenesis in these patients.

Multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome: a prospective study of 107 cases and comparison with 1009 cases from the literature

In patients with multiple endocrine neoplasia type 1 (MEN1), the most common functional pancreatic endocrine tumor (PET) syndrome is Zollinger-Ellison syndrome (ZES). ZES has been well studied in its sporadic form (that is, without MEN1); however, there are limited data on patients with MEN1 and ZES (MEN1/ZES), and the long-term natural history is largely unknown. To address this issue we report the results of a prospective long-term National Institutes of Health (NIH) study of 107 MEN1/ZES patients and compare our results with those of 1009 MEN1/ZES patients in 278 case reports and small series in the literature. Patients were clinically, radiologically, and biochemically evaluated yearly for all MEN1 manifestations (mean follow-up, 10 yr; range, 0.1-31 yr). Compared with patients from the literature, the NIH MEN1/ZES patients more frequently had pituitary (60%) and adrenal (45%) disease and carcinoid tumors (30%), but had equal frequency of hyperparathyroidism (94%), thyroid disease (6%), or lipomas (5%). Twenty-five percent of both the NIH and the literature patients lacked a family history of MEN1; ZES was the initial clinical manifestation of MEN1 in 40%. ZES onset preceded the diagnosis of hyperparathyroidism in 45%. However, ZES was rarely (8%) the only initial manifestation of MEN1 if careful testing was done. ZES occurred before age 40 years in 50%-60% of the current patients, in contrast to older studies. The diagnosis of ZES is delayed 3-5 years from its onset and is delayed as long as in sporadic ZES cases. Pituitary disease and carcinoid tumors (gastric > bronchial, thymic) are more frequent than generally reported, whereas a second functional PET is uncommon. In patients with MEN1/ZES without a family history of MEN1, the MEN1 manifestations are not as severe. This study shows that MEN1/ZES patients differ in many aspects from those commonly reported in older studies involving few MEN1/ZES patients. In this study we have identified a number of important clinical and laboratory features of MEN1/ZES that were not previously appreciated, which should contribute to earlier diagnosis and improve both short- and long-term management.