Zollinger-Ellison syndrome. Clinical presentation in 261 patients

Gastric neuroendocrine neoplasms

Gastric neuroendocrine neoplasms (gNENs) display peculiar site-specific features among all NENs. Their incidence and prevalence have been rising in the past few decades. gNENs comprise gastric neuroendocrine carcinomas (gNECs) and gastric neuroendocrine tumours (gNETs), the latter further classified into three types. Type I anatype II gNETs are gastrin-dependent and develop in chronic atrophic gastritis and as part of Zollinger-Ellison syndrome within a multiple endocrine neoplasia type 1 syndrome (MEN1), respectively. Type III or sporadic gNETs develop in the absence of hypergastrinaemia and in the context of a near-normal or inflamed gastric mucosa. gNECs can also develop in the context of variable atrophic, relatively normal or inflamed gastric mucosa. Each gNEN type has different clinical characteristics and requires a different multidisciplinary approach in expert dedicated centres. Type I gNETs are managed mainly by endoscopy or surgery, whereas the treatment of type II gNETs largely depends on the management of the concomitant MEN1. Type III gNETs may require both locoregional approaches and systemic treatments; NECs are often metastatic and therefore require systemic treatment. Specific data regarding the systemic treatment of gNENs are lacking and are derived from the treatment of intestinal NETs and NECs. An enhanced understanding of molecular and clinical pathophysiology is needed to improve the management and outcomes of patients' gNETs.

Sporadic Zollinger-Ellison syndrome in a patient with isolated mesenteric gastrinoma

INTRODUCTION

Zollinger-Ellison syndrome (ZES) is due to a gastrin-producing neuroendocrine tumor (gastrinoma) with subsequent gastric acid hypersecretion, gastroesophageal reflux disease (GERD), peptic ulcers, and chronic diarrhea.

CASE PRESENTATION

A 40-year old patient presented with epigastric pain associated with diarrhea evolving for 10 years, he has been treated by acid-suppressive medications without substantial clinical improvement. Gastro-duodenal endoscopy was performed with gastric biopsies that showed peptic ulcerations, a serum gastrin assay that showed high levels exceeding 10 times the upper limit of the normal range. The abdominal contrast-enhanced computed tomography scan (CT-Scan) showed a solid-cystic mass with contrast enhancement in the right colon mesentery. The histopathological analysis of the resected mass showed a well-differentiated neuroendocrine tumor, and the diagnosis of a sporadic Zollinger-Ellison syndrome (ZES) was disclosed. Eighteen months after the surgical treatment the patient has no symptoms of the disease.

CLINICAL DISCUSSION

Patients with ZES present often with long-standing clinical symptoms with delayed diagnosis. The surgical resection of the causative gastrinoma remains the most effective therapeutic treatment.

CONCLUSION

Patients with refractory chronic diarrhea and epigastric pain should be suspected of having ZES in order to benefit from adequate clinical management.

Complete Esophageal Obstruction: A Rare Complication of Zollinger-Ellison Syndrome

Complete esophageal obstruction (CEO) is a rare phenomenon usually observed after receiving head and neck radiation. Zollinger-Ellison syndrome (ZES) is typically associated with minimal esophageal morbidity because of advancements in antisecretory medications. There are currently no documented reports of CEO in patients with ZES. Although surgeries are available for the treatment of CEO, there is no established method for endoscopic lumen restoration, given its rarity. This case documents potential sequala of modern-day patients with ZES.

Case report: Fundic gland polyps caused by long-term omeprazole use in a Maltese dog

Long-term use of proton-pump inhibitors can induce fundic gland polyps in the human stomach. However, this phenomenon has not been described in the veterinary literature. A 5-year-old intact female Maltese dog was referred to our hospital with chronic intermittent vomiting. The dog had been administered omeprazole (0.7-1.0 mg/kg PO q24 h) for the management of hydrocephalus for over 4 years; the omeprazole dose was increased to 10 mg/kg PO q24 h 8 months prior to presentation at referring hospital. Abdominal ultrasonography revealed marked thickening of the gastric wall with multi-lobulated, thickened folds. Subsequent endoscopy revealed marked polypoid lesions, and histological examination of the biopsy samples was consistent with the fundic gland polyps associated with proton-pump inhibitor use in humans. The lesions resolved after cessation of omeprazole, as assessed by ultrasonography. This report describes a case of fundic gland polyps following the long-term administration of omeprazole in a dog.

Ectopic Adrenocorticotropic Hormone-Producing Metastatic Gastrinoma: A Case Report

Pancreatic neuroendocrine tumors secreting gastrin and adrenocorticotropic hormone (ACTH) are rare. The presentation of the cases can be varied, making the diagnosis challenging and often delayed. Here, we present a patient who presented with severe hypokalemia and was found to have ectopic Cushing's syndrome. An abdominal CT scan showed a pancreatic lesion with metastatic liver disease. A biopsy of the liver lesion confirmed a metastatic neuroendocrine tumor. The final diagnosis was ectopic ACTH-producing metastatic gastrinoma. Twenty-four-hour urinary cortisol was significantly elevated at 9,790 mcg/24 hours. The excess hormonal secretion was successfully treated with ketoconazole and somatostatin analogs. She was further started on chemotherapy with capecitabine plus temozolomide, which has become the preferred chemotherapy treatment after the results of the recently completed trial. She also received Y90 therapy for metastatic liver disease. The prognosis of metastatic pancreatic neuroendocrine tumors is poor. Multidisciplinary combined therapies can help control disease and improve prognosis. We present an 18-month-long patient follow-up and a literature review of ectopic ACTH-producing metastatic gastrinomas.

A Rare Case of Hepatic Gastrinoma

Zollinger-Ellison syndrome (ZES) is a rare condition caused by gastrin-secreting neuroendocrine tumors known as gastrinomas. We present a case of hepatic ZES presenting as upper gastrointestinal (GI) bleeding in a 70-year-old female. Initial evaluation revealed the patient to be in severe sepsis with septic shock secondary to a urinary tract infection, and her hospitalization was complicated by hematemesis and melena in the setting of multiple duodenal ulcers. Subsequent investigations, including elevated gastrin levels and a somatostatin receptor scan, confirmed the diagnosis of gastrinoma.

European Neuroendocrine Tumor Society 2023 guidance paper for functioning pancreatic neuroendocrine tumour syndromes

This ENETS guidance paper aims to provide practical advice to clinicians for the diagnosis, treatment and follow-up of functioning syndromes in pancreatic neuroendocrine tumours (NET). A NET-associated functioning syndrome is defined by the presence of a clinical syndrome combined with biochemical evidence of inappropriately elevated hormonal levels. Different hormonal syndromes can be encountered in pancreatic NET patients, including insulinoma, gastrinoma as well as the rare glucagonoma, VIPoma, ACTHoma, PTHrPoma, carcinoid syndrome, calcitoninoma, GHRHoma and somatostatinoma. The recommendations provided in this paper focus on the biochemical, genetic and imaging work-up as well as therapeutic management of the individual hormonal syndromes in well-differentiated, grade 1-3, functioning NET with the primary tumour originating in the pancreas, and for specific subtypes also in the duodenum.

Gastrinoma With Relatively Low Gastrin Levels: A Case Report

Gastrinomas can often be cured with surgical removal if detected early enough. We present a case report where a patient was diagnosed with gastrinoma with relatively low serum gastrin levels after subsequent duodenojejunostomy, gastrojejunostomy, total gastrectomy, and cholecystectomy. With this case report, we hope to promote a higher level of awareness of pancreatic neuroendocrine (NE) tumors and educate clinicians on the full effects of proton pump inhibitor (PPI) use on patient workup, diagnostics, and care.

Successful Lifetime/Long-Term Medical Treatment of Acid Hypersecretion in Zollinger-Ellison Syndrome (ZES): Myth or Fact? Insights from an Analysis of Results of NIH Long-Term Prospective Studies of ZES

Analysis of the efficacy/pharmacology of long-term/lifetime medical treatment of acid hypersecretion in a large cohort of ZES patients in a prospective study. This study includes the results from all 303 patients with established ZES who were prospectively followed and received acid antisecretory treatment with either H2Rs or PPIs, with antisecretory doses individually titrated by the results of regular gastric acid testing. The study includes patients treated for short-term periods (<5 yrs), patients treated long-term (>5 yrs), and patients with lifetime treatment (30%) followed for up to 48 years (mean 14 yrs). Long-term/lifelong acid antisecretory treatment with H2Rs/PPIs can be successfully carried out in all patients with both uncomplicated and complicated ZES (i.e., with MEN1/ZES, previous Billroth 2, severe GERD). This is only possible if drug doses are individually set by assessing acid secretory control to establish proven criteria, with regular reassessments and readjustments. Frequent dose changes both upward and downward are needed, as well as regulation of the dosing frequency, and there is a primary reliance on the use of PPIs. Prognostic factors predicting patients with PPI dose changes are identified, which need to be studied prospectively to develop a useful predictive algorithm that could be clinically useful for tailored long-term/lifetime therapy in these patients.

Quantitative characterization of duodenal gastrinoma autofluorescence using multiphoton microscopy

BACKGROUND

Duodenal gastrinomas (DGASTs) are neuroendocrine tumors that develop in the submucosa of the duodenum and produce the hormone gastrin. Surgical resection of DGASTs is complicated by the small size of these tumors and the tendency for them to develop diffusely in the duodenum. Endoscopic mucosal resection of DGASTs is an increasingly popular method for treating this disease due to its low complication rate but suffers from poor rates of pathologically negative margins. Multiphoton microscopy can capture high-resolution images of biological tissue with contrast generated from endogenous fluorescence (autofluorescence [AF]) through two-photon excited fluorescence (2PEF). Second harmonic generation is another popular method of generating image contrast with multiphoton microscopy (MPM) and is a light-scattering phenomenon that occurs predominantly from structures such as collagen in biological samples. Some molecules that contribute to AF change in abundance from processes related to the cancer disease process (e.g., metabolic changes, oxidative stress, and angiogenesis).

STUDY DESIGN/MATERIALS AND METHODS

MPM was used to image 12 separate patient samples of formalin-fixed and paraffin-embedded duodenal gastrinoma slides with a second-harmonic generation (SHG) channel and four 2PEF channels. The excitation and emission profiles of each 2PEF channel were tuned to capture signal dominated by distinct fluorophores with well-characterized fluorescent spectra and known connections to the physiologic changes that arise in cancerous tissue.

RESULTS

We found that there was a significant difference in the relative abundance of signal generated in the 2PEF channels for regions of DGASTs in comparison to the neighboring tissues of the duodenum. Data generated from texture feature extraction of the MPM images were used in linear discriminant analysis models to create classifiers for tumor versus all other tissue types before and after principal component analysis (PCA). PCA improved the classifier accuracy and reduced the number of features required to achieve maximum accuracy. The linear discriminant classifier after PCA distinguished between tumor and other tissue types with an accuracy of 90.6%-93.8%.

CONCLUSIONS

These results suggest that multiphoton microscopy 2PEF and SHG imaging is a promising label-free method for discriminating between DGASTs and normal duodenal tissue which has implications for future applications of in vivo assessment of resection margins with endoscopic MPM.

ENETS standardized (synoptic) reporting for endoscopy in neuroendocrine tumors

Despite efforts from various endoscopy societies, reporting in the field of endoscopy remains extremely heterogeneous. Harmonisation of clinical practice in endoscopy has been highlighted by application of many clinical practice guidelines and standards pertaining to the endoscopic procedures and reporting are underlined. The aim of the proposed "standardised reporting" is to (1) facilitate recognition of gastrointestinal neuroendocrine neoplasms (NEN) on initial endoscopy, (2) to enable interdisciplinary decision making for treatment by a multidisciplinary team, (3) to provide a basis for a standardised endoscopic follow-up which allows detection of recurrence or progression reliably, (4) to make endoscopic reports on NEN comparable between different units, and (5) to allow research collaboration between NEN centres in terms of consistency of their endoscopic data. The ultimate goal is to improve disease management, patient outcome and reduce the diagnostic burden on the side of the patient by ensuring the highest possible diagnostic accuracy and validity of endoscopic exams and possibly interventions.

Validity of Secretin Stimulation Testing on Proton Pump Inhibitor Therapy for Diagnosis of Zollinger-Ellison Syndrome

INTRODUCTION

Zollinger-Ellison syndrome (ZES) is characterized by gastrinoma-induced hypergastrinemia causing excessive gastric acid secretion. Secretin stimulation tests (SSTs) are required for diagnosis in the majority of patients. Two case reports suggest that proton pump inhibitors (PPIs) cause false SST results. Consequently, PPIs are discontinued to allow hyperchlorhydria to recur; however, uncontrolled acidity can cause life-threatening complications in those with underlying undiagnosed ZES. The aim of this study was to determine whether PPIs influence the validity of SSTs for the diagnosis of ZES.

METHODS

A retrospective chart review was performed. Charts of patients who underwent SSTs were reviewed to determine whether they were performed on or off PPI and the test's accuracy by comparing the results with gold standard tests (diagnostic laboratory testing performed off PPI or surgical pathology consistent with gastrinoma). Sensitivity, specificity, and positive predictive value (PPV) of SST on PPI were calculated and results compared with SST off PPI using noninferiority analyses.

RESULTS

Twenty-eight patients corresponding to 29 SSTs were performed on PPI, and 70 patients corresponding to 107 SSTs were performed off PPI. Most of them were female and white and had multiple endocrine neoplasia type 1. We found no false-positive or false-negative SSTs on PPI. Sensitivity, specificity, and PPV of SSTs on PPI were determined to be noninferior to SSTs off PPI (P ≤ 0.05 for all).

DISCUSSION

In our cohort, SSTs on PPI compared with SSTs off PPI were noninferior for sensitivity, specificity, and PPV. These results suggest that PPI withdrawal before SSTs may not be necessary.

Gastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies

Zollinger-Ellison syndrome (ZES) associated with pancreatic or duodenal gastrinoma is characterized by gastric acid hypersecretion, which typically leads to gastroesophageal reflux disease, recurrent peptic ulcers, and chronic diarrhea. As symptoms of ZES are nonspecific and overlap with other gastrointestinal disorders, the diagnosis is often delayed with an average time between the onset of symptoms and final diagnosis longer than 5 years. The critical step for the diagnosis of ZES is represented by the initial clinical suspicion. Hypergastrinemia is the hallmark of ZES; however, hypergastrinemia might recognize several causes, which should be ruled out in order to make a final diagnosis. Gastrin levels > 1000 pg/mL and a gastric pH below 2 are considered to be diagnostic for gastrinoma; some specific tests, including esophageal pH-recording and secretin test, might be useful in selected cases, although they are not widely available. Endoscopic ultrasound is very useful for the diagnosis and the local staging of the primary tumor in patients with ZES, particularly in the setting of multiple endocrine neoplasia type 1. Some controversies about the management of these tumors also exist. For the localized stage, the combination of proton pump inhibitory therapy, which usually resolves symptoms, and surgery, whenever feasible, with curative intent represents the hallmark of gastrinoma treatment. The high expression of somatostatin receptors in gastrinomas makes them highly responsive to somatostatin analogs, supporting their use as anti-proliferative agents in patients not amenable to surgical cure. Other medical options for advanced disease are super-imposable to other neuroendocrine neoplasms, and studies specifically focused on gastrinomas only are scant and often limited to case reports or small retrospective series. The multidisciplinary approach remains the cornerstone for the proper management of this composite disease. Herein, we reviewed available literature about gastrinoma-associated ZES with a specific focus on differential diagnosis, providing potential diagnostic and therapeutic algorithms.

Multiple endocrine neoplasia type 1 (MEN-1) and neuroendocrine neoplasms (NENs)

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms with 6.4-times increasing age-adjusted annual incidence during the last four decades. NENs arise from neuroendocrine cells, which release hormones in response to neuronal stimuli and they are distributed into organs and tissues. The presentation and biological behaviour of the NENs are highly heterogeneous, depending on the organ. The increased incidence is mainly due to increased awareness and improved detection methods both in the majority of sporadic NENs (non-inherited), but also the inherited groups of neoplasms appearing in at least ten genetic syndromes. The most important one is multiple endocrine neoplasia type 1 (MEN-1), caused by mutations in the tumour suppressor gene MEN1. MEN-1 has been associated with different tumour manifestations of NENs e.g. pancreas, gastrointestinal tract, lungs, thymus and pituitary. Pancreatic NENs tend to be less aggressive when arising in the setting of MEN-1 compared to sporadic pancreatic NENs. There have been very important improvements over the past years in both genotyping, genetic counselling and family screening, introduction and validation of various relevant biomarkers, as well as newer imaging modalities. Alongside this development, both medical, surgical and radionuclide treatments have also advanced and improved morbidity, quality of life and mortality in many of these patients. Despite this progress, there is still space for improving insight into the genetic and epigenetic factors in relation to the biological mechanisms determining NENs as part of MEN-1. This review gives a comprehensive update of current evidence for co-occurrence, diagnosis and treatment of MEN-1 and neuroendocrine neoplasms and highlight the important progress now finding its way to international guidelines in order to improve the global management of these patients.

Clinical aspects of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome characterized by the co-occurrence of primary hyperparathyroidism, duodenopancreatic neuroendocrine tumours (NETs) and/or pituitary adenomas. MEN1 can predispose patients to other endocrine and non-endocrine tumours, such as cutaneous tumours, central nervous system tumours and breast cancer. Endocrine tumours in patients with MEN1 differ from sporadic tumours in that they have a younger age at onset, present as multiple tumours in the same organ and have a different clinical course. Therefore, patients with overt MEN1 and those who carry a MEN1 mutation should be offered tailored biochemical and imaging screening to detect tumours and evaluate their progression over time. Fortunately, over the past 10 years, knowledge about the clinical phenotype of these tumours has markedly progressed, thanks to the implementation of national registries, particularly in France and the Netherlands. This Review provides an update on the clinical management of MEN1-related tumours. Epidemiology, the clinical picture, diagnostic work-up and the main lines of treatment for MEN1-related tumours are summarized. Controversial therapeutic aspects and issues that still need to be addressed are also discussed. Moreover, special attention is given to MEN1 manifestations in children and adolescents.

Multiple Endocrine Neoplasia Type 1 and the Pancreas: Diagnosis and Treatment of Functioning and Non-Functioning Pancreatic and Duodenal Neuroendocrine Neoplasia within the MEN1 Syndrome - An International Consensus Statement

The better understanding of the biological behavior of multiple endocrine neoplasia type 1 (MEN1) organ manifestations and the increase in clinical experience warrant a revision of previously published guidelines. Duodenopancreatic neuroendocrine neoplasias (DP-NENs) are still the second most common manifestation in MEN1 and, besides NENs of the thymus, remain a leading cause of death. DP-NENs are thus of main interest in the effort to reevaluate recommendations for their diagnosis and treatment. Especially over the last 2 years, more clinical experience has documented the follow-up of treated and untreated (natural-course) DP-NENs. It was the aim of the international consortium of experts in endocrinology, genetics, radiology, surgery, gastroenterology, and oncology to systematically review the literature and to present a consensus statement based on the highest levels of evidence. Reviewing the literature published over the past decade, the focus was on the diagnosis of F- and NF-DP-NENs within the MEN1 syndrome in an effort to further standardize and improve treatment and follow-up, as well as to establish a "logbook" for the diagnosis and treatment of DP-NENs. This shall help further reduce complications and improve long-term treatment results in these rare tumors. The following international consensus statement builds upon the previously published guidelines of 2001 and 2012 and attempts to supplement the recommendations issued by various national and international societies.

Primary hepatic gastrinoma being diagnosed preoperatively: a case report and literature review

Background

A majority of gastrinomas causing Zollinger–Ellison syndrome are located in the duodenum or pancreas. Primary hepatic gastrinomas are rare and difficult to diagnose. We report a rare case of primary hepatic gastrinoma, which could be diagnosed preoperatively.

Case presentation

A 29-year-old man with a 55-mm tumor in segments 5 and 6 (S 5/6) of the liver was admitted to our hospital. After thorough investigations, he was treated for a suspected inflammatory pseudotumor and advised to undergo routine follow-up. Two years later, he revisited our hospital with a complaint of abdominal pain, vomiting, and diarrhea. Upper gastrointestinal endoscopy revealed multiple duodenal ulcers. His serum gastrin level was 2350 pg/mL (normal: 37–172 pg/mL), suggesting Zollinger–Ellison syndrome. Abdominal computed tomography showed a 78-mm hypervascular tumor with cystic degeneration in the S 5/6 region of the liver, with a potential to increase over time. The tumor showed hypointensity on T2-weighted and hyperintensity on diffusion-weighted abdominal contrast-enhanced magnetic resonance imaging. Somatostatin receptor scintigraphy (SRS) only detected a hepatic tumor. No tumors in the gastrinoma triangle were detected by endoscopic ultrasonography. Hence, selective arterial calcium injection (SACI) test was performed to determine the location of the gastrinoma. The serum gastrin concentration increased from 4620 pg/mL to 23,600 pg/mL at 20 s after calcium gluconate injection into the proper hepatic artery. Conversely, no effect on serum gastrin level was observed after the injection into any other arteries. Extended right hepatic lobectomy and cholecystectomy were performed after percutaneous transhepatic portal vein embolization. A histopathological examination of the liver tumor revealed a gastrinoma. The patient’s serum gastrin concentration on postoperative day 1 decreased to 65 pg/mL.

Conclusion

We report a surgical case of primary hepatic gastrinoma correctly diagnosed preoperatively. The patient underwent extended right hepatic lobectomy, resulting in a histological definitive diagnosis of primary hepatic gastrinoma.

Perspectives on the current pharmacotherapeutic strategies for management of functional neuroendocrine tumor syndromes

Introduction: In the past, controlling the hormone-excess-state was the main determinant of survival in Functional-Neuroendocrine-Neoplasm-syndromes (F-NENs). This was difficult because the pharmacological-armamentarium available was limited. Recently, new therapeutic strategies have increased but it also generated controversies/uncertainties.Areas covered: The authors briefly review: established/proposed F-NENs; the rationale for treatments; the recommended initial-pharmacotherapeutic-approach to controlling F-NENs hormone-excess-state; the secondary-approaches if the initial approach fails or resistance develops; and the approach to deal with the malignant nature of the NEN. Also discussed are controversies/uncertainties related to new treatments.Expert opinion: Unfortunately, except for patients with insulinomas (>90-95%), gastrinomas (<20-40%), a minority with the other F-panNENs and 0-<1% with Carcinoid-syndrome is curative-surgery possible. Except for insulinomas, gastrinomas, and ACTHomas, long-acting somatostatin-analogs are the initial-pharmacological-treatments for hormone-excess-state. For insulinomas prior to surgery/malignancy, diazoxide is the initial drug-treatment; for gastrinomas, oral PPIs; and for ACTHomas, steroidogenesis inhibitors. There are now several secondary pharmacotherapeutic treatments. Surgery and liver-directed therapies also have a role in selected patients. Particularly promising is the recent results with PRRT for the hormone-excess-state, independent of its anti-growth effect. The sequence to use various agents and the approach to syndrome diagnosis while taking various agents remains unclear/controversial in many cases.

Differential Diagnosis and Management of Diarrhea in Patients with Neuroendocrine Tumors

Diarrhea is a recurrent symptom in patients with neuroendocrine tumors (NETs) and can represent different etiologies; thus, differential diagnosis is challenging. This paper distinguishes the different causes of chronic diarrhea in patients with gastroenteropancreatic NETs, with the aim to identify the most appropriate therapeutic approach. Underlying causes of diarrhea can be multifactorial, including not only diarrhea that is related to specific hormonal hypersecretory syndromes, but also diarrhea that is secondary to the following: extensive surgery which can cause pancreatic exocrine insufficiency or short bowel syndrome, treatment with somatostatin analogs or other antineoplastic agents, and bile acid malabsorption. After initial management of diarrhea with general treatments (dietary modification, use of antidiarrheals), a proper differential diagnosis is necessary to treat patients with specific etiology-driven therapeutic approaches, such as somatostatin analogs, pancreatic enzyme replacement therapy, and tryptophan hydroxylase inhibitors. In conclusion, NETs should be considered in the differential diagnosis of patients suffering from chronic diarrhea, after the exclusion of more common etiologies. Furthermore, physicians should keep in mind that several different etiologies might be responsible for diarrhea occurrence in NET patients. A prompt diagnosis of the actual cause of diarrhea is necessary to guide the treatment and a multidisciplinary approach is mandatory.

Multiple Endocrine Neoplasia: Spectrum of Abdominal Manifestations

OBJECTIVE. Multiple endocrine neoplasia (MEN) syndromes are autosomal-dominant genetic disorders that predispose two or more organs of the endocrine system to tumor development. Although the diagnosis relies on clinical and serologic findings, imaging provides critical information for surgical management with the ultimate goal of complete tumor resection. CONCLUSION. This article reviews abdominal neoplasms associated with the various subtypes of MEN syndromes, with a focus on clinical presentation and characteristic imaging features.

Cytopathological evaluation of potential malignancy of duodenal gastrinoma using aspiration smears from two patients' resected tumors (NET G1, NET G2): A case report

Sporadic gastrin-producing neuroendocrine tumors (NETs) of the duodenum present with either Zollinger-Ellison syndrome or unspecific syndromes. Ki-67 scoring in cytopathology is an alternative approach for establishing the gastrinoma grade. Although the majority of NETs, including gastrinomas, occur in the duodenum, most research regarding the Ki-67 index is focused on tumors of pancreatic origin. To the best of our knowledge, there is no study on the Ki-67 index for cytological analysis of duodenal gastrinoma. The current report presents two cases of a 56-year-old man and a 66-year-old woman with NET G1 and G2 gastrinoma, respectively, arising in the duodenal bulb. The present report focused on the differences in nuclear pleomorphism and Ki-67 index between these two cases.

Duodenal emergencies: utility of multidetector CT with 2D multiplanar reconstructions for challenging but critical diagnoses

Duodenal pathology is an infrequent cause of acute abdominal pain for which patients present to the emergency department. Critical pathology on multidetector CT (MDCT) may be overlooked if the radiologist does not carefully evaluate the duodenum as part of the search pattern. Optimal MDCT protocols include intravenous contrast with multiplanar reconstructions (MPRs). A variety of etiologies ranging from infection to malignancy can involve the duodenum, for which interrogation with MPRs is most helpful given the anatomy and complex relationship with surrounding structures. The purpose of this review article is to highlight the importance of CT acquisition with multiplanar reconstructions and review the spectrum of emergent duodenal pathology, with the goal of ensuring accurate and timely diagnosis to best guide patient management.

Gastrinoma in multiple endocrine neoplasia type 1 after total pancreatectomy: A case report

RATIONALE

Surgery for patients with multiple endocrine neoplasia type 1(MEN-1) related gastrinoma remains controversial and total pancreatectomy (TP) has rarely been performed. We reported a case of patient with MEN-1 related gastrinoma treated by TP.

PATIENT CONCERNS

A 46-year-old female was admitted to our hospital due to abdominal distension and diarrhea for 2 years. The patient underwent pituitary tumor resection and kidney stone lithotripsy 10 years ago.

DIAGNOSES

Abdominal computed tomography showed single lesion in the duodenum and multiple lesions throughout the pancreas. The patient's gastrin level was significantly increased (1080 pg/ml). These findings in combination with the pituitary tumor history suggested the presence of gastrinoma associated with MEN-1 syndrome.

INTERVENTION

An exploratory laparotomy was performed. Intraoperative ultrasound confirmed the numerous tumors diffusely distributed throughout the pancreas and the patient eventually underwent TP.

OUTCOMES

Twelve months later, the patient was hospitalized again for anastomotic fistula and underwent a partial gastrectomy, small bowel resection and drainage of the abscess. One month later, she received gastrostomy and jejunostomy due to digestive tract fistula, and died a month later (14 months after TP).

LESSONS

There still might be the possibility of recurrence even after radical surgical resection of gastrinomas, and we suggest the need to measure the basal acid output and maintain regular anti-acid therapy in the long-term follow-up of patients with MEN-1 related gastrinoma.

Insights into Effects/Risks of Chronic Hypergastrinemia and Lifelong PPI Treatment in Man Based on Studies of Patients with Zollinger-Ellison Syndrome

The use of proton pump inhibitors (PPIs) over the last 30 years has rapidly increased both in the United States and worldwide. PPIs are not only very widely used both for approved indications (peptic ulcer disease, gastroesophageal reflux disease (GERD), Helicobacter pylori eradication regimens, stress ulcer prevention), but are also one of the most frequently off-label used drugs (25–70% of total). An increasing number of patients with moderate to advanced gastroesophageal reflux disease are remaining on PPI indefinitely. Whereas numerous studies show PPIs remain effective and safe, most of these studies are <5 years of duration and little data exist for >10 years of treatment. Recently, based primarily on observational/epidemiological studies, there have been an increasing number of reports raising issues about safety and side-effects with very long-term chronic treatment. Some of these safety issues are related to the possible long-term effects of chronic hypergastrinemia, which occurs in all patients taking chronic PPIs, others are related to the hypo-/achlorhydria that frequently occurs with chronic PPI treatment, and in others the mechanisms are unclear. These issues have raised considerable controversy in large part because of lack of long-term PPI treatment data (>10–20 years). Zollinger–Ellison syndrome (ZES) is caused by ectopic secretion of gastrin from a neuroendocrine tumor resulting in severe acid hypersecretion requiring life-long antisecretory treatment with PPIs, which are the drugs of choice. Because in <30% of patients with ZES, a long-term cure is not possible, these patients have life-long hypergastrinemia and require life-long treatment with PPIs. Therefore, ZES patients have been proposed as a good model of the long-term effects of hypergastrinemia in man as well as the effects/side-effects of very long-term PPI treatment. In this article, the insights from studies on ZES into these controversial issues with pertinence to chronic PPI use in non-ZES patients is reviewed, primarily concentrating on data from the prospective long-term studies of ZES patients at NIH.

Surgical management of Zollinger-Ellison syndrome: Classical considerations and current controversies

Zollinger-Ellison syndrome (ZES) is characterized by gastric acid hypersecretion causing severe recurrent acid-related peptic disease. Excessive secretion of gastrin can now be effectively controlled with powerful proton pump inhibitors, but surgical management to control gastrinoma itself remains controversial. Based on a thorough literature review, we design a surgical algorithm for ZES and list some significant consensus findings and recommendations: (1) For sporadic ZES, surgery should be routinely undertaken as early as possible not only for patients with a precisely localized diagnosis but also for those with negative imaging findings. The surgical approach for sporadic ZES depends on the lesion location (including the duodenum, pancreas, lymph nodes, hepatobiliary tract, stomach, and some extremely rare sites such as the ovaries, heart, omentum, and jejunum). Intraoperative liver exploration and lymphadenectomy should be routinely performed; (2) For multiple endocrine neoplasia type 1-related ZES (MEN1/ZES), surgery should not be performed routinely except for lesions > 2 cm. An attempt to perform radical resection (pancreaticoduodenectomy followed by lymphadenectomy) can be made. The ameliorating effect of parathyroid surgery should be considered, and parathyroidectomy should be performed first before any abdominal surgery for ZES; and (3) For hepatic metastatic disease, hepatic resection should be routinely performed. Currently, liver transplantation is still considered an investigational therapeutic approach for ZES. Well-designed prospective studies are desperately needed to further verify and modify the current considerations.

Insights into the biology and treatment strategies of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are the second most common primary pancreatic neoplasms after pancreatic ductal adenocarcinoma. PNETs present with widely various clinical manifestation and unfavorable survival rate. The recent advances in next generation sequencing have significantly increased our understanding of the molecular landscape of PNETs and help guide the development of targeted therapies. This review intends to outline a holistic picture of the tumors by discussing current understanding of clinical presentations, up-to-date treatment strategies, novel mouse models, and molecular biology of PNETs. Furthermore, we will provide insight into the future development of more effective targeted therapies that are necessary to manage PNETs.

Zollinger Ellison Syndrome in a Patient with Multiple Endocrine Neoplasia Type 1: A Classic Presentation

Zollinger Ellison Syndrome (ZES) is characterized by a wide spectrum of conditions including severe gastroesophageal reflux disease, peptic ulcer disease, watery diarrhea, and weight loss. We present a case of a 60-year-old woman being evaluated for severe dyspepsia, vomiting, and chronic diarrhea, who was diagnosed to have ZES associated with a pancreatic neuroendocrine tumor, in the setting of multiple endocrine neoplasia (MEN) type 1. Although cases of ZES have been reported previously, we believe that our case is a classic presentation of ZES diagnosed on the basis of typical radiologic, endoscopic, and endosonographic features.

Prospective Evaluation of Results of Reoperation in Zollinger-Ellison Syndrome

OBJECTIVE

To determine the role of reoperation in patients with persistent or recurrent Zollinger-Ellison Syndrome (ZES).

BACKGROUND

Approximately, 0% to 60% of ZES patients are disease-free (DF) after an initial operation, but the tumor may recur.

METHODS

A prospective database was queried.

RESULTS

A total of 223 patients had an initial operation for possible cure of ZES and then were subsequently evaluated serially with cross sectional imaging-computed tomography, magnetic resonance imaging, ultrasound, more recently octreoscan-and functional studies for ZES activity. The mean age at first surgery was 49 years and with an 11-year mean follow-up 52 patients (23%) underwent reoperation when ZES recurred with imageable disease. Results in this group are analyzed in the current report. Reoperation occurred on a mean of 6 years after the initial surgery with a mean number of reoperations of 1 (range 1-5). After reoperation 18/52 patients were initially DF (35%); and after a mean follow-up of 8 years, 13/52 remained DF (25%). During follow-up, 9/52 reoperated patients (17%) died, of whom 7 patients died a disease-related death (13%). The overall survival from first surgery was 84% at 20 years and 68% at 30 years. Multiple endocrine neoplasia type 1 status did not affect survival, but DF interval and liver metastases did.

CONCLUSIONS

These results demonstrate that a significant proportion of patients with ZES will develop resectable persistent or recurrent disease after an initial operation. These patients generally have prolonged survival after reoperation and 25% can be cured with repeat surgery, suggesting all ZES patients postresection should have systematic imaging, and if tumor recurs, advise repeat operation.

Overview of Genetically Determined Diseases/Multiple Endocrine Neoplasia Syndromes Predisposing to Endocrine Tumors

In this chapter, we present an overview of multiple endocrine neoplasia syndromes including their most important clinical and molecular features. Multiple endocrine neoplasia type 1 and 2 syndromes (MEN1 and MEN2) are discussed in detail. Syndromes that are presented in other chapters are only briefly mentioned. We discuss the relevance of germline gene alterations in apparently sporadic endocrine tumors, e.g., medullary thyroid cancer, primary hyperparathyroidism, and neuroendocrine tumors. McCune-Albright syndrome that only exists in non-hereditary, sporadic forms is also discussed in detail, as tumors of several endocrine organs can develop in the same individual.

Gastric Neuroendocrine Tumor and Duodenal Gastrinoma With Chronic Autoimmune Atrophic Gastritis

Our group observed the first case of synchronous gastric neuroendocrine tumor (NET) and duodenal gastrinoma with autoimmune chronic atrophic gastritis (CAG), in the absence of Helicobacter pylori infection. Demographic, clinical, endoscopic, and pathologic data were abstracted from the electronic medical record at Mount Sinai Hospital from 2013 to 2015. The patient's anonymity was carefully protected, and informed consent was obtained for publication of protected health information. A 53-year-old woman with hypertension presented to Mount Sinai Hospital in June 2013 for a second opinion for management of gastric and duodenal NETs. After evaluation by gastroenterology and surgery, repeat upper endoscopy with ultrasound and fine-needle aspiration revealed multiple diminutive type I gastric NETs and 2 duodenal NETs, against a background of autoimmune CAG, with biopsy pathology negative for H. pylori. She subsequently underwent a transduodenal resection of the duodenal NETs, confirming low-grade, gastrin-positive, stage T2 duodenal NET. On routine follow-up over the next 2 years, clinical, radiographic, and endoscopic surveillance revealed no recurrent or metastatic gastric or duodenal disease. This first report of synchronous duodenal gastrinoma and gastric NET in the setting of autoimmune CAG can broaden our understanding of gastric NET pathophysiology.

Zollinger-Ellison syndrome. Case report

Introduction: The Zollinger-Ellison syndrome (ZES) is a pathology caused by a neuroendocrine tumor, usually located in the pancreas or the duodenum, which is characterized by elevated levels of gastrin, resulting in an excessive production of gastric acid.Case presentation: A 42-year-old female patient with a history of longstanding peptic ulcer disease, who consulted due to persistent epigastric pain, melena and signs of peritoneal irritation.  Perforated peptic ulcer was suspected, requiring emergency surgical intervention. Subsequently, a tumor lesion in the head of the pancreas was documented and managed with Whipple procedure. The pathology results reported a tumor suggestive of neuroendocrine neoplasm.Discussion: The Zollinger-Ellison syndrome occurs in 0.1 to 3 people per 1 000 000 inhabitants worldwide and is predominant in women between 20 and 50 years of age. It usually appears as a refractory acid-peptic disease or as a complication of gastric acid hypersecretion. Medical therapy is the standard management, being proton pump inhibitors (PPI) the most effective option. Surgery is recommended for sporadic ZES.Conclusions: ZES has a low incidence rate. It is rarely considered in the differential diagnosis of chronic epigastric pain and high clinical suspicion is required to achieve adequate management. This article is highly relevant as it presents a confirmed clinical case of ZES in Colombia, highlighting the importance of producing local scientific literature to improve the diagnosis and treatment of this pathology.

Neoplasms of the Neuroendocrine Pancreas: An Update in the Classification, Definition, and Molecular Genetic Advances

This review focuses on discussing the main modifications of the recently published 2017 WHO Classification of Neoplasms of the Neuroendocrine Pancreas (panNEN). Recent updates separate pancreatic neuroendocrine tumors into 2 broad categories: well-differentiated pancreatic neuroendocrine tumors (panNET) and poorly differentiated pancreatic neuroendocrine carcinoma (panNEC), and incorporates a new subcategory of "well-differentiated high-grade NET (G3)" to the well-differentiated NET category. This new classification algorithm aims to improve the prediction of clinical outcomes and survival and help clinicians select better therapeutic strategies for patient care and management. In addition, these neuroendocrine neoplasms are capable of producing large quantity of hormones leading to clinical hormone hypersecretion syndromes. These functioning tumors include, insulinomas, glucagonomas, somatostatinomas, gastrinomas, VIPomas, serotonin-producing tumors, and ACTH-producing tumors. Although most panNENs arise as sporadic diseases, a subset of these heterogeneous tumors present as parts on inherited genetic syndromes, such as multiple endocrine neoplasia type 1, von Hippel-Lindau, neurofibromatosis type 1, tuberous sclerosis, and glucagon cell hyperplasia and neoplasia syndromes. Characteristic clinical and morphologic findings for certain functioning and syndromic panNENs should alert both pathologists and clinicians as appropriate patient management and possible genetic counseling may be necessary.

The impact of failure to achieve symptom control after resection of functional neuroendocrine tumors: An 8-institution study from the US Neuroendocrine Tumor Study Group

BACKGROUND

The goals of resection of functional neuroendocrine tumors (NETs) are two-fold: Oncological benefit and symptom control. The interaction between the two is not well understood.

METHODS

All patients with functional NETs of the pancreas, duodenum, and ampulla who underwent curative-intent resection between 2000 and 2016 were identified. Using Cox regression analysis, factors associated with reduced recurrence-free survival (RFS) were identified.

RESULTS

Two-hundred and thirty patients underwent curative-intent resection. Fifty-three percent were insulinomas, 35% gastrinomas, and 12% were other types. Twenty-one percent had a known genetic syndrome, 23% had lymph node (LN) positivity, 80% underwent an R0 resection, and 14% had no postoperative symptom improvement (SI). Factors associated with reduced RFS included noninsulinoma histology, the presence of a known genetic syndrome, LN positivity, R1 margin, and lack of SI. On multivariable analysis, only the failure to achieve SI following resection was associated with reduced RFS. Considering only those patients with an R0 resection, failure to achieve SI was associated with worse 3-year RFS compared with patients having SI (36% vs 80%; P = 0.006).

CONCLUSIONS

Failure to achieve symptomatic improvement after resection of functional NETs is associated with worse RFS. These patients may benefit from short-interval surveillance imaging postoperatively to assess for earlier radiographical disease recurrence.

Gastrinomas: Medical or Surgical Treatment

This article reviews the role of surgical and medical management in patients with Zollinger-Ellison syndrome (ZES) due to a gastrin-secreting neuroendocrine tumor (gastrinoma). It concentrates on the status at present but also briefly reviews the changes over time in treatment approaches. Generally, surgical and medical therapy are complementary today; however, in some cases, such as patients with ZES and multiple endocrine neoplasia type 1, the treatment approach remains controversial.

Large primary hepatic gastrinoma in young patient treated with trisegmentectomy: A case report and review of the literature

Primary hepatic gastrinoma is a rare disease, with fewer than 40 cases reported in the medical literature. Because it is located in an organ in which metastases are common, its diagnosis is difficult. We report a case of a 19 years old male patient with a history of gastric ulcers since the age of nine. Following gastric surgery, an antrectomy and a vagotomy, there was some alleviation of symptoms. Subsequently, the patient reported various intermittent episodes of diarrhea, diffuse abdominal pain, and vomiting. The patient underwent tomography, which revealed the presence of a hepatic mass measuring 19.5 cm × 12.5 cm × 17 cm. Primary hepatic gastrinoma was diagnosed based on laboratory examinations that indicated hypergastrinemia and a positron emission tomography/magnetic resonance study with somatostatin analogue that confirmed the liver as the primary site. After hepatic trisegmentectomy (II, III, IV, V, VIII), the patient’s symptoms improved. The case is notable for the presence of a rare tumor with uncommon dimensions.

A Rare Cause of Abdominal Pain and Mass in an 18-Year-Old Patient: A Diagnostic Dilemma

We present a case of an 18-year-old male who presented with complains of abdominal pain, nausea and vomiting for 2 years. An esophagogastroduodenoscopy (EGD) revealed a 3 mm nodule on the lesser curvature of the stomach and prominent gastric folds. Biopsy of the nodule revealed a well-differentiated neuroendocrine tumor (NET) in lamina prop with focal extension into muscularis mucosa consistent with a gastric carcinoid. Tumor cells stained with neuron-specific enolase (NSE), chromogranin and synaptophysin only. The prominent gastric fold biopsy revealed gastric fundic mucosa with mucosal edema and focal mild chronic inflammation. Serum gastrin level was found to be 2,083 pg/mL. Abdomen CT and endoscopic ultrasound (EUS) revealed a mass near the pancreatic neck. These findings were consistent with a functional gastrin producing well-differentiated grade 1 neuroendocrine neoplasm (gastrinoma). The patient underwent exploratory laparotomy with resection of the mass and resulting in normalization of gastrin levels.

Imaging Manifestations of Peptic Ulcer Disease on Computed Tomography

Although the overall prevalence of peptic ulcer disease (PUD) has decreased in modern times, its actual incidence may be underestimated owing to the nonspecific clinical presentations patients' manifest. The potential lethal complications that can result from PUD include life-threatening abdominal hemorrhage and bowel perforation that result in significant morbidity and mortality. Computed tomography (CT) imaging historically lacks specificity in detecting PUD-related pathology in the stomach and proximal small bowel segments. Therefore, these are potential pitfalls in the radiologist's search pattern on abdominopelvic CT imaging. This article highlights imaging features of uncomplicated PUD on CT imaging in order to allow for early detection of this disease process on imaging and the prevention of potential high-grade complications by recommending esophagogastroduodenoscopy.

Hormone secreting gastro-entero-pancreatic neuroendocrine neoplasias (GEP-NEN): When to consider, how to diagnose?

Neuroendocrine neoplasms of the digestive system (GEP-NEN) represent a heterogeneous group of malignancies with various clinical presentation and prognosis. GEP-NENs can potentially affect all organs of the gastrointestinal tract; characteristically they share the biological property to produce and secrete peptides and neuroamines. About 30% of GEP-NENs are hormonally active and can cause specific clinical syndromes. The clinical presentation mainly depends on the primary site of the tumor and its functionality. Because of the wide spectrum of clinical symptoms and their misperceived rarity, diagnosis of GEP-NENs is often delayed for years and tumors are detected first in an advanced stage. Early identification of a specific hormonal syndrome can significantly impact tumor diagnosis and treatment, moreover the preoperative management of NEN hormonal release avoids potential life threatening hormonal crisis. However, GEP-NEN diagnostic work-up is challenging, it requires a multidisciplinary team and needs particular experience; standardized protocols and clinical experience are essential for a proper endocrine diagnostic work-up. In addition to the biochemical diagnostic, further radiologic and endoscopic imaging modalities are required moreover, somatostatin-receptor based functional imaging, using either Octreotide-scintigraphy or novel PET-based techniques with specific isotopes like Ga⁶⁸-DOTA-octreotate, plays an important role for the detection of the primary tumor as well as for the evaluation of the tumor extent.

Diagnosis and Management of Upper Gastrointestinal Neuroendocrine Tumors

Upper gastrointestinal neuroendocrine tumors (NETs) are rare tumors which are increasingly recognised by practising endoscopists. After confirmation by endoscopic biopsies of these focal lesions, many questions may arise. As NETs are less frequently encountered compared to other malignancies or gastrointestinal pathology, many endoscopists may not fully understand the natural history, diagnosis and management of these tumors. In this review, we aim to update the practising endoscopist on the key clinical features and management of patients with upper gastrointestinal NET.

Diagnosis of Zollinger-Ellison syndrome in the era of PPIs, faulty gastrin assays, sensitive imaging and limited access to acid secretory testing

In recent years the diagnosis of Zollinger-Ellison syndrome (ZES) has become increasingly controversial with several new approaches and criteria proposed, differing from the classical biochemical criterion of inappropriate hypergastrinemia (i.e., hypergastrinemia in the presence of hyperchlorhydria) (Table 1). These changes have come about because of the difficulty and potential dangers of stopping proton pump inhibitors (PPIs) for gastric acid analysis; the recognition than many of the current assays used to assess gastrin concentrations are unreliable; the development of sensitive imaging modalities that detect neuroendocrine tumors (NETs) including an increasing number of the primary gastrinomas; the increased use of percutaneous or endoscopic ultrasound (EUS)-directed biopsies/cytology and the general lack of availability of acid secretory testing. In this article we will discuss the basis for these controversies, review the proposed changes in diagnostic approaches and make recommendations for supporting the diagnosis of ZES in the modern era.

Catching the Zebra: Clinical Pearls and Pitfalls for the Successful Diagnosis of Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome (ZES) results from an ectopic gastrin-secreting tumor leading to peptic ulcer disease, reflux, and chronic diarrhea. While early recognition portends an excellent prognosis with >80% survival at 15 years, symptoms are often nonspecific making the diagnosis difficult to establish. Diagnosis involves a series of tests, including fasting gastrin, gastric pH, chromogranin A, and secretin stimulation. Performing these tests in the correct sequence and at the proper time is essential to avoid inaccurate results. Tumor localization is equally nuanced. Although providers have classically used ¹¹¹indium-radiolabeled octreotide with somatostatin receptor scintigraphy to evaluate tumor size and metastases, recent studies have shown superior results with newer imaging modalities. In particular, ⁶⁸gallium (⁶⁸Ga)-labeled somatostatin radiotracers (i.e., ⁶⁸Ga-DOTATOC, ⁶⁸Ga-DOTANOC and ⁶⁸Ga-DOTATATE) used with positron emission tomography/computed tomography can provide excellent results. Endoscopic ultrasound is another useful modality, particularly in patients with ZES in the setting of multiple endocrine neoplasia type 1. This review aims to provide clinicians with an overview of ZES with a focus on both clinical presentation and the proper utilization of the various biochemical and imaging tests available.