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.

All you need to know about gastrinoma today | Gastrinoma and Zollinger-Ellison syndrome: A thorough update.

Zollinger-Ellison syndrome (ZES) is a distinct syndrome characterized by hyperchlorhydria-induced peptic ulcer disease and chronic diarrhea. It is the result of a gastrin-excess state caused by a duodenal or pancreatic neuroendocrine tumor referred to as gastrinoma. This gastrin-secreting neuroendocrine tumor is usually sporadic in nature, or part of multiple endocrine neoplasia type 1 syndrome. The high rate of malignancy associated with gastrinomas substantiates the need for early diagnosis. In order to diagnose ZES with laboratory tests, patients under antacid medication are required to stay off proton pump inhibitors for at least one week and H2 receptor antagonists for 48 h. Fasting serum gastrin level measurement serves as an initial and fundamental diagnostic test, boasting a sensitivity of 99%. Gastrinoma patients will present with a gastrin level greater than 100 pg/mL, while a serum gastrin level higher than 1000 pg/mL, in the presence of gastric pH <2, is considered diagnostic. Since more common causes of hypergastrinemia exist in the setting of hypochlorhydria, ruling those out should precede ZES consideration. Such causes include atrophic gastritis, Helicobacter pylori (H. pylori)-associated pangastritis, renal failure, vagotomy, gastric outlet obstruction and retained antrum syndrome. The secretin stimulation test and the calcium gluconate injection test represent classic adjuvant diagnostic techniques, while alternative approaches are currently being introduced and evaluated. Specifically, the secretin stimulation test aids in differentiating ZES cases from other hypergastrinemic states. Its principle is based on secretin stimulation of gastrinoma cells to secrete gastrin, while inhibiting normal G cells. The rapid intravenous infusion of 4 µg/kg secretin over 1 min is followed by gastrin level evaluation at specific intervals post-infusion. Localization of the primary tumor and its metastases is the next diagnostic step when gastrinoma-associated ZES is either suspected or biochemically confirmed. Endoscopic ultrasound has showcased sensitivity as high as 83% for pancreatic gastrinomas and is considered the primary modality in such cases, although its tumor detection rates are substantially lower in duodenal lesions. Gallium-68 radiotracers, especially DOTATOC with positron emission tomography, are currently setting the standard in tumor localization, enhancing traditional imaging techniques and showcasing high sensitivity and specificity. Although gastrinomas have been reported in various anatomic locations, the vast majority arise in a specific site named the "gastrinoma triangle", involving parts of the duodenum, pancreas and extra-hepatic biliary system. Proton pump inhibitors serve as the cornerstone of symptomatic ZES treatment. Surgery is routinely performed in localized sporadic ZES, irrespective of imaging results. ZES in multiple endocrine neoplasia type 1 requires work-up for evaluation and treatment of hyperparathyroidism, while surgery might be an option for selected cases. In cases of advanced and metastatic disease, there is a variety of potential treatments, ranging for somatostatin analogs to chemotherapeutic drugs, liver-directed therapies and liver transplantation, while neither hepatic metastases, nor locally invasive disease necessarily preclude surgical management. This article thoroughly and critically reviews available literature and provides an extensive and multidimensional overview of ZES, along with current controversies regarding management of this disease.

[Primary lymph node gastrinoma]. / Gastrinoma primario de ganglio linfático.

Gastrinomas are neuroendocrine tumors usually located in the duodenum and pancreas, in the context of a Multiple Endocrine Neoplasm and forming a Zollinger-Ellison syndrome. The location of this type of lymph node tumor is extremely unusual and its early diagnosis constitutes a real challenge to be able to establish an adequate treatment and manage the complications that these entail. We present the case of a 64-year-old male patient with a lymph node gastrinoma and whose surgical removal resulted in the immediate remission of the patient's symptoms.

Gastroduodenal neuroendocrine neoplasms including gastrinoma - update of the diagnostic and therapeutic guidelines (recommended by the Polish Network of Neuroendocrine Tumours) [Nowotwory neuroendokrynne zoladka i dwunastnicy z uwzglednieniem gastrinoma - uaktualnione zasady postepowania (rekomendowane przez Polska Siec Guzów Neuroendokrynnych)].

After another meeting of experts of the Polish Network of Neuroendocrine Tumours, updated recommendations for the management of patients with gastric and duodenal neuroendocrine neoplasms, including gastrinoma, have been issued. As before, the epidemiology, pathogenesis and clinical symptoms of these neoplasms have been discussed, as well as the principles of diagnostic procedures, including biochemical and histopathological diagnostics and tumour localisation, highlighting the changes introduced in the recommendations. Updated principles of therapeutic management have also been presented, including endoscopic and surgical treatment, and the options of pharmacological and radioisotope treatment. The importance of monitoring patients with gastric and duodenal NENs, including gastrinoma, has also been emphasised.

A case of refractory esophageal stricture due to occult gastrinoma of the duodenum.

Gastrinoma may cause refractory esophageal stricture due to gastro-esophageal reflux disease (GERD), but imaging technologies have limited power in its diagnosis. A 74-year-old female with a history of peptic ulcers suffered from repeated epigastralgia, and she visited a local hospital. An esophago-gastro-duodenoscopy (EGD) demonstrated severe reflux esophagitis and multiple peptic ulcers. Blood examination revealed a high value of fasting serum gastrin. Multi-detector computed tomography showed a hypervascular and tiny nodule in duodenal bulb, although other imaging technologies did not. Short-term medication with a proton pump inhibitor or potassium-competitive acid blocker was intermittently provided, but dysphagia was repeatedly worsened, and she was referred to our division. Serum hypergastrinemia was retained, and EGD reexamination depicted esophageal stricture, treated by multiple sessions of endoscopic balloon dilatation. Primary tumor was not identified by the morphological imaging technologies, but a selective arterial secretagogue injection test suggested its existence in the duodenum or pancreatic head. Pancreaticoduodenectomy was performed, and histological study identified 2 mm-sized microgastrinoma buried in Brunner`s glands on the posterior wall of the duodenum bulb. We reported a case with difficulty in diagnosis of the smallest sporadic gastrinoma of the duodenum, which might cause refractory GERD-associated stricture.

Combined surgical and medical management of a cat with gastrinoma.

Gastrinomas are gastrin-secreting pancreatic tumours rarely diagnosed in cats. A 12-year-old female spayed cat was presented for vomiting, anorexia and weight loss. Physical exam revealed lethargy, dehydration and thin body condition. Pertinent laboratory abnormalities included a mild mature neutrophilia and borderline hypoalbuminaemia. Imaging of the abdomen revealed a mass-like change to the proximal duodenum. Exploratory laparotomy was performed, and the duodenal mass along with a 3-mm pancreatic nodule was removed. Immunohistochemical staining of the pancreatic nodule confirmed a gastrinoma. Following surgery, treatment was initiated with omeprazole and toceranib. Toceranib was discontinued after 8 weeks due to hyporexia. The patient was continued on omeprazole long term and has survived more than 35 months since diagnosis. Little information regarding treatment and prognosis for feline gastrinomas is available. In this case report, long-term survival was achieved with a combined surgical and medical approach using omeprazole and toceranib.

Secretin Stimulation Test and Early Diagnosis of Gastrinoma in MEN1 Syndrome: Survey on the MEN1 Florentine Database.

CONTEXT: Multiple endocrine neoplasia type 1 (MEN1) is a rare inherited endocrine cancer syndrome. Multiple gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) affect 30% to 80% of MEN1 patients, with the most common functioning GEP-NET being gastrinoma. Biochemical identification of hypergastrinemia may help to recognize the presence of gastrinomas before they are detectable by instrumental screening, enabling early diagnosis and start of therapy, preferably before tumor progression and metastases occurrence. OBJECTIVE: Evaluate the effectiveness of secretin stimulation test to precociously diagnose the presence of gastrin-secreting tumors. DESIGN: Results of secretin stimulation tests, performed between 1991 and February 2020, were retrospectively analyzed, as aggregate, in a cohort of MEN1 patients with GEP-NETs. SETTING: Data were extracted from the MEN1 Florentine database. PATIENTS: The study included 72 MEN1 patients with GEP-NETs who underwent a secretin stimulation test for the evaluation of gastrin secretion. OUTCOMES: A positive secretin stimulation test was assumed with a difference between basal fasting serum gastrin (FSG) and the maximum stimulated value of gastrin over 120 pg/mL. RESULTS: The secretin stimulation test showed a secretin-induced hypergastrinemia in 27.8% (20/72) of patients with GEP-NETs, and a positive test in 18 cases. The test allowed the identification of a positively stimulated hypergastrinemia in 75.0% (3/4) of patients who presented a basal FSG within the normal range. CONCLUSIONS: Diagnosis of gastrinoma is complex, difficult, and controversial. Results of this study confirm that a positive secretin stimulation test allows early diagnosis of gastrinomas, even in the presence of borderline or normal levels of nonstimulated FSG.

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.

Analytical and Clinical Performance of a Liquid Chromatography-Tandem Mass Spectrometry Method for Measuring Gastrin Subtypes G34 and G17 in Serum.

BACKGROUND: Two major forms of gastrin, gastrin-17 (G17) and gastrin-34 (G34), exist in blood. However, conventional immunoassay methods can only quantify total gastrin or G17 alone. Here, we aimed to establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify G17 and G34 simultaneously. METHODS: Serum samples were prepared by anion-exchange solid-phase extraction. The analytical performance of the LC-MS/MS method was validated and the method was compared to chemiluminescence immunoassay (CLIA) and radioimmunoassay (RIA). The G17 and G34 concentrations in 245 serum samples from healthy controls, individuals with gastrinoma, and individuals with other diseases were analyzed. RESULTS: The total runtime of the LC-MS/MS method was 6 min. No substantial matrix effect was observed with internal standard correction. The intraassay coefficients of variation (CVs) for G17 and G34 were 4.0%-14.2% and 4.4%-10.4%, respectively, and total CVs were 5.2%-14.1% and 4.6%-12.4%, respectively. The correlation coefficient between LC-MS/MS and CLIA was 0.87, and between LC-MS/MS and RIA was 0.84. The G17+G34 concentrations for 87.5% of individuals with gastrinoma were higher than the 95th percentile of healthy controls (18.1 pg/mL), whereas the concentrations for individuals with other diseases and gastrinoma overlapped. Based on the Youden indices calculated for G17+G34, G34, and G17, the most specific biomarker was G17 (96.9% clinical specificity at 209.8 pg/mL) for gastrinoma. CONCLUSIONS: This method should aid in the diagnosis of diseases associated with increased gastrin concentrations.

A germline c.1546dupC MEN1 mutation in an MEN1 family: A case report.

RATIONALE: Multiple endocrine neoplasia type 1 (MEN1) is a rare tumor syndrome with an autosomal dominant inheritance, and genetic testing for MEN1 gene is important for both affected individuals and their relatives. We present a 2-person family affected by a germline c.1546dupC MEN1 mutation, and one of them had a full-spectrum of MEN-related endocrine tumors. PATIENT CONCERNS: A female patient aged 32 years presented with jejunal ulcer perforation due to gastrinoma. DIAGNOSES: We conducted genetic analysis and extensive biochemical/radiological evaluation for detecting other endocrine tumors. Multiple pancreatic neuroendocrine tumors (NETs), prolactinoma and primary hyperparathyroidism were diagnosed, and a frame-shift mutation, NM_130799.1:c.1546dupC (p.Arg516Profs∗15), was detected. One daughter of the proband, aged 12 years, had the same mutation for MEN1. INTERVENTION: She underwent pancreatic surgery for pancreatic NETs and total parathyroidectomy for primary hyperparathyroidism. OUTCOMES: After pancreatic surgery, long-term symptoms of epigastric soreness, acid belching, sweating, and palpitation in fasting were improved. Hypercalcemia was improved after parathyroidectomy and she was supplemented with oral calcium and vitamin D. Her daughter showed normal biochemical surveillance until 15 years of age. LESSONS: We report 2 people in a family affected by MEN1 with the heterozygous germline c.1546dupC mutation, a variant that should be surveilled for early development of full-blown MEN1-associated endocrine tumors.

Primary lymph node gastrinoma: a case report and review of the literature.

BACKGROUND: Gastrinoma is a rare form of neuroendocrine neoplasm. The presence of a primary lymph node localization of gastrinoma is a much debated and controversial topic in the literature, as regards whether these cases represent metastatic disease from an as yet unidentified primary tumor, or the de novo occurrence of a gastrinoma in a lymph node. CASE PRESENTATION: We report the case of a 24-year-old male with intense epigastric pain treated at the beginning with high dose proton pump inhibitors. Further workup with CT and subsequent laparotomy revealed a single peripancreatic lymph node. Histological examination highlighted a well-differentiated neuroendocrine tumor. CONCLUSION: This case underlines that the primitive lymph node gastrinoma is a distinct nosological entity with a precise location in the context of rare neuroendocrine tumors that should be considered when specific symptoms are associated with the identification of isolated lymph nodes, after excluding any possible primitive locations of neoplastic localization.

Diagnostic accuracy of selective arterial calcium injection test for localization of gastrinoma.

The appropriate localization of gastrinoma is still difficult. We aimed to evaluate the diagnostic accuracy of selective arterial calcium injection (SACI) for localization of gastrinomas including multiple lesions. This retrospective study included ten patients with surgically proven gastrinomas (gastrinoma group) and six patients without any findings suggesting Zollinger-Ellison syndrome (non-gastrinoma group). For SACI, calcium gluconate was injected into the arteries supplying pancreas, duodenum, and liver. Blood samples from the hepatic vein were obtained before and 30, 60, and 120 seconds after each injection. The results were considered positive when the increase in serum immunoreactive gastrin (IRG) levels within 60 seconds of calcium gluconate injection were more than 80 pg/mL and more than 20% from baseline. We evaluated the efficacy of SACI by comparing the SACI responses with definitive locations diagnosed by clinical and histopathological findings. In the gastrinoma group, false-positive responses were confirmed in seven of the ten patients. False-negative response was observed in one of the feeding arteries of one patient with gastrinomas in multiple locations. Conversely, the greatest increase in serum gastrin levels from baseline at 30 seconds indicated the true-positive responses in all patients with gastrinomas. In the non-gastrinoma group, calcium gluconate injection into gastroduodenal artery evoked positive responses in five of the six patients. In conclusion, our data suggest the strongest gastrin response evoked by SACI indicates the definitive location in patients with gastrinomas. In contrast, SACI could not accurately locate multiple gastrin-secreting lesions due to poor specificity.

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.

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.

Duodenal neuroendocrine neoplasms: a still poorly recognized clinical entity.

BACKGROUND: Duodenal neuroendocrine neoplasms (dNENs) are rare tumors, which usually show good prognosis. The optimal management of these tumors is still far from being clearly understood because of their rarity and the poor level of knowledge about their natural history. Herein, we have reviewed the literature on dNENs to collect and analyze the current data on epidemiology, diagnosis and management of these rare tumors. METHODS: Bibliographical searches were performed in PubMed, using the following keywords: duodenal neuroendocrine neoplasm; duodenum; gastrinoma; diagnosis; therapy; guidelines. We searched for all relevant articles published over the last 15 years. Non-English language papers were excluded. RESULTS: We reviewed the pertinent articles about dNENs. Upper gastrointestinal endoscopy with biopsy is the cornerstone of the dNENs diagnostic process. Endoscopic ultrasound with fine-needle aspiration/biopsy should be performed in order to locally stage the disease and in all cases of non-diagnostic endoscopy. Endoscopic or complete surgical removal of the primary lesion is the recommended treatment and is generally achievable for the majority of the patients. A less aggressive approach may be suggested for well-differentiated low-stage tumors. After NEN removal, patients should be closely followed-up especially during the first 3 years by endoscopic examination, imaging tests and CgA measurements. CONCLUSIONS: The multi-disciplinary approach and the preservation of the quality of life of the patients play a key role in the therapeutic process for dNENs. Further studies are needed to better define standardized guidelines specific to dNENs, including optimal management approaches and follow-up intervals.

Ectopic Cushing syndrome: Report of 9 cases. / Síndrome de Cushing ectópico: descripción de 9 casos.

INTRODUCTION: Ectopic Cushing's syndrome (ECS) is a rare condition caused by ACTH secretion by extrapituitary tumors. Its low frequency makes it difficult to acquire experience in its management. The aim of this study was to describe patients with ECS seen at the endocrinology department of a tertiary hospital over 15 years. METHODS: This was a retrospective study of the clinical, biochemical and radiographic data, treatment, and course of patients with ECS seen from 2000 to 2015. RESULTS: Nine patients (6 of them female) with a mean age of 47 years were included in the study. The clinical syndrome developed in less than 3 months in all cases but one, and most patients also had edema, hyperpigmentation and/or hypokalemia. Mean urinary free cortisol and ACTH levels were 2,840µg/24h and 204pg/mL respectively. The ectopic origin was confirmed by a combination of dynamic non-invasive tests and radiographic studies in most cases. The tumor responsible could be identified in 8 cases, and 7 patients had metastatic dissemination. Primary treatment was surgery in one patient, surgery combined with systemic therapy in 3, and chemotherapy in the other 3 patients. Bilateral adrenalectomy was required in 4 patients to control hypercortisolism. After a mean follow-up of 40 months, 3 patients died, 5 were still alive, and one had been lost to follow-up. CONCLUSIONS: Our study confirms that ECS covers a wide spectrum of tumors of different aggressiveness and nature. The ectopic origin of Cushing's syndrome can usually, be suspected and confirmed in most cases without the need for invasive tests. Control of both hypercortisolism and the tumor requires multiple treatment modalities, and multidisciplinary management is recommended.