An Organoid Biobank of Neuroendocrine Neoplasms Enables Genotype-Phenotype Mapping.

Gastroenteropancreatic (GEP) neuroendocrine neoplasm (NEN) that consists of neuroendocrine tumor and neuroendocrine carcinoma (NEC) is a lethal but under-investigated disease owing to its rarity. To fill the scarcity of clinically relevant models of GEP-NEN, we here established 25 lines of NEN organoids and performed their comprehensive molecular characterization. GEP-NEN organoids recapitulated pathohistological and functional phenotypes of the original tumors. Whole-genome sequencing revealed frequent genetic alterations in TP53 and RB1 in GEP-NECs, and characteristic chromosome-wide loss of heterozygosity in GEP-NENs. Transcriptome analysis identified molecular subtypes that are distinguished by the expression of distinct transcription factors. GEP-NEN organoids gained independence from the stem cell niche irrespective of genetic mutations. Compound knockout of TP53 and RB1, together with overexpression of key transcription factors, conferred on the normal colonic epithelium phenotypes that are compatible with GEP-NEN biology. Altogether, our study not only provides genetic understanding of GEP-NEN, but also connects its genetics and biological phenotypes.

Spatial profiling reveals tissue-specific neuro-immune interactions in gastroenteropancreatic neuroendocrine tumors.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are heterogeneous malignancies that arise from complex cellular interactions within the tissue microenvironment. Here, we sought to decipher tumor-derived signals from the surrounding microenvironment by applying digital spatial profiling (DSP) to hormone-secreting and non-functional GEP-NETs. By combining this approach with in vitro studies of human-derived organoids, we demonstrated the convergence of cell autonomous immune and pro-inflammatory proteins that suggests their role in neuroendocrine differentiation and tumorigenesis. DSP was used to evaluate the expression of 40 neural- and immune-related proteins in surgically resected duodenal and pancreatic NETs (n = 20) primarily consisting of gastrinomas (18/20). A total of 279 regions of interest were examined between tumors, adjacent normal and abnormal-appearing epithelium, and the surrounding stroma. The results were stratified by tissue type and multiple endocrine neoplasia I (MEN1) status, whereas protein expression was validated by immunohistochemistry (IHC). A tumor immune cell autonomous inflammatory signature was further evaluated by IHC and RNAscope, while functional pro-inflammatory signaling was confirmed using patient-derived duodenal organoids. Gastrin-secreting and non-functional pancreatic NETs showed a higher abundance of immune cell markers and immune infiltrate compared with duodenal gastrinomas. Compared with non-MEN1 tumors, MEN1 gastrinomas and preneoplastic lesions showed strong immune exclusion and upregulated expression of neuropathological proteins. Despite a paucity of immune cells, duodenal gastrinomas expressed the pro-inflammatory and pro-neural factor IL-17B. Treatment of human duodenal organoids with IL-17B activated NF-κB and STAT3 signaling and induced the expression of neuroendocrine markers. In conclusion, multiplexed spatial protein analysis identified tissue-specific neuro-immune signatures in GEP-NETs. Duodenal gastrinomas are characterized by an immunologically cold microenvironment that permits cellular reprogramming and neoplastic transformation of the preneoplastic epithelium. Moreover, duodenal gastrinomas cell autonomously express immune and pro-inflammatory factors, including tumor-derived IL-17B, that stimulate the neuroendocrine phenotype. © 2024 The Pathological Society of Great Britain and Ireland.

Management of Gastric Neuroendocrine Tumors: A Review.

Gastric neuroendocrine tumors (G-NET) are rare tumors arising from enterochromaffin-like cells of the gastric mucosa. They belong to a larger group called gastroenteropancreatic neuroendocrine tumors and are classified as low, intermediate, or high-grade tumors based on their proliferative indices. They are further categorized into three subtypes based on their morphologic characteristics, pathogenesis, and behavior. Types 1 and 2 tumors are characterized by elevated serum gastrin and are usually multifocal. They typically occur in the setting of atrophic gastritis or MEN1/Zollinger Ellison syndrome, respectively. Type 2 tumors are associated with the most symptoms, such as abdominal pain and diarrhea. Type 3 tumors are associated with normal serum gastrin, are usually solitary, and occur sporadically. This type has the most aggressive phenotype and metastatic potential. Treatment and prognosis for G-NET is dependent on their type, size, and stage. Type 1 has the best prognosis, and Type 3 has the worst. This review discusses the presentation, workup, and surgical management of these tumors.

The cckOMA syndrome and its relation to the Zollinger-Ellison syndrome: a diagnostic challenge.

OBJECTIVE: Among patients with enteropancreatic neuroendocrine tumor syndromes only one case with a cholecystokinin (CCK) secreting tumor has been reported. She had significant hyperCCKemia leading to a specific syndrome of severe diarrheas, weight loss, repeated duodenal ulcers and a permanently contracted gallbladder with gallstones. There are, however, reasons to believe that further CCKomas exist, for instance among Zollinger-Ellison patients with normal plasma gastrin concentrations. The present review is a call to gastroenterologists for awareness of such CCKoma patients. METHOD: After a short case report, the normal endocrine and oncological biology of CCK is described. Subsequently, the CCKoma symptoms are discussed with particular reference to the partly overlapping symptoms of the Zollinger-Ellison syndrome. In this context, the diagnostic use of truly specific CCK and gastrin assays are emphasized. The discussion also entails the problem of access to accurate CCK measurements. CONCLUSION: Obviously, the clinical awareness about the CCKoma syndrome is limited. Moreover, it is also likely that the knowledge about the necessary specificity demands of diagnostic gastrin and CCK assays have obscured proper diagnosis of the CCKoma syndromes in man.

Pancreatic masses in children: a single-center experience over two decades.

Pancreatic masses are extremely rare in pediatric patients, with limited data available. This lack of data makes the diagnosis and management of these tumors in children extremely challenging. Therefore, we aimed to describe the presentations, clinical course, and outcomes of children with pancreatic tumors at our center. A retrospective analysis was performed of all pediatric patients diagnosed with pancreatic masses between 2003 and 2022 in an academic freestanding children's hospital. Data including demographics, clinical presentation, workup, management, and subsequent morbidity and mortality were collected and aggregated. Furthermore, we reviewed cases of pancreatic tumor resections in the National Surgical Quality Improvement Program - Pediatric (NSQIP-P) database to identify common adverse outcomes and measures for quality improvement. In total, 17 patients were identified at our institution. Diagnoses included solid pseudopapillary (n = 9), gastrinoma (n = 1), rhabdomyosarcoma (n = 2), pancreatoblastoma (n = 2), and insulinoma (n = 1). Two patients did not have a histopathologic diagnosis and were excluded from subsequent analysis. Overall, 12 patients underwent surgical intervention, with the most common procedures being pancreaticoduodenectomy and distal pancreatectomy, and all 12 were known to be alive at last contact. There were 3 deaths, all due to complications related to metastatic disease. Furthermore, 30-day postoperative outcomes in the NSQIP-P dataset for pancreatic surgeries in pediatric patients are excellent, with negligible morbidity and no mortalities after the index surgery. CONCLUSIONS: Children with pancreatic tumors amenable to surgical resection appear to have adequate long-term survival. Short-term outcomes at diagnosis are excellent and mainly appear to be influenced by the presence of metastatic disease at initial presentation. WHAT IS KNOWN: • Pancreatic masses are a rare entity in children with limited data on their presentation, management and surgical outcomes. • Solid Pseudopapillary tumors are one of the most common pancreatic tumors in children with a fair prognosis after surgical intervention. WHAT IS NEW: • Surgical management of pediatric patients with pancreatic tumors is safe and effective in patients who do not have aggressive tumor types or metastatic disease. • Our case series provides a notable cohort of these pancreatic tumors with insight into the presentation, management and outcomes of five of these tumor types.

Middle-segment preserving pancreatectomy: a literature review and case report.

PURPOSE: Middle segment-preserving pancreatectomy (MSPP) is a relatively new parenchymal-sparing surgery that has been introduced as an alternative to total pancreatectomy (TP) for multicentric benign and borderline pancreatic diseases. To date, only 36 cases have been reported in English. METHODS: We reviewed 22 published articles on MSPP and reported an additional case. RESULTS: Our patient was a 49-year-old Japanese man diagnosed with Zollinger-Elison syndrome (ZES) caused by duodenal and pancreatic gastrinoma associated with multiple endocrine neoplasia syndrome type 1. We avoided TP and chose MSPP as the operative technique due to his relatively young age. The patient developed a grade B postoperative pancreatic fistula (POPF), which improved with conservative treatment. He was discharged without further treatment. To date, no tumor has recurred, and pancreatic function seems to be maintained. According to a literature review, the morbidity rate of MSPP is as high as 54%, mainly due to the high incidence of POPF (32%). In contrast, there was no perioperative mortality, and postoperative pancreatic function was comparable to that after conventional pancreatectomy. CONCLUSIONS: Despite the high incidence of POPF, MSPP appears to be safe, with low perioperative mortality and good postoperative pancreatic sufficiency.

Management of Functional Pancreatic Neuroendocrine Neoplasms.

OPINION STATEMENT: Functional pancreatic neuroendocrine neoplasms (pNENs) are rare and heterogeneous diseases in terms of both clinical and pathological aspects. These tumors secrete hormones or peptides, which may cause a wide variety of symptoms related to a clinical syndrome. The management of functional pNENs is still challenging for clinicians due to the need to control both tumor growth and specific symptoms. Surgery remains the cornerstone in the management of local disease because it can definitively cure the patient. However, when the disease is not resectable, a broad spectrum of therapeutic options, including locoregional therapy, somatostatin analogs (SSAs), targeted therapies, peptide-receptor radionuclide therapy (PRRT), and chemotherapy, are available. The present review summarizes the main key issues regarding the clinical management of these tumors, providing a specific highlight on their therapeutic approach.

Sporadic and MEN1-related gastrinoma and Zollinger-Ellison syndrome: differences in clinical characteristics and survival outcomes.

PURPOSE: Gastrinoma with Zollinger-Ellison syndrome (ZES) may occur sporadically (Sp) or as part of the inherited syndrome of multiple endocrine neoplasia 1 (MEN-1). Data comparing Sp and MEN-1/ZES are scanty. We aimed to identify and compare their clinical features. METHODS: Consecutive patients with ZES were evaluated between 1992 and 2020 among a monocentric Italian patient cohort. RESULTS: Of 76 MEN-1 patients, 41 had gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN), 18 of whom had ZES; of 320 Sp-GEP-NEN, 19 had Sp-ZES. MEN-1/ZES patients were younger (p = 0.035) and the primary MEN-1/ZES gastrinoma was smaller than Sp-ZES (p = 0.030). Liver metastases occurred in both groups, but only Sp-ZES developed extrahepatic metastases. 13 Sp-ZES and 8 MEN-1/ZES underwent surgery. 8 Sp-ZES and 7 MEN-1/ZES received somatostatin analogs (SSAs). Median overall survival (OS) was higher in MEN-1/ZES than in Sp-ZES (310 vs 168 months, p = 0.034). At univariate-logistic regression, age at diagnosis (p = 0.01, OR = 1.1), G3 grading (p = 0.003, OR = 21.3), Sp-ZES (p = 0.02, OR = 0.3) and presence of extrahepatic metastases (p = 0.001, OR = 7.2) showed a significant association with OS. At multivariate-COX-analysis, none of the variables resulted significantly related to OS. At univariate-logistic regression, age (p = 0.04, OR = 1.0), size (p = 0.039, OR = 1.0), G3 grade (p = 0.008, OR = 14.6) and extrahepatic metastases (p = 0.005, OR = 4.6) were independently associated with progression-free survival (PFS). In multivariate-COX-analysis, only extrahepatic metastases (p = 0.05, OR = 3.4) showed a significant association with PFS. Among SSAs-treated patients, MEN-1/ZES showed better PFS (p = 0.0227). After surgery, the median PFS was 126 and 96 months in MEN-1 and Sp, respectively. CONCLUSION: MEN-1/ZES patients generally show better OS and PFS than Sp-ZES as well as better SSAs response.

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.

[Gastroenteropancreatic neuroendocrine tumors : (GEP-NENs)]. / Neuroendokrine Neoplasien des Gastrointestinaltrakts : (GEP-NENs).

The entity of NENs represent a highly heterogenous group of malignancies that require a multidisciplinary approach during the treatment of patients. The following article aims to provide a concise overview of the current state of the art in diagnostics and therapy. One specific feature of G1/G2 NENs is that the indication for surgery is given even in metastatic settings. Specific details regarding the treatment of its various different subgroups need to be gathered from available guidelines or current clinical studies. The field of nuclear medicine offers promising options for diagnostics and therapy which needs further investigation.

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.

Total gastrectomy for severe proton pump inhibitor-induced hypomagnesemia in a MEN1/Zollinger Ellison syndrome patient.

We report here the first case of life-threatening hypomagnesemia in a Zollinger-Ellison syndrome patient with multiple endocrine neoplasia type 1 (MEN1) syndrome. The severe symptomatic hypomagnesemia proved to be due to proton pump inhibitors (PPIs), but withdrawal of PPIs led to early severe peptic complications despite a substitution by histamine H2-receptor antagonist therapy. Simultaneous management of life-threatening hypomagnesemia, severe gastric acid hypersecretion and MEN1-associated gastrinomas was complex. A total gastrectomy was performed in order to definitely preclude the use of PPIs in this frail patient who was not eligible for curative pancreatoduodenal resection.

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.

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.

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.

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.

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.

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.

The Pancreatic Endocrine Tumors - Experience of First Surgical Clinic Iasi.

Pancreatic neuroendocrine tumors (PNETs) are rare and characterized by widely variable clinical presentation and often challenging surgical management. Methods: Retrospective study conducted during the last 15 years at the First Surgical Clinic of the Iasi St Spiridon University Hospital, and which included all the patients diagnosed with pancreatic endocrine tumors by immunohistochemistry. Results: There were 26 cases diagnosed with PNET. The male/female ratios was 7/19 and mean age 41.93 +- 2.48 years (range 20-79 years). Of the PNET cases 13 were insulinomas, 5 gastrinomas, 2 gastrinomas associated with other endocrine neoplasms (Wermer syndrome), 5 non-functional endocrine pancreatic tumors and 1 ACTHoma. Clinical manifestations depended on tumor type: hypoglycemia and Whipple triad for insulinoma, Zollinger Ellison syndrome and complicated peptic ulcer (hemorrhage, perforation) for gastrinoma, Cushing syndrome for ACTHoma. Biological diagnosis included biological markers (e.g. insulin, gastrin and cortisol). Tumor site and size at diagnosis were determined by ultrasound, CT-scan, angiography, PETscan, octreoscan and intraoperative ultrasound. Surgical procedures for PNET insulinomas were: tumor resection - 6 cases; left splenopancreatectomy - 3 cases; left spleen-preserving pancreatectomy - 2 cases; pancreaticoduodenectomy - 2 cases. We also present 4 cases of gastrinoma with multiple ulcers and multiple surgical interventions for hemorrhage and perforation with peritonitis. The two patients with Wermer syndrome also had ulcers complicated with hemorrhage and peritonitis and parathyroid adenoma. Nonfunctional pancreatic endocrine tumors were diagnosed in 5 women of which in 3 the tumors were located in the pancreatic tail (in which splenopancreatectomy and left pancreatectomy with spleen preservation were performed) and in 2 in the pancreatic head (in which pancreaticoduodenectomy and Beger type operation were performed). Conclusions: Knowledge of clinical signs of secreting tumors and exploring the patients are of crucial importance for management of PNETs. Immunohistochemistry is mandatory for confirming the diagnosis and assessing the proliferation and biological behavior of the tumor, thus facilitating the administration of specific therapy. Aggressive surgical treatment is indicated, even in advanced stages.