Zollinger-Ellison syndrome: classical considerations and current controversies

Agonists, Antagonists and Receptors of Somatostatin: Pathophysiological and Therapeutical Implications in Neoplasias

Somatostatin is a peptide that plays a variety of roles such as neurotransmitter and endocrine regulator; its actions as a cell regulator in various tissues of the human body are represented mainly by inhibitory effects, and it shows potent activity despite its physiological low concentrations. Somatostatin binds to specific receptors, called somatostatin receptors (SSTRs), which have different tissue distributions and associated signaling pathways. The expression of SSTRs can be altered in various conditions, including tumors; therefore, they can be used as biomarkers for cancer cell susceptibility to certain pharmacological agents and can provide prognostic information regarding disease evolution. Moreover, based on the affinity of somatostatin analogs for the different types of SSTRs, the therapeutic range includes conditions such as tumors, acromegaly, post-prandial hypotension, hyperinsulinism, and many more. On the other hand, a number of somatostatin antagonists may prove useful in certain medical settings, based on their differential affinity for SSTRs. The aim of this review is to present in detail the principal characteristics of all five SSTRs and to provide an overview of the associated therapeutic potential in neoplasias.

Modern Management of Gastric Neuroendocrine Neoplasms

OPINION STATEMENT

Gastric neuroendocrine neoplasms (G-NENs) are a heterogeneous group of tumors that broadly fall into two groups. The first group, driven by oversecretion of gastrin, are generally multifocal, small, and behave indolently with a low (but non-zero) risk of progression and metastatic spread. They are conventionally categorized into type 1, with endogenous gastric-based overproduction of gastrin, and type 2 G-NEN, with overproduction of gastrin from an extra-gastric gastrin-secreting tumor. The second group, termed type 3 G-NEN, occur spontaneously and are potentially more aggressive, having a clinical course analogous to other neuroendocrine tumors of the gastrointestinal tract. Type 1 G-NEN can be managed with endoscopic surveillance and resection of visible lesions with great success, reserving surgery for the rare high-risk lesion, whereas surgical resection of the causative gastrin-secreting tumor in type 2 G-NEN is usually curative. Type 3 G-NEN is usually managed with formal surgical resection but there is growing evidence that limited surgery or even endoscopic resection in appropriately selected patients with low risk is both safe and effective. A novel subtype of G-NEN, associated with long-term proton pump inhibitor usage, is increasing in incidence. The pathophysiology seems to parallel type 1 G-NEN. In the setting of metastatic disease, which can occur in any subtype but is most common by far in type 3 G-NEN, the lack of trial data unique to G-NEN results in extrapolation of strategies and agents for treatment of non-gastric neuroendocrine disease. The rapid pace of development in this area is likely to benefit the metastatic G-NEN patient as well. As treatment is predicate on type of G-NEN, establishing the etiology of the lesion is crucial but growing knowledge of G-NEN pathophysiology and close collaboration between pathologists, gastroenterologists, radiologists, surgeons, and oncologists have enabled a growing trend towards de-escalation and less-invasive treatment paradigms.

Early detection of multiple endocrine neoplasia type 1: A case report

BACKGROUND

Multiple endocrine neoplasias (MENs) are a group of hereditary diseases involving multiple endocrine glands, and their prevalence is low. MEN type 1 (MEN1) has diverse clinical manifestations, mainly involving the parathyroid glands, gastrointestinal tract, pancreas and pituitary gland, making it easy to miss the clinical diagnosis.

CASE SUMMARY

We present the case of a patient in whom MEN1 was detected early. A middle-aged male with recurrent abdominal pain and diarrhea was admitted to the hospital. Blood tests at admission revealed hypercalcemia and hypophosphatemia, and emission computed tomography of the parathyroid glands revealed a hyperfunctioning parathyroid lesion. Gastroscopy findings suggested a duodenal bulge and ulceration. Ultrasound endoscopy revealed a hypoechoic lesion in the duodenal bulb. Further blood tests revealed elevated levels of serum gastrin. Surgery was performed, and pathological analysis of the surgical specimens revealed a parathyroid adenoma after parathyroidectomy and a neuroendocrine tumor after duodenal bulbectomy. The time from onset to the definitive diagnosis of MEN1 was only approximately 1 year.

CONCLUSION

For patients who present with gastrointestinal symptoms accompanied by hypercalcemia and hypophosphatemia, clinicians need to be alert to the possibility of MEN1.

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.

Typical Zollinger-Ellison syndrome-atypical location of gastrinoma and absence of hypergastrinemia: A case report and review of literature

BACKGROUND

Zollinger-Ellison syndrome (ZES) results from hypersecretion of gastrin from pancreatic or duodenal neuroendocrine tumors, commonly referred to as gastrinomas. The high levels of gastrin lead to a typical presentation involving watery diarrhea and multiple ulcers in the duodenum. Here, we have presented the rare case of a patient with ZES and absence of hypergastrinemia as well as an atypical location of gastrinoma.

CASE SUMMARY

A 72-year-old woman presented with the typical clinical manifestations of ZES, including upper abdominal pain, significant watery diarrhea, and acidic liquid vomitus. Surprisingly, however, she did not have an increased level of serum gastrin. In addition, there was no evidence of gastrinoma or any other ulcerogenic tumor. Esophagogastroduodenoscopy was conducted to examine the upper digestive tract. Revised diagnoses were considered, and an individualized treatment plan was developed. The patient responded to antacid medication while experiencing intermittent, recurring bouts of ZES. 18F-AlF-NOTA-octreotide positron emission tomography (18F-OC PET)/computed tomography (CT) helped locate the tumor. Postoperative pathology and immunohistochemistry results suggested that the tumor was a gastrinoma located at an unconventional site.

CONCLUSION

This present case study demonstrates the possibility of ZES-like manifestation in patients with absence of hypergastrinemia. 18F-OC PET/CT is a relatively new imaging technique that can be applied for diagnosing even tiny gastrinomas that are atypical in terms of location.

Esophageal Perforation Unveiling the Diagnosis of Zollinger-Ellison Syndrome

Gastrinomas are the most common neuroendocrine tumors worldwide and cause a clinical syndrome known as Zollinger-Ellison Syndrome (ZES). Increased acid production resulting from elevated gastrin levels contributes to symptoms such as abdominal pain, heartburn, and diarrhea. However, the non-specificity and overlap in the symptoms with idiopathic peptic ulcer disease and gastroesophageal reflux disease (GERD) can lead to delayed diagnosis. In this case, we describe a patient with a past medical history of GERD and a perforated gastric ulcer who continued to experience symptoms of dyspepsia and had a subsequent esophageal perforation, despite H. pylori eradication and high-dose proton pump inhibitor (PPI) therapy. Multiple ulcers were visualized in the first portion of the duodenum, and metastatic lesions were demonstrable in the liver. Serum gastrin level was elevated to 433 pg/mL. Histology of liver biopsy showed a well-differentiated neuroendocrine tumor, supporting the diagnosis of ZES. This article underscores the significance of considering ZES in the differential in cases of refractory gastric hyperacidity and the importance of early diagnosis with serum gastrin testing to prevent complications such as gastric obstruction, perforation, hemorrhage, esophageal strictures, or rupture and to minimize the risk of metastasis. It is noteworthy that while perforations in cases of ZES typically occur in the duodenum, this particular case is atypical as it had involved the stomach. Furthermore, it was associated with esophageal perforation, likely resulting from forceful and prolonged vomiting caused by persistent dyspepsia.

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.

Single-cell transcriptomics uncovers EGFR signaling-mediated gastric progenitor cell differentiation in stomach homeostasis

Defects in gastric progenitor cell differentiation are associated with various gastric disorders, including atrophic gastritis, intestinal metaplasia, and gastric cancer. However, the mechanisms underlying the multilineage differentiation of gastric progenitor cells during healthy homeostasis remain poorly understood. Here, using a single-cell RNA sequencing method, Quartz-Seq2, we analyzed the gene expression dynamics of progenitor cell differentiation toward pit cell, neck cell, and parietal cell lineages in healthy adult mouse corpus tissues. Enrichment analysis of pseudotime-dependent genes and a gastric organoid assay revealed that EGFR-ERK signaling promotes pit cell differentiation, whereas NF-κB signaling maintains gastric progenitor cells in an undifferentiated state. In addition, pharmacological inhibition of EGFR in vivo resulted in a decreased number of pit cells. Although activation of EGFR signaling in gastric progenitor cells has been suggested as one of the major inducers of gastric cancers, our findings unexpectedly identified that EGFR signaling exerts a differentiation-promoting function, not a mitogenic function, in normal gastric homeostasis.

Radiological Features of Zollinger–Ellison Syndrome: A Report of Two Cases

Hypersecretion of gastrin from duodenal or pancreatic gastrinomas results in a rare clinical entity called Zollinger–Ellison syndrome (ZES). It mostly presents with abdominal pain and diarrhea. ZES may be sporadic or occur in association with multiple endocrine neoplasia type 1. Usually, ZES manifests between 20 and 50 years.

We report two cases of patients who presented with abdominal pain, vomiting, watery diarrhea, and significant weight loss.

Nanofiber capsules for minimally invasive sampling of biological specimens from gastrointestinal tract

Accurate and rapid point-of-care tissue and microbiome sampling is critical for early detection of cancers and infectious diseases and often result in effective early intervention and prevention of disease spread. In particular, the low prevalence of Barrett's and gastric premalignancy in the Western world makes population-based endoscopic screening unfeasible and cost-ineffective. Herein, we report a method that may be useful for prescreening the general population in a minimally invasive way using a swallowable, re-expandable, ultra-absorbable, and retrievable nanofiber cuboid and sphere produced by electrospinning, gas-foaming, coating, and crosslinking. The water absorption capacity of the cuboid- and sphere-shaped nanofiber objects is shown ∼6000% and ∼2000% of their dry mass. In contrast, unexpanded semicircular and square nanofiber membranes showed <500% of their dry mass. Moreover, the swallowable sphere and cuboid were able to collect and release more bacteria, viruses, and cells/tissues from solutions as compared with unexpanded scaffolds. In addition to that, an expanded sphere shows higher cell collection capacity from the esophagus inner wall as compared with the unexpanded nanofiber membrane. Taken together, the nanofiber capsules developed in this study could provide a minimally invasive method of collecting biological samples from the duodenal, gastric, esophagus, and oropharyngeal sites, potentially leading to timely and accurate diagnosis of many diseases. STATEMENT OF SIGNIFICANCE: Recently, minimally invasive technologies have gained much attention in tissue engineering and disease diagnosis. In this study, we engineered a swallowable and retrievable electrospun nanofiber capsule serving as collection device to collect specimens from internal organs in a minimally invasive manner. The sample collection device could be an alternative endoscopy to collect the samples from internal organs like jejunum, stomach, esophagus, and oropharynx without any sedation. The newly engineered nanofiber capsule could be used to collect, bacteria, virus, fluids, and cells from the abovementioned internal organs. In addition, the biocompatible and biodegradable nanofiber capsule on a string could exhibit a great sample collection capacity for the primary screening of Barret Esophagus, acid reflux, SARS-COVID-19, Helicobacter pylori, and gastric cancer.

Zollinger Ellison Syndrome Refractory to Medical Therapy in the Setting of Multiple Endocrine Neoplasia Type I

Multiple Endocrine Neoplasia 1 (MEN1) syndrome is a genetic condition arising from a mutation of the MEN1 gene resulting in neuroendocrine tumor formation. Patients with MEN1 are at a higher risk of developing Zollinger-Ellison syndrome (ZES) due to the growth of neuroendocrine tumors called gastrinomas that release gastrin leading to hypersecretion of acid in the stomach resulting in severe ulcerative disease of the upper GI tract. Our case is a 42-year-old female with newly diagnosed MEN1 syndrome, presenting with acute abdominal pain and dyspepsia refractory to medical management including proton pump inhibitors (PPI) and H2 antagonists. ZES was biochemically confirmed with a secretin stimulation test and dotatate positron emission tomography/computed tomography (PET/CT) revealed multiple areas of hyper-metabolic activity within the gastrinoma triangle. However, no discrete masses could be appreciated on endoscopic ultrasound (EUS) or CT imaging that could provide a target for surgical intervention. This case elucidates not only the difficulty of gastrinoma localization in medically refractory ZES but also reinforces the need to screen patients with MEN1 presenting with acute abdominal pain and dyspepsia for ZES.

An update on the diagnosis of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) arise from neuroendocrine cells found throughout the gastrointestinal tract and islet cells of the pancreas. The incidence and prevalence of GEP-NENs have been increasing each year due to higher awareness, improved diagnostic modalities, and increased incidental detection on cross-sectional imaging and endoscopy for cancer screening and other conditions and symptoms. GEP-NENs are a heterogeneous group of tumors and have a wide range in clinical presentation, histopathologic features, and molecular biology. Clinical presentation most commonly depends on whether the GEP-NEN secretes an active hormone. The World Health Organization recently updated the classification of GEP-NENs to introduce a distinction between high-grade neuroendocrine tumors and neuroendocrine carcinomas, which can be identified using histology and molecular studies and are more aggressive with a worse prognosis compared to high-grade neuroendocrine tumors. As our understanding of the biology of GEP-NENs has grown, new and improved diagnostic modalities can be developed and optimized. Here, we discuss clinical features and updates in diagnosis, including histopathological analysis, biomarkers, molecular techniques, and radiology of GEP-NENs. We review established diagnostic tests and discuss promising novel diagnostic tests that are currently in development or require further investigation and validation prior to broad utilization in patient care.

Causes of Exocrine Pancreatic Insufficiency Other Than Chronic Pancreatitis

Exocrine pancreatic insufficiency (EPI), an important cause of maldigestion and malnutrition, results from primary pancreatic disease or is secondary to impaired exocrine pancreatic function. Although chronic pancreatitis is the most common cause of EPI, several additional causes exist. These include pancreatic tumors, pancreatic resection procedures, and cystic fibrosis. Other diseases and conditions, such as diabetes mellitus, celiac disease, inflammatory bowel disease, and advanced patient age, have also been shown to be associated with EPI, but the exact etiology of EPI has not been clearly elucidated in these cases. The causes of EPI can be divided into loss of pancreatic parenchyma, inhibition or inactivation of pancreatic secretion, and postcibal pancreatic asynchrony. Pancreatic enzyme replacement therapy (PERT) is indicated for the conditions described above presenting with clinically clear steatorrhea, weight loss, or symptoms related to maldigestion and malabsorption. This review summarizes the current literature concerning those etiologies of EPI less common than chronic pancreatitis, the pathophysiology of the mechanisms of EPI associated with each diagnosis, and treatment recommendations.

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.

Time to give up traditional methods for the management of gastrointestinal neuroendocrine tumours

Neuroendocrine tumors (NETs) are a rare and heterogeneous disease group and constitute 0.5% of all malignancies. The annual incidence of NETs is increasing worldwide. The reason for the increase in the incidence of NETs is the detection of benign lesions, incidental detection due to the highest use of endoscopic and imaging procedures, and higher recognition rates of pathologists. There have been exciting developments regarding NET biology in recent years. Among these, first of all, somatostatin receptors and downstream pathways in neuroendocrine cells have been found to be important regulatory mechanisms for protein synthesis, hormone secretion, and proliferation. Subsequently, activation of the mammalian target of rapamycin pathway was found to be an important mechanism in angiogenesis and tumor survival and cell metabolism. Finally, the importance of proangiogenic factors (platelet-derived growth factor, vascular endothelial growth factor, fibroblastic growth factor, angiopoietin, and semaphorins) in the progression of NET has been determined. Using the combination of biomarkers and imaging methods allows early evaluation of the appropriateness of treatment and response to treatment.

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.

Neuroendocrine Tumors of the Gastrointestinal Tract and Pancreas

Neuroendocrine neoplasms (NENs) of the gastrointestinal (GI) tract and pancreas are a rare and heterogeneous group of neoplasms characterized by common cellular features as well as unique site-specific traits. GI and pancreatic NENs are much rarer than the more common adenocarcinomas arising at these sites. However, the incidences of GI and pancreatic NENs have increased significantly, particularly in the stomach and common site, followed by rectum, appendix, colon, and stomach. Pancreatic NENs are also uncommon, with fewer than 1 per 100,000, accounting for 1% to 2% of all pancreatic neoplasms.

The Neuroendocrine Neoplasms of the Digestive Tract: Diagnosis, Treatment and Nutrition

Nuroendocrine neoplasms (NENs) are a group of rare neoplasms originating from dispersed neuroendocrine cells, mainly of the digestive and respiratory tract, showing characteristic histology and immunoprofile contributing to classification of NENs. Some NENs have the ability to produce biogenic amines and peptide hormones, which may be associated with clinical syndromes like, e.g., the carcinoid syndrome caused by unmetabolized overproduced serotonin, hypoglycemic syndrome in case of insulinoma, or Zollinger-Ellison syndrome accompanying gastrinoma. Diagnostics for these include ultrasound with endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography/computed tomography (PET/CT). Different nuclear medicine procedures can also be used, like somatostatin analogues scintigraphy (SRS) and 68Ga-Dota-Peptide PET/CT, as well as biochemical methods to determine the level of general neuroendocrine markers, such as chromogranin A (CgA), 5-hydroxyindolacetic acid (5-HIAA), synaptopfysin and cell type-specific peptide hormones, and neurotransmitters like gastrin, insulin, serotonin, and histamine. NENs influence the whole organism by modulating metabolism. The treatment options for neuroendocrine neoplasms include surgery, somatostatin analogue therapy, radionuclide therapy, chemotherapy, molecular targeted therapies, alpha-interferon therapy, and inhibitors of serotonin production. In the case of hypersensitivity to biogenic amines, a diet that limits the main sources of amines should be used. The symptoms are usually connected with histamine, tyramine and putrescine. Exogenic sources of histamine are products that take a long time to mature and ferment. Patients with a genetic insufficiency of the diamine oxidase enzyme (DAO), and those that take medicine belonging to the group of monoamine oxidases (MAO), are particularly susceptible to the negative effects of amines. Diet plays an important role in the initiation, promotion, and progression of cancers. As a result of the illness, the consumption of some nutrients can be reduced, leading to nutritional deficiencies and resulting in malnutrition. Changes in metabolism may lead to cachexia in some patients suffering from NENs. The aim of this narrative review was to advance the knowledge in this area, and to determine possibilities related to dietary support. The authors also paid attention to role of biogenic amines in the treatment of patients with NENs. We can use this information to better understand nutritional issues faced by patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), and to help inform the development of screening tools and clinical practice guidelines.

Atypical Thymic Carcinoid in a Patient with Zollinger-Ellison Syndrome

Atypical thymic carcinoid is an extremely rare tumor with a poor prognosis. In addition to its known association with multiple endocrine neoplasia type 1, its hallmark characteristics include local invasion and early distant metastasis. In this report, we share our experience treating atypical thymic carcinoid in a patient with Zollinger-Ellison syndrome.

Case report: optimal tumor cytoreduction and octreotide with durable disease control in a patient with MEN-1 and Zollinger-Ellison syndrome-over a decade of follow-up

Background

Zollinger-Ellison syndrome (ZES) is a rare condition characterized by hypersecretion of gastrin by gastrinoma tumors leading to severe peptic ulcer disease with potential development of gastric carcinoid tumors. Herein, we report the clinical course of a 68-year-old patient with multiple endocrine neoplasia type 1 (MEN-1) who underwent several surgeries to ultimately undergo optimal tumor cytoreduction of locally advanced gastrinomas and symptomatic gastric carcinoids. The patient was subsequently maintained on octreotide long-acting release (LAR). This case report supports consideration for aggressive tumor cytoreduction and octreotide in similar patients with MEN-1-associated ZES for durable disease control and symptom management.

Case presentation

The patient is a 68-year-old male with multiple endocrine neoplasia type 1 (MEN-1), diagnosed in 1993 after presenting with recurrent renal calculi and hypercalcemia. Soon thereafter, he presented with symptoms and elevated gastrin levels suggestive of ZES prompting abdominal exploration with partial resection of the duodenum to remove gastrinoma tumor nodules. Within 4 years of the operation, he represented with intractable hypergastrinemia despite optimal medical management with peak gastrin levels exceeding 29,000 pg/mL, in 2006. In January 2007, the patient returned to the operating room for resection of regional peripancreatic and perigastric lymph nodes and enucleation of pancreatic body and tail gastrinoma tumors. Although his gastrin level decreased to 5000 pg/mL with resultant improvement of symptoms, in less than 2 years, he developed disease progression with obstructive symptomatology from enlarging gastric carcinoids and rising gastrin levels. In May of 2008, he underwent pancreaticoduodenectomy and near-total gastrectomy. Since June of 2008, the patient shows no demonstrable progression of disease and remains asymptomatic on LAR octreotide (30 mgs). Gastrin levels have been well controlled (range, 100–624 pg/mL; current 114 pg/mL).

Conclusion

Success of this procedure in our case report highlights the potential role for optimal tumor cytoreduction and LAR octreotide to control disease progression in a patient with MEN-I and Zollinger-Ellison syndrome with locally advanced gastrinoma and secondary large gastric carcinoids.

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.

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.

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.

Multiple Endocrine Neoplasia Type 1: A Case Report With Review of Imaging Findings

Background

Multiple endocrine neoplasia type 1 (MEN1) is a rare, autosomal dominant inherited syndrome caused by mutations in the MEN1 tumor suppressor gene. The diagnosis is defined clinically by the presence of 2 or more primary MEN1 tumors (parathyroid, anterior pituitary, and pancreatic islet). We describe the case of a patient who presented with classic history and imaging findings for MEN1.

Case Report

A male in his early thirties with a history of hyperparathyroidism and a transsphenoidal prolactinoma resection presented years later with abdominal symptoms concerning for Zollinger-Ellison syndrome: worsening epigastric abdominal pain, nausea, vomiting, and diarrhea. Contrast-enhanced computed tomography (CT) of the abdomen revealed hyperenhancing pancreatic lesions and duodenal inflammation, suggesting pancreatic neuroendocrine tumor (gastrinoma) with secondary duodenitis. Bilateral indeterminate hypoattenuating adrenal nodules were also seen on contrast-enhanced CT, and follow-up magnetic resonance imaging confirmed benign adrenal adenomas. Furthermore, thyroid ultrasound and sestamibi scintigraphy revealed a parathyroid adenoma. With confirmatory imaging findings, history, and presenting symptoms, the patient was clinically diagnosed with MEN1 syndrome and underwent surgical and medical management.

Conclusion

This case exhibits the classic history with corresponding imaging findings of MEN1 syndrome, including pancreatic neuroendocrine tumors, parathyroid adenoma, and adrenal adenomas. High clinical suspicion for MEN1 should lead to endocrinology evaluation with appropriate laboratory workup and targeted imaging evaluation of the typical endocrine organs as described for this patient.

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.

Introduction and practical approach to exocrine pancreatic insufficiency for the practicing clinician

AIMS

In exocrine pancreatic insufficiency (EPI), the quantity and/or activity of pancreatic digestive enzymes are below the levels required for normal digestion, leading to maldigestion and malabsorption. Diagnosis of EPI is often challenging because the characteristic signs and symptoms overlap with those of other gastrointestinal conditions. Additionally, there is no single convenient, or specific diagnostic test for EPI. The aim of this review is to provide a framework for differential diagnosis of EPI vs other malabsorptive conditions.

METHODS

This is a non-systematic narrative review summarising information pertaining to the aetiology, diagnosis and management of EPI.

RESULTS

Exocrine pancreatic insufficiency may be caused by pancreatic disorders, including chronic pancreatitis, cystic fibrosis, pancreatic resection and pancreatic cancer. EPI may also result from extra-pancreatic conditions, including coeliac disease, Zollinger-Ellison syndrome and gastric surgery. Timely and accurate diagnosis of EPI is important, as delays in treatment prolong maldigestion and malabsorption, with potentially serious consequences for malnutrition, overall health and quality of life. Symptoms of EPI are non-specific; therefore, a high index of clinical suspicion is required to make a correct diagnosis.

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.

Assessing for Multiple Endocrine Neoplasia Type 1 in Patients Evaluated for Zollinger-Ellison Syndrome-Clues to a Safer Diagnostic Process

BACKGROUND

Zollinger-Ellison syndrome is a rare cause of tumoral hypergastrinemia; 1 of 5 patients with this syndrome also has multiple endocrine neoplasia type 1. The diagnosis of this disease is complicated by the widespread use of proton pump inhibitors that can elevate serum gastrin levels, the cornerstone for biochemical diagnosis. Abrupt discontinuation of proton pump inhibitors could lead to adverse outcomes. Clinician awareness of the relationship between Zollinger-Ellison syndrome and multiple endocrine neoplasia type 1 could lead to a safer diagnostic pathway.

METHODS

We conducted a retrospective review of a cohort of patients with multiple endocrine neoplasia type 1.

RESULTS

There were 287 patients with multiple endocrine neoplasia type 1 (73 with gastrinoma) evaluated between 1997 and 2014. Two patients experienced adverse events after proton pump inhibitor therapy was discontinued to re-measure serum gastrin level during the evaluation of severe peptic ulcer disease. In both cases, the diagnosis of multiple endocrine neoplasia type 1 was made after proton pump therapy was discontinued.

CONCLUSION

Abrupt discontinuation of proton pump therapy can lead to adverse outcomes in patients with Zollinger-Ellison syndrome. Clinical assessment for features of multiple endocrine neoplasia type 1 (eg, serum calcium levels, personal and family history of hypercalcemia, pituitary or pancreatic tumors) could identify patients with higher risk for a tumoral source of hypergastrinemia where imaging studies can help support the diagnosis without the potential side effects of abrupt discontinuation of proton pump inhibitor therapy.

A Perplexing Case of Abdominal Pain That Led to the Diagnosis of Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome (ZES) is a rare clinical disorder, characterized by hypersecretion of gastric acid and multiple ulcers distal to the duodenal bulb. This occurs via the release of gastrin by neuroendocrine tumors known as gastrinomas. Patients with ZES present with nonspecific GI symptoms, which often leads to a delay in diagnosis. Our patient is a 55-year-old female with chronic abdominal pain, nausea, and diarrhea. She underwent EGD, EUS, MRCP, CT scans, and cholecystectomy, which did not reveal the cause of her symptoms. Repeat EGD showed a cratered ulcer in the second portion of the duodenum, suspicious for ZES. Serum gastrin was initially only moderately elevated while on PPI therapy, but chromogranin A was also elevated. Repeat gastrin level after stopping PPI therapy was 1639 pg/mL. Somatostatin receptor scintigraphy was obtained, which showed two small lesions in the gastrinoma triangle. She subsequently underwent a Whipple pancreaticoduodenectomy and pathology was positive for four microscopic foci of a neuroendocrine tumor. She reported improvement in her symptoms after surgery. This case highlights the need for increased awareness of ZES in patients with unexplained GI complaints and emphasizes the use of multiple modalities in the diagnosis of ZES.

Gastric Mixing During Food Digestion: Mechanisms and Applications

Gastric mixing is a complex process that is governed by meal properties, such as food buffering capacity, physical properties, and the rate of breakdown as well as physiological factors, such as the rate of gastric secretions, gastric emptying, and gastric motility. Gastric mixing processes have been studied through the use of experimental and computational methods. Gastric mixing impacts the intragastric pH distribution and residence time in the stomach for ingested materials. Development of a fundamental understanding of the advective and diffusion processes and their roles in gastric mixing will be important in furthering our understanding of food breakdown, microbial survival, and drug dissolution during gastric digestion.

[Management of gastrinoma]

Gastrinoma is a very rare tumor leading to gastrin hypersecretion and characterised by Zollinger-Ellisson syndrome (ZES) i.e. severe gastric and duodenal ulceration and profuse diarrhea. This disease can be sporadic or familial within a multiple endocrine neoplasia type 1 (MEN-1) syndrome. Diagnosis is based on hypergastrinemia/hypercholrhydria. Tumors are usually located in the duodeno-pancreas. Preoperative tumor location by CT, echoendoscopy and fibroscopy is not always possible because of the small size of the lesion that are frequently multiple. The aim of gastrinoma treatment is 1/to control the hormonal hypersecretion 2/to remove the neoplasm when it is possible. Surgery is the only chance to cure. Gastrinoma is a slow-growing tumor, and overall survival is good with a median survival above 10years and a 5-year survival above 80 % in surgically resected patients. Recurrence is frequent, a biochemical recurrence is observed in 65 % of cases and morphological recurrence in 40 % of patients at 2years. Metastases are associated with a dismal prognosis.

Signs and genetics of rare cancer syndromes with gastroenterological features

Although the genetic bases of most hereditary cancer syndromes are known, and genetic tests are available for them, the incidence of the most rare of these syndromes is likely underestimated, partially because the clinical expression is neither fully understood nor easily diagnosed due to the variable and complex expressivity. The clinical features of a small pool of rare cancer syndromes include gastroenterological signs, though not necessarily tumors, that could require the intervention of a gastroenterologist during any of the phases of the clinical management. Herein we will attempt to spread the knowledge on these rare syndromes by summarizing the phenotype and genetic basis, and revising the peculiar gastroenterological signs whose underlying role in these rare hereditary cancer syndromes is often neglected. Close collaboration between geneticists and gastroenterologists could facilitate both the early identification of patients or relatives at-risk and the planning of multidisciplinary and tailored management of these subjects.

Comparison study of gastrinomas between gastric and non-gastric origins

BACKGROUND

Gastrinomas are one of the neuroendocrine tumors with potential distant metastasis. Most gastrinomas are originated from pancreas and duodenum, but those of gastric origin have been much less reported. The aim of the study is to compare gastrinomas of gastric and non-gastric origins.

METHODS

Four hundred twenty-four patients with neuroendocrine tumor by histological proof in Chang Gung Memorial Hospital, Linkou branch in the past 10 years were included. A total of 109 (25.7 %) cases were identified of upper gastrointestinal origins, of which 20 (18.3 %) were proven gastrinomas. The clinical characteristics were collected and analyzed retrospectively.

RESULTS

In our study, 21 tumors of the 20 cases were identified by pathologic proof, 11 (55 %) had resection or endoscopic mucosa resection, 9 of gastric origins, 9 of duodenal origins, 2 of pancreatic origins, and 1 of hepatic origins. One case had multiple lesions. Patients with gastric gastrinomas had older age, higher levels of gastrin, seemingly smaller tumor size (p = 0.024, 0.030, and 0.065, respectively), and usually lower grade in differentiation (p = 0.035). Though gastric gastrinomas had a high recurrent rate (80 %), the lymph node and liver involvement was less common. Gastrinomas with liver involvement/metastasis had a high mortality rate where 80 % died of liver dysfunction.

CONCLUSIONS

Gastrinomas originating from stomach had higher gastrin level and lower tumor grading and presented at older age. The long-term outcome was probably better than non-gastric origin because of lower grading and less lymph node and liver involvement.

[Surgery for gastrinoma: Short and long-term results]

INTRODUCTION

Zollinger-Ellison syndrome (Z-E) is characterized by gastrin-secreting tumors, responsible for causing refractory and recurrent peptic ulcers in the gastrointestinal tract. The optimal approach and the extension of tumor resection remains the subject of debate.

METHODS

During the period February 2005 and February 2014, 6 patients with Z-E underwent surgery, 4 men and 2 women with a median age 46.8 years (22-61). Two patients were affected with multiple endocrine neoplasia type-1 (MEN-1). Fasting gastrin levels greater than 200pg/ml (NV: <100) was diagnostic. Radiologic imaging to localize the lesion included octreoscan 6/6, computer tomography (CT) 6/6, and endoscopic ultrasonography (EUS) 1/6.

RESULTS

The octreoscan was positive in 5 patients. The CT localized the tumor in the pancreas in 2 patients, in the duodenum in 3 patients (1 confirmed by EUS) and between the common bile duct and vena cava in one patient. The laparoscopic approach was used in 4 patients, 2 patients converted to open surgery. The following surgical techniques were performed: 2 pylorus-preserving pancreatico-duodenectomy (PPPD), one spleen-preserving distal pancreatectomy, one duodenal nodular resection, 1 segmental duodenectomy and one extrapancreatic nodular resection. Pathological studies showed lymph nodes metástasis in 2 patients with pancreatic gastrinomas, and in one patient with duodenal gastrinoma. The median follow-up was 76,83 months (5-108) and all patients presented normal fasting gastrin levels.

CONCLUSIONS

Surgery may offer a cure in patients with Z-E. The laparoscopic approach remains limited to selected cases.

Gastric secretion

PURPOSE OF REVIEW

This review summarizes the past year's literature regarding the neural, paracrine, hormonal, and intracellular regulation of gastric acid secretion.

RECENT FINDINGS

Gastric acid facilitates the digestion of protein as well as the absorption of iron, calcium, vitamin B12, and certain medications. High gastric acidity, in combination with pepsin and lipase, kills ingested microorganisms and may play a role in preventing bacterial overgrowth, enteric infection, and possibly spontaneous bacterial peritonitis, community-acquired pneumonia, and infection with Mycobacterium tuberculosis. Stimulants of acid secretion include histamine, gastrin, acetylcholine, and ghrelin. Inhibitors include somatostatin, gastric inhibitory polypeptide, calcitonin gene-related peptide, and adrenomedullin. Helicobacter pylori stimulates or inhibits depending upon the time course of infection and the area of the stomach predominantly infected. Proteins implicated in H-K-ATPase membrane trafficking include myosin IIB, F-actin, ezrin, and Rab GTPases.

SUMMARY

Our understanding of the regulation of gastric acid secretion continues to advance. Such knowledge is crucial for the management of acid-peptic disorders and the development of novel medications, such as cholecystokinin-2 receptor antagonists.