Zollinger-Ellison syndrome. Clinical presentation in 261 patients

Diagnosis of Zollinger-Ellison syndrome: increasingly difficult

In the present paper the increasing difficulty of diagnosis of Zollinger-Ellison syndrome (ZES) due to issues raised in two recent papers is discussed. These issues involve the difficulty and need to withdraw patients suspected of ZES from treatment with Proton Pump Inhibitors (omeprazole, esomeprazole, lansoprazole, rabeprazole, pantoprazole) and the unreliability of many gastrin radioimmunoassays. The clinical context of each of these important issues is reviewed and the conclusions in these articles commented from the perspective of clinical management.

Primary hepatic gastrinoma as an unusual manifestation of zollinger-ellison syndrome

We report a rare case of primary hepatic gastrinoma. A 77-year-old woman exhibited continuous watery diarrhea for 8 months and weight loss. Bacterial cultures of the stools were negative and colonoscopy revealed no abnormalities. Esophagogastroduodenoscopy showed severe reflux esophagitis and multiple duodenal erosions. Computed tomography and magnetic resonance imaging detected two solid masses measuring <2 cm in diameter in the right lobe of the non-cirrhotic liver. Microscopically, the tumor was consistent with neuroendocrine tumor (grade 2) with abundant gastrin-immunoreactive cells. Endoscopic ultrasound detected no other alternative primary source of an endocrine tumor. The serum gastrin levels exceeded 40,000 pg/ml in the absence of H₂ receptor antagonist and proton pump inhibitor administrations. Based on an arterial stimulation and venous sampling test, the patient was diagnosed as primary gastrinoma of the liver. Our findings demonstrated the presence of Zollinger-Ellison syndrome in a patient who was subsequently cured by surgical resection of the liver tumors.

Lymph nodes and survival in pancreatic neuroendocrine tumors

HYPOTHESIS

Lymph node metastases decrease survival in patients with pancreatic neuroendocrine tumors (pNETs).

DESIGN

Prospective database searches.

SETTING

National Institutes of Health (NIH) and Stanford University Hospital (SUH).

PATIENTS

A total of 326 patients underwent surgical exploration for pNETs at the NIH (n = 216) and SUH (n = 110).

MAIN OUTCOME MEASURES

Overall survival, disease-related survival, and time to development of liver metastases.

RESULTS

Forty patients (12.3%) underwent enucleation and 305 (93.6%) underwent resection. Of the patients who underwent resection, 117 (35.9%) had partial pancreatectomy and 30 (9.2%) had a Whipple procedure. Forty-one patients also had liver resections, 21 had wedge resections, and 20 had lobectomies. Mean follow-up was 8.1 years (range, 0.3-28.6 years). The 10-year overall survival for patients with no metastases or lymph node metastases only was similar at 80%. As expected, patients with liver metastases had a significantly decreased 10-year survival of 30% (P < .001). The time to development of liver metastases was significantly reduced for patients with lymph node metastases alone compared with those with none (P < .001). For the NIH cohort with longer follow-up, disease-related survival was significantly different for those patients with no metastases, lymph node metastases alone, and liver metastases (P < .001). Extent of lymph node involvement in this subgroup showed that disease-related survival decreased as a function of the number of lymph nodes involved (P = .004).

CONCLUSIONS

As expected, liver metastases decrease survival of patients with pNETs. Patients with lymph node metastases alone have a shorter time to the development of liver metastases that is dependent on the number of lymph nodes involved. With sufficient long-term follow-up, lymph node metastases decrease disease-related survival. Careful evaluation of number and extent of lymph node involvement is warranted in all surgical procedures for pNETs.

Value of surgery in patients with negative imaging and sporadic Zollinger-Ellison syndrome

OBJECTIVES

To address the value of surgery in patients with sporadic Zollinger-Ellison syndrome (ZES) with negative imaging studies.

BACKGROUND

Medical control of acid hypersecretion in patients with sporadic ZES is highly effective. This has led to these patients frequently not being sent to surgery, especially if preoperative imaging studies are negative, due, in large part, to existence of almost no data on the success of surgery in this group.

METHODS

Fifty-eight prospectively studied patients with sporadic ZES (17% of total studied) had negative imaging studies, and their surgical outcome was compared with 117 patients with positive imaging results.

RESULTS

Thirty-five patients had negative imaging studies in the pre-somatostatin receptor scintigraphy (SRS) era, and 23 patients in the post-SRS era. Patients with negative imaging studies had long disease histories before surgery [mean ± SEM (from onset) = 7.9 ± 1 [range, -0.25 to 35 years]) and 25% were followed for 2 or more years from diagnosis. At surgery, gastrinoma was found in 57 of 58 patients (98%). Tumors were small (mean = 0.8 cm, 60% <1 cm). The most common primary sites were duodenal 64%, pancreatic 17%, and lymph node (10%). Fifty percent had a primary-only, 41% primary + lymph node, and 7% had liver metastases. Thirty-five of 58 patients (60%) were cured immediately postoperatively, and at last follow-up [mean = -9.4 years; range, 0.2-22 years], 27 patients (46%) remained cured. During follow-up, 3 patients died, each had liver metastases at surgery. In comparison to positive imaging patients, those with negative imaging studies had lower preoperative fasting gastrin levels; had a longer delay before surgery; more frequently had a small duodenal tumor; less frequently had a pancreatic tumor, multiple tumors, or developed a new lesion postoperatively; and had a longer survival.

CONCLUSIONS

Sporadic ZES patients with negative imaging studies are not rare even in the post-SRS period. An experienced surgeon can find gastrinoma in almost every patient (98%) and nearly one half (46%) are cured, a rate similar to patients with positive imaging findings. Because liver metastases were found in 7%, which may have been caused by a long delay in surgery and all the disease-related deaths occurred in this group, surgery should be routinely undertaken early in ZES patients despite negative imaging studies.

Primary hepatic gastrinoma presenting as vague gastrointestinal symptoms

A 51-year-old Caucasian female with a 7-year history of intermittent abdominal pain and diarrhoea presented to our service. Before presentation, she had been successfully treated for Helicobacter pylori infection, but later developed new oesophageal ulcerations with exudative lesions that were positive for herpes simplex virus, and candida oesophagitis had developed. Biopsies showed chronic inactive gastritis with gastric intestinal metaplasia. MRI revealed a solid 3.4×3 cm lesion in the caudate lobe of the liver, with a 7-mm pancreatic cyst. The aspirated pancreatic cyst cytology was benign. On exploratory laporatomy, the lesion appeared confined to the caudate lobe, and a resection was performed. The pathology was consistent with a well-differentiated neuroendocrine carcinoma with vascular invasion and involvement of the liver capsule, although resection margins were negative. The patient had complete symptomatic improvement. This case re-affirms the high index of suspicion needed to make the diagnosis of gastrinoma. If caught in time, surgical removal of primary hepatic gastrinoma can be curative.

Pancreatic neuroendocrine tumors: radiographic calcifications correlate with grade and metastasis

BACKGROUND

Studies to identify preoperative prognostic variables for pancreatic neuroendocrine tumor (PNET) have been inconclusive. Specifically, the prevalence and prognostic significance of radiographic calcifications in these tumors remains unclear.

METHODS

From 1998 to 2009, a total of 110 patients with well-differentiated PNET underwent surgical resection at our institution. Synchronous liver metastases present in 31 patients (28%) were addressed surgically with curative intent. Patients with high-grade PNET were excluded. The presence of calcifications in the primary tumor on preoperative computed tomography was recorded and correlated with clinicopathologic variables and overall survival.

RESULTS

Calcifications were present in 16% of patients and were more common in gastrinomas and glucagonomas (50%), but never encountered in insulinomas. Calcified tumors were larger (median size 4.5 vs. 2.3 cm, P=0.04) and more commonly associated with lymph node metastasis (75 vs. 35%, P=0.01), synchronous liver metastasis (62 vs. 21%, P<0.01), and intermediate tumor grade (80 vs. 31%, P<0.01). On multivariate analysis of factors available preoperatively, calcifications (P=0.01) and size (P<0.01) remained independent predictors of lymph node metastasis. Overall survival after resection was significantly worse in the presence of synchronous liver metastasis (5-year, 64 vs. 86%, P=0.04), but not in the presence of radiographic calcifications.

CONCLUSIONS

Calcifications on preoperative computed tomography correlate with intermediate grade and lymph node metastasis in well-differentiated PNET. This information is available preoperatively and supports the routine dissection of regional lymph nodes through formal pancreatectomy rather than enucleation in calcified PNET.

The Zollinger-Ellison syndrome: dangers and consequences of interrupting antisecretory treatment

BACKGROUND & AIMS

Patients with Zollinger-Ellison syndrome (ZES) are treated by proton pump inhibitors (PPIs) to protect them from severe and potentially lethal peptic complications related to massive gastric acid hypersecretion. We report here on the dangerous consequences of interrupting PPI therapy.

METHODS

We describe 2 ZES patients in whom interruption of PPI treatment for diagnostic evaluation generated severe health complications.

RESULTS

Less than 48 hours after stopping PPIs, patient 1 developed multiple strictures of the esophagus caused by massive vomiting of gastric acid, and patient 2 presented with severe abdominal pain with intestinal microperforation from duodenal ulcers. Because of persistent gastrin stimulatory drive and because of the abolition of reflex protective defense mechanisms against gastric acid hypersecretion during PPI treatment, patients with ZES under PPI therapy are exposed to severe peptic complications when facing rebound acid secretion at the interruption of their antisecretory treatment.

CONCLUSIONS

PPI treatment interruption has dangerous consequences, and PPI therapy always should be maintained in patients known or suspected of ZES. Diagnostic evaluations should be performed under PPI protection.

Diagnosis and Treatment of Gastrinomas in Multiple Endocrine Neoplasia Type 1 (MEN-1)

Multiple endocrine neoplasia type 1 (MEN-1) is a rare autosomal-dominant disease. It is associated with a broad range of endocrine tumours, most frequently arising in the parathyroid glands, the pituitary and the pancreas. Most neuroendocrine tumours will be diagnosed in the pancreas as non-functioning neuroendocrine tumours or insulinomas. Forty-two percent of the patients will develop a gastrin-secreting neuroendocrine tumour, a gastrinoma. Gastrinomas in MEN-1 tend to be small, multiple and preferentially located in the duodenum. This paper will focus on the specific characteristics of gastrinomas in the setting of MEN-1 compared to sporadic gastrinomas. The developments in understanding the tumorigenesis of these tumours and the consequences for diagnosis and therapy will be discussed.

A novel missense mutation in the MEN1 gene in a patient with multiple endocrine neoplasia type 1

OBJECTIVE

To describe a novel germline missense mutation in exon 2 of the MEN1 gene identified in a man with multiple endocrine neoplasia type 1 (MEN 1).

METHODS

We describe the patient's clinical, laboratory, and genetic data, and we review the relevant literature.

RESULTS

A 41-year-old man with a history of primary hyperparathyroidism and left lower parathyroidectomy presented with nausea, vomiting, and hematemesis. Laboratory data revealed an elevated gastrin level. Computed tomography of the abdomen demonstrated a 3.5-cm mass in the head of pancreas. A functional study with a somatostatin receptor scan showed increased uptake in the region of the pancreatic mass. The patient's symptoms promptly improved after the Whipple procedure, although he was also noted to have a markedly elevated calcium concentration along with inappropriately elevated parathyroid hormone levels. Sestamibi scan identified a hyperfunctioning right upper parathyroid gland. His calcium level normalized after parathyroidectomy, and results from pituitary hormone studies were all normal. Genetic testing of the MEN1 gene identified a novel mutation: Arg52Gly. The Arg52Gly mutation replaces the normal arginine residue (CGC) with a glycine residue (GGC) at position 52 of the resultant menin protein. This mutation was present in family members from 3 generations.

CONCLUSIONS

We report a novel disease-causing germline missense mutation in exon 2 of the MEN1 gene in a patient with MEN 1. Nonconservative replacement of arginine, a small, neutral amino acid, with glycine, a bulky positively charged amino acid, could potentially have a deleterious effect on the menin protein.

Zollinger-Ellison syndrome: presentation, response to therapy, and outcome

BACKGROUND

Recent series describing the clinical presentation, response to therapy, and long-term outcome of Zollinger-Ellison syndrome are limited.

AIMS

To assess the clinical characteristics and long-term outcome of patients with Zollinger-Ellison syndrome.

METHODS

Over a 20-year period, patients with Zollinger-Ellison syndrome were enrolled in a prospective trial evaluating the efficacy of lansoprazole. Following dose stabilization, patients were followed on a 6-monthly basis with interval history, physical examination, endoscopy with gastric biopsies, gastric acid analysis and laboratory studies.

RESULTS

72 patients (mean age 54±12 years, % male 58%, % Caucasian 69%) were prospectively enrolled. The clinical presentation was stereotypical for Zollinger-Ellison syndrome. Symptoms had been reported for a median of 9 years prior to diagnosis. Cross-sectional abdominal imaging was often negative for demonstrable tumour. All patients had gastric acid hypersecretion controlled with variable doses of lansoprazole (median dose 60 mg/day, range 15-480 mg/day). The median survival from the time of diagnosis was 6.6 years; only two of 19 deaths were due to metastatic gastrinoma.

CONCLUSIONS

The clinical presentation of Zollinger-Ellison syndrome was similar to prior reports. Acid hypersecretion was controlled in all patients with variable doses of lansoprazole. Long-term survival was principally related to underlying co-morbidity.

Pancreatic endocrine tumors with major vascular abutment, involvement, or encasement and indication for resection

BACKGROUND

Surgery for pancreatic endocrine tumors (PETs) with blood vessel involvement is controversial.

HYPOTHESIS

Resection of PETs with major blood vessel involvement can be beneficial.

DESIGN

The combined databases of the National Institutes of Health and Stanford University hospitals were queried.

MAIN OUTCOME MEASURES

Operation, pathologic condition, complications, and disease-free and overall survival.

RESULTS

Of 273 patients with PETs, 46 (17%) had preoperative computed tomography evidence of major vascular involvement. The mean size for the primary PET was 5.0 cm. The involved major vessel was as follows: portal vein (n = 20), superior mesenteric vein or superior mesenteric artery (n = 16), inferior vena cava (n = 4), splenic vein (n = 4), and heart (n = 2). Forty-two of 46 patients had a PET removed: 12 (27%) primary only, 30 (68%) with lymph nodes, and 18 (41%) with liver metastases. PETs were removed by either enucleation (n = 7) or resection (n = 35). Resections included distal or subtotal pancreatectomy in 23, Whipple in 10, and total in 2. Eighteen patients had concomitant liver resection: 10 wedge resection and 8 anatomic resections. Nine patients had vascular reconstruction: each had reconstruction of the superior mesenteric vein and portal vein, and 1 had concomitant reconstruction of the superior mesenteric artery. There were no deaths, but 12 patients had complications. Eighteen patients (41%) were immediately disease free, and 5 recurred with follow-up, leaving 13 (30%) disease-free long term. The 10-year overall survival was 60%. Functional tumors were associated with a better overall survival (P < .001), and liver metastases decreased overall survival (P < .001).

CONCLUSION

These findings suggest that surgical resection of PETs with vascular abutment/invasion and nodal or distant metastases is indicated.

Presentation, response to lansoprazole therapy, and outcome of Zollinger-Ellison syndrome-like gastric acid hypersecretors

OBJECTIVE

To evaluate the clinical characteristics, response to treatment and outcome of Zollinger?Ellison syndrome (ZES)-like gastric acid hypersecretors.

METHODS

Over a 20-year period, patients with gastric acid hypersecretion in the absence of ZES were enrolled in an open label prospective trial evaluating the efficacy of lansoprazole. Following baseline evaluations, patients were treated with escalating doses of lansoprazole based on the results of gastric acid analysis. Following stabilization, patients were followed on a 6 monthly basis with interval history, physical examination, endoscopy with gastric biopsies, gastric acid analysis, and laboratory studies.

RESULTS

The study group represented 21 patients (median age 47 years, 86% male, 91% Caucasian). Historically, complicated ulcer disease was frequent and symptoms had been present for a median of 10 years before study entry. All patients responded to lansoprazole (median dose 90 mg/day) with excellent control of gastric acid hypersecretion. Mucosal relapse was infrequent and no major complications developed while on therapy.

CONCLUSIONS

ZES-like gastric acid hypersecretion presents similarly to the classic syndrome. Lansoprazole titrated to gastric acid output is effective in healing mucosal disease and preventing relapse.

New and emerging syndromes due to neuroendocrine tumors

Neuroendocrine tumors (NETs) are rare, slow-growing neoplasms characterized by their ability to store and secrete different peptides and neuroamines. Some of these substances cause specific clinical syndromes whereas others are not associated with specific syndromes or symptom complexes. NETs usually have episodic expression that makes diagnosis difficult, erroneous, and often late. For these reasons a high index of suspicion is needed, and it is important to understand the pathophysiology of each tumor to decide which biochemical markers are more useful and when they should be used.

Symptoms and diagnosis of neuroendocrine tumors of the digestive system

Neuroendocrine tumors of the digestive system can cause very diverse clinical symptoms. Due to the secretion of biogenic amines, peptides and hormones secreted by the tumor cells, various paraneoplastic syndromes can evolve, on the other hand, the growth and spreading of hormonally inactive tumors can result in different local symptoms. Patients can be symptom-free for a long time or aspecific, often periodical symptoms can prevent recognition or lead to misdiagnosis for years. The symptomatology of hormonally active tumors, derived mainly from the pancreas is very characteristic. Carcinoid syndrome can be seen in 10-18% of patients with neuroendocrine tumors. In this review, the critical appreciation of laboratory and imaging modalities is discussed. Among the major new developments in this field, the introduction of serum chromogranin A assay and new small bowel examination methods should be mentioned. Capsule endoscopy and balloon enteroscopy can provide possibility of much more earlier diagnosis, as previously. The worldwide spreading of endoscopic ultrasound and fine needle biopsy allows the detection and clear localization of pancreatic neuroendocrine tumors. Orv. Hetil., 2011, 152, 371–378.

Pancreatic endocrine tumors

Pancreatic endocrine tumors have been steadily growing in incidence and prevalence during the last two decades, showing an incidence of 4-5/1,000,000 population. They represent a heterogeneous group with very varying tumor biology and prognosis. About half of the patients present clinical symptoms and syndromes related to substances released from the tumors (Zollinger-Ellison syndrome, insulinoma, glucagonoma, etc) and the other half are so-called nonfunctioning tumors mainly presenting with symptoms such as obstruction, jaundice, bleeding, and abdominal mass. Ten percent to 15% of the pancreatic endocrine tumors are part of an inherited syndrome such as multiple endocrine neoplasia type 1 (MEN-1), von Hippel-Lindau (VHL), neurofibromatosis, or tuberousclerosis. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, and glucagon. Moreover, the biochemical diagnosis includes measurement of chromogranins A and B or specific hormones such as gastrin, insulin, glucagon, and vasoactive intestinal polypeptide (VIP) in the circulation. In addition to standard localization procedures, radiology (computed tomography [CT] scan, magnetic resonance imaging [MRI], ultrasound [US]), somatostatin receptor scintigraphy, and most recently positron emission tomography with specific isotopes such as (11)C-5 hydroxytryptamin ((11)C-5-HTP), fluorodopa and (68)Ga-1,4,7,10-tetra-azacyclododecane-N,N',N″,N‴-tetra-acetic acid (DOTA)-octreotate are performed. Surgery is still one of the cornerstones in the management of pancreatic endocrine tumors, but curative surgery is rarely obtained in most cases because of metastatic disease. Debulking and other cytoreductive procedures might facilitate systemic treatment. Cytotoxic drugs, biological agents, such as somatostatin analogs, alpha interferons, mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors are routinely used. Tumor-targeted radioactive treatment is available in many centres in Europe and is effective in patients with tumors that express high content of somatostatin receptors type 2 and 5. In the future, treatment will be based on tumor biology and molecular genetics with the aim of so-called personalized medicine.

Mechanism of acid hypersecretion post curative gastrinoma resection

BACKGROUND

Some patients with Zollinger-Ellison syndrome post curative gastrinoma resection continue to show gastric acid hypersecretion; however, the mechanism is unknown.

AIM

The aim of this study was to prospectively study acid secretion following curative gastrinoma resection and analyze factors contributing in patients with Zollinger-Ellison syndrome.

METHODS

Fifty patients cured post gastrinoma resection were studied with serial assessments of acid secretory status, cure status and ECL-cell status/activity (with serial biopsies, CgA, urinary N-MIAA). Correlative analysis was performed to determine predictive factors.

RESULTS

Hypersecretion occurred in 31 patients (62%) and 14 had extreme-hypersecretion. There was an initial decline (3-6 months) in BAO/MAO, which then remained stable for eight years. Preoperative BAO correlated with the postoperative secretion, but not other clinical, tumoral, laboratory variables, the degree of postoperative acid suppression or type of antisecretory drug needed. Hypersecretors had greater postoperative ECL changes (P=0.005), serum CGA (P=0.009) and 24-h urinary N-MIAA (P=0.0038).

CONCLUSIONS

Post curative resection, gastric hypersecretion persists long term (mean 8 years) in 62% of patients and in 28% it is extreme, despite normogastrinemia. No preoperative variable except BAO correlates with postresection hypersecretion. The persistent increased ECL-cell extent post curative resection suggests prolonged hypergastrinemia can lead to changes in ECL-cells that are either irreversible in humans or sustained by unknown mechanisms not involving fasting hypergastrinemia and which can result in hypersecretion, in a proportion of which it can be extreme. Whether similar findings may occur in patients with idiopathic GERD treated for prolonged periods (>10 years) with PPIs, at present, is unknown.

Neuroendocrine tumors of the small bowels are on the rise: Early aspects and management

Neuroendocrine tumors of the small bowel are on the rise. In the US they have increased by 300%-500% in the last 35 years. At the same time their prognosis is much improved. Today, most neuroendocrine tumors (NETs) of the duodenum are detected "incidentally" and therefore recognized at an early stage. Duodenal NETs which are well differentiated, not larger than 10 mm and limited to the mucosa/submucosa can be endoscopically resected. The management of duodenal NETs ranging between 10 and 20 mm needs an interdisciplinary discussion. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. Surgery is recommended for well-differentiated duodenal NET tumors greater than 20 mm, for localized sporadic gastrinomas (of any size) and for localized poorly differentiated NE cancers. Surgery is recommended for any ileal NET. Advanced ileal NETs with a carcinoid syndrome are treated with long-acting somatostatin analogs. This treatment significantly improves (progression-free) survival in patients with metastatic NETs of the ileum. For optimal NET management, tumor biology, type, localization and stage of the neoplasm, as well as the patient's individual circumstances have to be taken into account.

NANETS treatment guidelines: well-differentiated neuroendocrine tumors of the stomach and pancreas

Well-differentiated neuroendocrine tumors (NETs) of the stomach and pancreas represent 2 major subtypes of gastrointestinal NETs. Historically, there has been little consensus on the classification and management of patients with these tumor subtypes. We provide an overview of well-differentiated NETs of the stomach and pancreas and describe consensus guidelines for the treatment of patients with these malignancies.

Multiple endocrine neoplasia type 1 simultaneous with various types of enteropancreatic endocrine tumors: one case report: lessons learned

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disorder characterized by the development of parathyroid hyperplasia, pancreatic endocrine tumors, pituitary adenomas, and adrenal adenomas. We reported 1 case of MEN 1 simultaneous with gastrinoma and insulinoma; meanwhile, insulinomas were ectopic and recurrent. The genetic screening showed the mutation of 427del AT of the MEN 1 gene. Surgical removal is considered the treatment of choice, with limited adverse effects and relatively low morbidity and mortality. She was treated by means of several surgical strategies, resulting in improvement of the frequency and severity of the hypoglycemic episodes and a better quality of life.

[A young man with chronic diarrhea and epigastric pain]

CASE REPORT

A 26-year-old man was admitted to hospital with a 6-month history of diarrhea and abdominal pain. Before admission, upper and lower gastrointestinal endoscopy had shown a mild erosive duodenitis and the patient was started on a proton pump inhibitor. Physical examination and laboratory tests on admission were not constructive. In addition, repeated gastrointestinal endoscopy, cross-sectional imaging and neuroendocrine markers did not point to a specific etiology. Therefore, as a provocation test, the proton pump inhibitor therapy was discontinued. Discontinuation resulted in a progression of the patient's symptoms and an endoscopic detection of duodenal ulcers. Except for the normal serum gastrin levels, this constellation was suggestive of a gastrinoma, so that further investigations were initiated. Subsequently, the diagnosis could be confirmed and the gastrinoma located. After successful pancreaticoduodenectomy, the patient was symptom-free.

CONCLUSION

As part of a systematic investigation on chronic diarrhea, the work-up for neuroendocrine causes can play an important role. In this context, it should be kept in mind that some gastrinoma patients present without an elevation of serum gastrin levels. Regardless of a negative gastrin test, a typical symptom constellation should therefore prompt further investigations.

Solid tumors of the body and tail of the pancreas

Solid lesions of the body and tail of the pancreas challenge all the diagnostic and technical skills of the modern gastrointestinal surgeon. The information available from modern computed tomography (CT), magnetic resonance (MR), and endoscopic ultrasound (EUS) imaging provide diagnostic and anatomic data that give the surgeon precise information with which to plan an operation and to discuss with the patient during the preoperative visit. A preoperative evaluation includes a thorough history and a pancreas protocol CT scan, supplemented by MR imaging and EUS when needed, to differentiate between the various potential diagnoses. These same modalities can be essential in proper staging in the case of malignant lesions, thus aiding in management decisions. Most lesions ultimately require operative resection, barring metastatic disease, with the notable exception of autoimmune pancreatitis.

An uncommon cause of abdominal pain and diarrhea-gastrinoma in an adolescent

Gastrinoma is a hormone-secreting tumor associated with the Zollinger-Ellison syndrome. It is quite rare among children, and it is also uncommon in locations other than the pancreas and the duodenum in the pediatric group. Here, we describe an adolescent male, presenting with recurrent secretory diarrhea and abdominal cramping pain, who had a solitary gastrinoma in the lesser sac, close to the stomach. The prognosis was good after complete resection.

Surgical management of Zollinger-Ellison syndrome; state of the art

Much has been learned about the diagnosis and treatment of Zollinger-Ellison Syndrome (ZES), and certain questions require further investigation. Delay in diagnosis of ZES is still a significant problem, and clinical suspicion should be elevated. The single best imaging modality for localization and staging of ZES is somatostatin receptor scintigraphy. Goals of surgical treatment for ZES differ between sporadic and MEN-1-related cases. All sporadic cases of ZES should be surgically explored (including duodenotomy) even with negative imaging results, because of the high likelihood of finding and removing a tumor for potential cure. Surgery for MEN-1-related cases should be focused on prevention of metastatic disease, with surgery being recommended when pancreatic tumors are greater than 2 cm. The role of Whipple procedure, especially for MEN-1 cases, should be explored further. Laparoscopic and endoscopic treatments are more experimental, but may have a role.

Gastric acid hypersecretory states: recent insights and advances

Gastric acid hypersecretory states are characterized by basal hypersecretion of gastric acid and historically include disorders associated with hypergastrinemia, hyperhistaminemia, and those of unknown etiology. Although gastric acid secretion is infrequently measured, it is important to recognize the role of gastric hypersecretion in the symptoms of these disorders because they share several features of pathogenesis and treatment. In this article, recent important articles reporting insights into their diagnosis, pathogenesis, and treatment are reviewed. Particular attention is paid to Zollinger-Ellison syndrome, because it has the most extreme acid hypersecretion of this group of disorders and because numerous recent articles deal with various aspects of the diagnosis, molecular pathogenesis, and treatment of the gastrinoma itself or the acid hypersecretion. Two new hypersecretory disorders are reviewed: rebound acid hypersecretion after the use of proton pump inhibitors and acid hypersecretion with cysteamine treatment in children with cystinosis.

Five-Year Long-Term Followup of a Primary Lymph node Gastrinoma: Is a Pancreaticoduodenectomy Justified?

Background. Gastrinoma-positive lymph nodes and failed localization of the primary tumor during surgical exploration are described. Specialists suppose that these lymph nodes are metastases rather than a primary gastrinoma. Methods. Case report with a five-year long-term followup. A 60-year-old patient with an confirmed gastrinoma was treated in our department. All preoperative evaluations including somatostatin-receptor-scintigraphy and F-Dopa PET failed to localize the gastrinoma. Explorative laparotomy revealed a gastrinoma in two peripancreatic lymph nodes. Despite extensive intraoperative exploration, no primary gastrinoma could be detected in typical localization. Results. Over a period of 5 years, the patient's gastrin level stayed in the normal range and the patient seems to be completely cured. Conclusion. A prophylactic partial pancreatoduodenectomy is not indicated to avoid recurrence, since complete biochemical cure by local resection of the lymph node gastrinoma is possible.

PPI-delayed diagnosis of gastrinoma: oncologic victim of pharmacologic success

Functional neuroendocrine tumors are often low-grade malignant neoplasms that can be cured by surgery if detected early, and such detection may in turn be accelerated by the recognition of neuropeptide hypersecretion syndromes. Uniquely, however, relief of peptic symptoms induced by hypergastrinemia is now available from acid-suppressive drugs such as proton-pump inhibitors (PPIs). Here we describe a clinical case in which time to diagnosis from the onset of peptic symptoms was delayed more than 10 years, in part reflecting symptom masking by continuous prescription of the PPI omeprazole. We propose diagnostic criteria for this under-recognized new clinical syndrome, and recommend that physicians routinely measure serum gastrin levels in persistent cases of PPI-dependent dyspepsia unassociated with H. pylori.

Refractory peptic ulcer disease

Refractory PUD is a diagnostic and therapeutic challenge. Optimal management of severe or refractory PUD requires a multidisciplinary team approach, using primary care providers, gastroenterologists, and general surgeons. Medical management has become the cornerstone of therapy. Identification and eradication of H pylori infection combined with acid reduction regimens can heal ulceration and also prevent recurrence. Severe, intractable or recurrent PUD and associated complications mandates a careful and methodical evaluation and management strategy to determine the potential etiologies and necessary treatment (medical or surgical) required.

Review article: Strategies to determine whether hypergastrinaemia is due to Zollinger-Ellison syndrome rather than a more common benign cause

BACKGROUND

As there is considerable overlap between the fasting serum gastrin concentrations found in Zollinger-Ellison syndrome and various common conditions such as Helicobacter pylori infection and acid suppressing medication use, establishing the cause of hypergastrinaemia in individual cases can sometimes be difficult.

AIM

To review the causes of hypergastrinaemia and the role of additional non-invasive investigations in hypergastrinaemic patients.

METHODS

Review of articles following a Pubmed search.

RESULTS

As gastrinomas may cause serious complications and be potentially life threatening, investigation of hypergastrinaemic patients should particularly focus on confirming or refuting the diagnosis of Zollinger-Ellison syndrome. Establishing the cause of hypergastrinaemia may be difficult when there is only a mild-to-moderate elevation of fasting serum gastrin concentration and concurrent treatment with proton pump inhibitor drugs and the presence of H. pylori infection can both confuse the clinical picture. A variety of provocative tests are therefore useful for establishing whether a hypergastrinaemic patient has a gastrinoma and current evidence suggests that the secretin test should be used first line.

CONCLUSIONS

We suggest an algorithm for the investigation of patients found to have an elevated fasting serum gastrin concentration and address the roles of gastrin stimulation tests in current clinical practice.

Neuroendocrine tumors of the pancreas

This literature review briefly summarizes the epidemiology, pathophysiology, clinical management, and outcomes of patients with pancreatic neuroendocrine tumors (PNETs) and highlights recent advances in PNET research. PNETs are rare neoplasms, compared with carcinomas arising from pancreatic exocrine tissue. They, like other neuroendocrine tumor types, display variable malignant potential, hormone-related syndromes (functionality), localization, and genetic background. Although tumor origin and molecular pathogenesis remain poorly understood, recently established grading and staging systems facilitate patient risk stratification, and thereby directly impact clinical decision making. Although the optimal clinical management of PNETs involves a multidisciplinary approach, surgery remains the only curative treatment for early-stage disease. Surgery may also have a role in patients with advanced-stage disease, including those with hepatic metastases. Alternative therapeutic approaches applied to PNETs, including chemotherapy, radiofrequency ablation, transarterial chemoembolization, biotherapy, polypeptide radionuclide receptor therapy, antiangiogenic therapy, and selective internal radiotherapy, have failed to demonstrate a long-term survival benefit. Surgery remains the primary therapeutic option for patients with PNETs. Research on PNETs is desperately needed to improve the therapeutic options for patients with this disease.

Treatment strategies for Zollinger-Ellison syndrome

BACKGROUND

Zollinger-Ellison syndrome (ZES) is a rare disorder caused by tumor secretion of the hormone gastrin, which results in gastric acid hypersecretion and secondarily complicated peptic ulcer and diarrhea. Until the development of H(2)-receptor antagonists and later proton pump inhibitors (PPIs), the disease was virulent, often associated with ulcer-related mortality, and the mainstay of treatment was total gastrectomy.

OBJECTIVE

To evaluate current approaches to diagnosis and therapy, focusing on the role of PPIs.

METHODS

An extensive literature search through PubMed using the search term 'Zollinger-Ellison syndrome' from 1964 to the present was performed. Primary articles were identified, and pertinent articles obtained from the reference lists were also examined.

RESULTS/CONCLUSIONS

The clinical manifestations of ZES are well described, but overlaps with other more common disorders delay diagnosis. The use of abdominal imaging with somatostatin receptor scintigraphy and endoscopic ultrasound has improved tumor staging. PPI therapy is remarkably effective in controlling gastric acid hypersecretion, thereby reducing morbidity and potential mortality of this syndrome. The dose of drug necessary to control symptoms is highly variable but, even when used in high doses for prolonged periods of time, the disease remained controlled with very few drug-related side effects.

Gastrointestinal neuroendocrine tumors: pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) have long fascinated clinicians and investigators despite their relative rarity. Their clinical presentation varies depending on whether the tumor is functional or not, and also according to the specific hormonal syndrome produced. Tumors may be sporadic or inherited, but little is known about their molecular pathology, especially the sporadic forms. Chromogranin A appears to be the most useful serum marker for diagnosis, staging, and monitoring. Initially, therapy should be directed at the hormonal syndrome because this has the major initial impact on the patient's health. Most PETs are relatively indolent but ultimately malignant, except for insulinomas, which predominantly are benign. Surgery is the only modality that offers the possibility of cure, although it generally is noncurative in patients with Zollinger-Ellison syndrome or nonfunctional PETs with multiple endocrine neoplasia-type 1. Preoperative staging of disease extent is necessary to determine the likelihood of complete resection although debulking surgery often is believed to be useful in patients with unresectable tumors. Once metastatic, biotherapy is usually the first modality used because it generally is well tolerated. Systemic or regional therapies generally are reserved until symptoms occur or tumor growth is rapid. Recently, a number of newer agents, as well as receptor-directed radiotherapy, are being evaluated for patients with advanced disease. This review addresses a number of recent advances regarding the molecular pathology, diagnosis, localization, and management of PETs including discussion of peptide-receptor radionuclide therapy and other novel antitumor approaches. We conclude with a discussion of future directions and unsettled problems in the field.

Is laparoscopic resection adequate in patients with neuroendocrine pancreatic tumors?

Since the first reports with laparoscopic resection of islet cell tumors in 1996, the experience worldwide is still limited, with only short-term outcomes available. Some have suggested that a malignant tumor is a contraindication to laparoscopic resection. Aim The aim of this study was to evaluate the feasibility, safety, and long-term outcome of the laparoscopic approach in patients with functioning, nonfunctioning, or overt malignant pancreatic neuroendocrine tumor (PNT). To our knowledge this is the largest single-institution series on this subject to date. Patients and methods A total of 49 consecutive patients (43 women, 6 men; mean age 58 years, range 22-83 years) underwent laparoscopic pancreatic surgery (LPS) from April 1998 to June 2007. Preoperative localization was done by computed tomography, magnetic resonance imaging, endoscopic ultrasonography, and Octreoscan imaging. Other than 9 PNTs localized in the head of the pancreas, all tumors were located in the left pancreas. Malignancy was diagnosed based on the presence of lymph nodes or liver metastasis. There were 33 patients with functioning tumors: 4 with gastrinomas (mean size 1.2 cm), 1 with a glucagonoma (4 cm), 3 with vipomas (3.2 cm), 2 with carcinoids (5.2 cm), 20 with sporadic insulinomas (1.4 cm), 2 with insulinoma/multiple endocrine neoplasia type 1 (MEN-1) (4.4 cm), and 1 with a malignant insulinoma (13 cm). Sixteen patients had a nonfunctioning tumor (mean size 5 cm). The following techniques were performed: laparoscopic spleen-preserving distal pancreatectomy (Lap SPDP), laparoscopic distal pancreatectomy with splenectomy (Lap SxDP) and laparoscopic enucleation (Lap En)/laparoscopic excision (Lap E). Lymph node dissection was performed when malignancy was suspected (Strasberg s technique). Evaluation criteria included operative and postoperative factors, pathologic data including R0 or R1 resection (the pancreatic transection margin and all transection margins on the specimen were inked). Long-term outcomes were analyzed by tumor recurrence and patient survival. Results Four cases (8.2%) were converted to open surgery. Overall, Lap SPDP, Lap SxDP, and Lap En/Lap E were performed in 15 (33.3%), 8 (17.8%), and 22 (48.9%) patients, respectively. The operative time and blood loss was significantly lower in the Lap En group compared with the other laparoscopic techniques. The group of patients with malignant tumors undergoing Lap SxDP had a longer operating time and greater blood loss compared with the other distal pancreatectomy (Lap DP) techniques. Overall, the postoperative complications were significantly higher in the Lap En group (42.8%) than in the Lap DP (Lap SPDP+Lap SxDP) group (22%). These complications were mainly pancreatic fistula: 8.7% after Lap DP and 38% after Lap En. The overall morbidity was significantly higher after Lap SPDP (26.7%) than after Lap SxDP (12.5%) owing to the occurrence of splenic complications in the Lap SPDP group without splenic vessel preservation two of seven (28.5%). The means and ranges of hospital stay after Lap SPDP, Lap SxDP, and Lap En/Lap E were 5.9 (5-14), 7.5 (5-12), and 5.5 (5-7) days, respectively (NS). Pathology examination of the specimen showed R0 resection in all patients with malignant PNT. The mean time to resumption of previous activities for patients undergoing Lap DP or Lap En was 3 weeks. There were no postoperative (30 days) or hospital deaths. Conclusions This series demonstrates that LPS is feasible and safe in benign-appearing and malignant neuroendocrine pancreatic tumors (NEPTs). The benefits of minimally invasive surgery were manifest in the short hospital stay and acceptable pancreas-related complications in high-risk patients. LPS can achieve negative tangential margins in a high percentage of patients with malignant tumors. Although surgical cure is rare in malignant NEPTs, significant long-term palliation can be achieved in a large proportion of patients with an aggressive surgical approach.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Giant gastrinoma in a child: case report and review

Gastrinomas are rare neuroendocrine tumours. A 9-year-old boy who initially presented with recurrent upper abdominal pain and was managed as hyperacidity syndrome was later diagnosed to have a primary, retroperitoneal, extra pancreatic gastrinoma after an asymptomatic period of 6 years is presented. At the second presentation, the contrast-enhanced CT revealed an epigastric mass and serum gastrin was grossly elevated. A complete excision of the mass was done; histopathological evaluation showed a well-differentiated neuroendocrine tumour. At a year follow up, the child is asymptomatic and the review imaging and serum gastrin levels are normal.

Primary lymph node gastrinoma or occult duodenal microgastrinoma with lymph node metastases in a MEN1 patient: the need for a systematic search for the primary tumor

Gastrinoma tissue has been found frequently in lymph nodes located near the duodenum without a known primary tumor. Therefore, it has been suggested that a primary lymph node gastrinoma exists. We report on a 38-year-old woman suffering from multiple endocrine neoplasia type 1 (MEN1) confirmed by menin gene mutation analysis. MEN1 disease started with primary hyperparathyroidism followed by Cushing disease, the detection of tumors of the pituitary, adrenal cortex, and the pancreas and also an elevated serum gastrin level. An octreotide scan revealed 4 tumors in the upper abdomen. A selective arterial calcium stimulation test located the source of the hypergastrinemia to the area of the gastroduodenal and the superior mesenteric arteries. Total pancreatoduodenectomy was performed and conventional histopathologic examination revealed a well-differentiated cystic neuroendocrine tumor of the pancreas expressing glucagon and accompanied by several microadenomas. In addition, 3 suprapancreatic lymph nodes with gastrin-positive endocrine tissue were found. None of the pancreatic microadenomas expressed gastrin and no duodenal endocrine tumor was found despite careful macroscopic examination. Only after complete embedding of the duodenal and pancreatic tissue in 65 paraffin blocks, 2 microgastrinomas (0.45 and 0.8 mm in diameter) were identified in the duodenum. It is concluded that duodenal gastrinomas that give rise to lymph node metastases may be so tiny that they are easily overlooked in a routine examination and that systematic tissue monitoring is required to identify them.

Pancreatic endocrine neoplasms: epidemiology and prognosis of pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) are uncommon tumors with an annual incidence <1 per 100 000 person-years in the general population. The PETs that produce hormones resulting in symptoms are designated as functional. The majority of PETs are non-functional. Of the functional tumors, insulinomas are the most common, followed by gastrinomas. The clinical course of patients with PETs is variable and depends on the extent of the disease and the treatment rendered. Patients with completely resected tumors generally have a good prognosis, and aggressive surgical therapy in patients with advanced disease may also prolong survival. The epidemiology, prognosis, and established and novel prognostic markers of PETs are reviewed.

The role of somatostatin analogues in the treatment of neuroendocrine tumours

Neuroendocrine tumours belong to a heterogeneous family of neoplasms, originating in endocrine glands (such as the pituitary, parathyroid or the neuroendocrine adrenal glands), in endocrine islets (within the thyroid or pancreas) as well as in endocrine cells dispersed between exocrine cells throughout the digestive or respiratory tracts. The clinical behaviour of neuroendocrine tumours is variable; they may be functioning or not functioning, ranging from well-differentiated slow growing neuroendocrine tumours to poorly differentiated neuroendocrine tumours, which are highly aggressive malignant tumours. The development of somatostatin analogues as important diagnostic and treatment tools have revolutionised the clinical management of patients with neuroendocrine tumours. However, although symptomatic relief and stabilisation of tumour growth for various periods of time are observed in many patients treated with somatostatin analogues, tumour regression is rare. Development of new somatostatin analogues and new drug combination therapies should further improve the clinical management of these patients.

A prospective study of gastric carcinoids and enterochromaffin-like cell changes in multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome: identification of risk factors

CONTEXT

Multiple endocrine neoplasia type 1 (MEN1) patients frequently develop Zollinger-Ellison syndrome (ZES). These patients can develop proliferative changes of gastric enterochromaffin-like (ECL) cells and gastric carcinoids (ECL-cell tumors). ECL-cell changes have been extensively studied in sporadic ZES patients and can be precursor lesions of gastric carcinoids, but little is known about factors influencing their severity or development of carcinoids in MEN1/ZES patients.

OBJECTIVES

Our objective was to prospectively analyze ECL-cell changes and gastric carcinoids (ECL-cell tumors) in a large series of MEN1/ZES patients to detect risk factors and deduct clinical guidelines.

SETTING AND PATIENTS

Fifty-seven consecutive MEN1/ZES patients participated in this prospective study at two tertiary-care research centers.

INTERVENTIONS AND OUTCOME MEASURES

Assessment of MEN1, gastric hypersecretion, and gastroscopy with multiple biopsies was done according to a fixed protocol and tumor status. ECL-cell changes and alpha-human chorionic gonadotropin staining were assessed in each biopsy and correlated with clinical, laboratory, and MEN1 features.

RESULTS

ECL-cell proliferative changes were universally present, advanced changes in 53% and carcinoids in 23%. Gastric nodules are common and are frequently associated with carcinoids. Patients with high fasting serum gastrin levels, long disease duration, or a strong alpha-human chorionic gonadotropin staining in a biopsy are at higher risk for an advanced ECL-cell lesion and/or gastric carcinoid.

CONCLUSIONS

Gastric carcinoids and/or advanced ECL-cell changes are frequent in MEN1/ZES patients, and therefore, regular surveillance gastroscopy with multiple routine biopsies and biopsies of all mucosal lesions are essential. Clinical/laboratory data and biopsy results can be used to identify a subgroup of MEN1/ZES patients with a significantly increased risk for developing gastric carcinoids, allowing development of better surveillance strategies.

Surgical treatment of sporadic gastrinoma

Surgical therapy for sporadic gastrinoma profits from innovative pre- and intraoperative diagnostics. Preoperative gastrinoma localization is enhanced by sophisticated endoscopic ultrasonography, scintigraphic and arteriographic studies with hormone sampling. Thereby a concise surgical approach is guided and additional intraoperative control of success may be gained by endoscopic transillumination and measurement of stimulated gastrin levels.