Gastric neuroendocrine neoplasms: A review

The use of precision radiotherapy for the management of cancer-related pain in the abdomen

PURPOSE OF REVIEW

Abdominal pain due to cancer is a significant and debilitating symptom for cancer patients, which is commonly undertreated. Radiotherapy (RT) for the management of abdominal cancer pain is underused, with limited awareness of its benefit. This review presents a discussion on current precision RT options for the management of cancer pain in the abdomen.

RECENT FINDINGS

Precision RT focuses on delivering targeted and effective radiation doses while minimizing damage to surrounding healthy tissues. In patients with primary or secondary liver cancer, RT has been shown to significantly improve liver related cancer pain in the majority of patients. Also, symptom sequelae of tumour thrombus may be relieved with the use of palliative RT. Similarly, single dose, high precision stereotactic RT to the celiac plexus has been shown to significantly improve pain in patients with pancreatic cancer. Pain response for adrenal metastases has been less commonly investigated, but small series suggest that stereotactic body RT may reduce or alleviate pain.

SUMMARY

RT is an effective option for the treatment of abdominal cancer pain. RT should be considered within the multidisciplinary treatment armamentarium, and may be successfully integrated, alone or in conjunction with other treatment modalities, in abdominal cancer-related pain.

Neuroendocrine tumors in the stomach: An epidemiological analysis of Belgian Cancer Registry data 2010-2019

The prevalence of gastric NEN is estimated worldwide at 8.9% of all gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) and only 0.3%-1% of all gastric neoplasms, but is rising in the last decades. The aim of this project was to map the epidemiology of gastric neuroendocrine neoplasm (gNEN) in Belgium. This is a population-wide retrospective cohort study over 10 years (2010-2019), based on data from the Belgian Cancer Registry. A total of 641 patients were included; 605 patients with gNEN and 36 with MiNEN. The AAIR of gNEN was 0.67 per 100,000 person-years, increasing over the years and with a slight female predominance (55.4%). Neuroendocrine carcinoma (NEC) accounted for 15.7% (N = 95), with an AAIR of 0.11 per 100,000 person-years. The other 510 patients were diagnosed with gNET: G1 NET was most prevalent (54.3%) followed by G2 (32.5%) and G3 NET (3.5%). Concerning the clinical classification (type) of gNET, a diagnosis of type 1 tumors was presumed in 67.6%, type 3 tumors in 17.1% and type 2 tumors in 0.6% of patients. In only 3.8% of patients, the clinical classification was explicitly stated in the pathology report. Stage IV tumors were diagnosed in 13.4% (N = 81). A favorable evolution in pathology reporting is seen. Some variables-for example, clinical classification of gNET-were heavily underreported, stressing the importance of registries integrating clinical and pathological information.

A case of early-stage type 3 gastric neuroendocrine tumor in the upper body of the stomach: is endoscopic resection feasible?

Although gastric neuroendocrine tumors (NETs) are uncommon compared with gastric carcinomas, the incidence of NETs has been recently increasing. Gastric NETs are classified into three subgroups, and among these, gastrin-independent sporadic type 3 gastric NETs have a poor prognosis because of frequent lymph node or distant metastasis. We experienced a case of an early-stage type 3 gastric NET associated with lymphovascular and submucosal invasion. In a 54 year-old woman, esophagogastroduodenoscopy performed during a health screening identified an elevated lesion of the upper body of the stomach. The results of immunohistochemical analyses of endoscopic biopsy specimens obtained from the lesion were positive for chromogranin A and synaptophysin, indicating an NET. Because the patient's serum gastrin level was normal and she had no predisposing conditions for NET development, the tumor was diagnosed as a type 3 gastric NET. The patient underwent local resection of the tumor and regional lymph node dissection. The resected specimen indicated a diagnosis of type 3 gastric NET with invasion into the submucosa and lymphatic duct. This is an extremely rare case of an early-stage type 3 gastric NET. Our discussion provides insight into the pathogenesis and development of these tumors and the appropriate therapeutic strategy.

Laparoscopic total gastrectomy for multiple type І gastric neuroendocrine tumours: a case report

Background. The gastric neuroendocrine tumours (G-NETs), arising from neuroendocrine cells within the stomach. Type I lesions are associated with chronic atrophic gastritis (CAG). Multiple G-NETs are rare. Purpose – of our report is to describe a rare case of multiple Type-I G-NETs. Material and methods. During routine gastroscopy in a 44-year-old female with history of CAG and anaemia, multiple (15–20) polyps of size 2–9 mm were found. Multiple biopsies were obtained. Histopathological examination with haematoxylin and eosin staining described these lesions as undifferentiated cancer. Repeated gastroscopy was done. The three biggest polyps (5–9 mm) were removed by snare polypectomy. Repeated histopathological examination was specific for G-NET. The neoplasm presented Ki-67 proliferation index of < 3%; Cytokeratin 18, Chromogranin A, Synaptophysin, INSM1 were positive in neoplasm cells. Laparoscopic total gastrectomy was done. The operative time was 255 min, and the blood loss was 50 ml. Histopathological examination of a surgical specimen revealed multiple, Grade 1 G-NET (fig. 1–3). All lesions are limited to the mucosa and submucosa of the stomach, the longest size of the largest tumour lesion is 5 mm, what corresponds to pT1(m). No signs of lymphovascular or perineural invasion were found (L0 V0 Pn0). 18 regional lymph nodes were examined, no metastases were detected (0/18, pN0). Edges of resections of the esophagus and duodenum without signs of tumour growth (R0). Outside of tumours, there were signs of chronic inflammation of the stomach mucosa, with intestinal metaplasia and mixed glandular atrophy, there are also foci of nodular hyperplasia of neuroendocrine cells. Conclusion. We reported a rare case of multiple type-I G-NETs (pT1N0M0) with pernicious anaemia due to autoimmune CAG. Laparoscopic total gastrectomy is a method of choice in treatment of such patients.

Gastric Neuroendocrine Carcinoma Presenting as Ascites in a Young Female

Although neuroendocrine tumors (NETs) can occur in any organ, the majority of them occur in the gastrointestinal (GI) tract. We present the case of a 27-year-old female who presented with ascites. She underwent an ascitic fluid analysis, an esophagogastroduodenoscopy (EGDscopy) with biopsies, and a positron emission tomography (PET) scan, all of which culminated in a diagnosis of a poorly differentiated gastric NET (small cell type) with peritoneal metastasis. She was treated with cisplatin and etoposide. Depending on the differentiation and grade, NETs can manifest in a variety of ways. Definitive diagnosis requires histopathological examination and immunostaining. For smaller well-differentiated NETs, management is either endoscopic or surgical resection. For neuroendocrine carcinomas with metastasis, chemotherapy and symptomatic management are advised. This case report highlights the rare presentation of a neuroendocrine carcinoma as well as discusses its diagnostic approach and possible treatment options.

Gastric Polyps Detected Incidentally during Gastroscopy and Follow-Up Results

(1) Background: We aimed to identify the possible relationship between various diseases of the upper digestive system and colon polyps by analyzing patients with gastric polyps and evaluating the cancers and diseases accompanying the polyps. (2) Methods: Each patient's age; gender; polyp type and size; presence of Helicobacter pylori (H. pylori), atrophic gastritis, and intestinal metaplasia; status of whether cancer developed during follow-up; status of whether a colonoscopy was performed or not; and colon pathologies detected during colonoscopy were analyzed retrospectively using hospital records. (3) Results: Between the study dates, 19,214 esophagogastroduodenoscopies were performed in the endoscopy unit of our hospital. Gastric polyps were detected in 178 (0.9%) patients. No significant relationship was found between the gastric polyp size and the occurrence of gastric cancer or gastrointestinal system malignancy (p > 0.05). A colonoscopy was performed in 86 of the 178 patients who underwent gastroscopy. The frequency of polyp detection during colonoscopy was statistically significantly higher in patients with gastric polyps than in patients without gastric polyps (p < 0.001). (4) Conclusions: New prospective studies are needed regarding the relationship between gastric polyps and gastrointestinal system diseases. Going forward, a colonoscopy will be required in gastric polyp patients, especially with FGP.

Neuroendocrine Neoplasia: From Pathophysiology to Novel Therapeutic Approaches

Neuroendocrine neoplasia (NEN) represents a sensational field of modern medicine; immense progress in emerging biochemical, molecular, endocrine, immunohistochemical, and serum tumour markers of disease, respectively, which are part of early diagnosis, genetic testing, and multidisciplinary approaches [...].

Management of type 1 gastric neuroendocrine tumors: an 11-year retrospective single-center study

BACKGROUND

Type 1 gastric neuroendocrine tumors (NETs) are relatively rare to the extent that some physicians have little experience in diagnosing and treating them. The purpose of this study was to increase the understanding of the disease by analyzing and summarizing the management and prognoses of patients with type 1 gastric NETs at our center.

METHODS

The data of 229 patients (59.4% female) with type 1 gastric NETs who were treated at our center during 2011-2022 were retrospectively analyzed.

RESULTS

The average patient age was 50.5 ± 10.8 years. Multiple tumors affected 72.5% of the patients; 66.4% of the tumors were < 1 cm, 69.4% were NET G1, and 2.2% were stage III-IV. A total of 76.9% of the patients had received endoscopic management, 60.7% had received traditional Chinese medicine treatment, 10.5% received somatostatin analogues treatment, and 6.6% underwent surgical resection. Seventy patients (41.2%) experienced the first recurrence after a median follow-up of 31 months (range: 2-122 months), and the median recurrence-free time was 43 months. The 1-, 2-, and 3-year cumulative recurrence-free survival rates were 71.8%, 56.8%, and 50.3%, respectively. During a median follow-up of 39 months (range: 2-132 months), one patient had bilateral pulmonary metastasis, and no disease-related deaths were observed.

CONCLUSION

Type 1 gastric NETs have a high recurrence rate and a long disease course, underscoring the importance of long-term and comprehensive management.

Application of machine learning algorithms to predict lymph node metastasis in gastric neuroendocrine neoplasms

Background

Neuroendocrine neoplasms (NENs) are tumors that originate from secretory cells of the diffuse endocrine system and typically produce bioactive amines or peptide hormones. This paper describes the development and validation of a predictive model of the risk of lymph node metastasis among gastric NEN patients based on machine learning platform.

Methods

In this investigation, data from 1256 patients were used, of whom 119 patients from the First Affiliated Hospital of Soochow University in China and 1137 cases from the surveillance epidemiology and end results (SEER) database were combined. Six machine learning algorithms, including the logistic regression model (LR), random forest (RF), decision tree (DT), Naive Bayes (NB), support vector machine (SVM), and k-nearest neighbor algorithm (KNN), were used to build the predictive model. The performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity.

Results

Among the 1256 patients with gastric NENs, 276 patients (21.97 %) developed lymph node metastasis. T stage, tumor size, degree of differentiation, and sex were predictive factors of lymph node metastasis. The RF model achieved the best predictive performance among the six machine learning models, with an AUC, accuracy, sensitivity, and specificity of 0.81, 0.78, 0.76, and 0.82, respectively.

Conclusion

The RF model provided the best prediction and can help physicians determine the lymph node metastasis risk of gastric NEN patients to formulate individualized medical strategies.

Gastroenteropancreatic Neuroendocrine Tumors-Current Status and Advances in Diagnostic Imaging

Gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN) is a heterogeneous and complex group of tumors that are often difficult to classify due to their heterogeneity and varying locations. As standard radiological methods, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET/CT) are available for both localization and staging of NEN. Nuclear medical imaging methods with somatostatin analogs are of great importance since radioactively labeled receptor ligands make tumors visible with high sensitivity. CT and MRI have high detection rates for GEP-NEN and have been further improved by developments such as diffusion-weighted imaging. However, nuclear medical imaging methods are superior in detection, especially in gastrointestinal NEN. It is important for radiologists to be familiar with NEN, as it can occur ubiquitously in the abdomen and should be identified as such. Since GEP-NEN is predominantly hypervascularized, a biphasic examination technique is mandatory for contrast-enhanced cross-sectional imaging. PET/CT with somatostatin analogs should be used as the subsequent method.

Detection of Neuroendocrine Tumours by Enteroscopy: A Case Report

We present the case of a 62-year-old patient who developed melenas and in whom conventional endoscopic tests could not detect any bleeding lesion. In our case, capsule endoscopy and enteroscopy were the pivotal elements in establishing the diagnosis of a neuroendocrine tumour with an atypical location. As a result, it was possible to surgically remove the lesions at an early stage of the malignancy without metastatic disease and without the need for adjuvant therapy. Our case demonstrates the need for these new techniques in tumours of atypical location and aggressive course. Otherwise, this malignancy may be underdiagnosed until an advanced stage.

Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

BACKGROUND

The incidence of type I gastric neuroendocrine neoplasms (gNENs) has increased significantly over the past 50 years. Although autoimmune gastritis (AIG) increases the likelihood of developing gNENs, the exact incidence and prevalence of this association remain unclear.

AIM

To evaluate the incidence and prevalence of type I gNENs in a cohort of patients with a histological diagnosis of AIG.

METHODS

Patients with a histological diagnosis of AIG were enrolled between October 2020 and May 2022. Circulating levels of CgA and gastrin were assessed at enrollment. Included patients underwent regular endoscopic follow-up to detect gastric neoplastic lesions, enterochromaffin-like (ECL) cell hyperplasia, and the development of gNEN.

RESULTS

We included 176 patients [142 women (80.7%), median age 64 years, interquartile range (IQR) 53-71 years] diagnosed with AIG between January 1990 and June 2022. At enrollment. One hundred and sixteen patients (65.9%) had ECL hyperplasia, of whom, 29.5% had simple/linear, 30.7% had micronodular, and 5.7% had macronodular type. The median follow-up time was 5 (3-7.5) years. After 1032 person-years, 33 patients developed a total of 50 type I gNENs, with an incidence rate of 0.057 person-years, corresponding to an annual cumulative incidence of 5.7%. Circulating CgA levels did not significantly differ between AIG patients who developed gNENs and those who did not. Conversely, gastrin levels were significantly higher in AIG patients who developed gNENs [median 992 pg/mL IQR = 449-1500 vs 688 pg/mL IQR = 423-1200, P = 0.03]. Calculated gastrin sensitivity and specificity were 90.9% and 1.4%, respectively, with an overall diagnostic accuracy of 30% and a calculated area under the gastrin receiver operating characteristic curve (AUROC or AUC) of 0.53.

CONCLUSION

Type I gNENs are a significant complication in AIG. Gastrin's low diagnostic accuracy prevents it from serving as a marker for early diagnosis. Effective strategies for early detection and treatment are needed.

Gastric Neuroendocrine Tumors (g-NETs): A Systematic Review of the Management and Outcomes of Type 3 g-NETs

PURPOSE

to collect data from real-life experiences of the management of type 3 g-NETs and identify possible prognostic factors that may impact the decision-making process.

METHODS

We performed a systematic review of the literature on type 3 g-NET management using the PubMed, MEDLINE, and Embase databases. We included cohort studies, case series, and case reports written in the English language.

RESULTS

We selected 31 out of 556 articles from between 2001 and 2022. In 2 out of the 31 studies, a 10 mm and 20 mm cut-off size were respectively associated with a higher risk of gastric wall infiltration and/or lymph node and distant metastasis at diagnosis. The selected studies reported a higher risk of lymph node or distant metastasis at diagnosis in the case of muscularis propria infiltration or beyond, irrespective of the dimensions or grading. From these findings, size, grading, and gastric wall infiltration seem to be the most relevant factors in management staff making choices and prognoses of type 3 g-NET patients. We produced a hypothetical flowchart for a standardized approach to these rare diseases.

CONCLUSION

Further prospective analyses are needed to validate the prognostic impact of the use of size, grading, and gastric wall infiltration as prognostic factors in the management of type 3 g-NETs.

Neuroendocrine Neoplasms: Epidemiology, Diagnosis, and Management

Neuroendocrine tumors have variety of biological and clinical characteristics. The classification of neuroendocrine neoplasm has evolved, and the newest 2019 World Health Organization classification outlines a well-differentiated high-grade G3 subtype, recognizing its differences from the poorly differentiated neuroendocrine carcinoma. ⁶⁸Ga-DOTAT PET has largely replaced somatostatin scintigraphy as the diagnostic workup choice for NENs. NETest, a multi-analyte liquid biopsy, is a promising recent development in the biochemical diagnosis. Management includes wait and watch approach, surgical resection, somatostatin analogs, ¹⁷⁷Lu DOTATATE therapy, chemotherapy, radiotherapy or immunotherapy combinations. Further clinical trials are necessary for determining the appropriate sequencing.

Factors Predicting Type I Gastric Neuroendocrine Neoplasia Recurrence: A Single-Center Study

Type I gastric neuroendocrine neoplasms (gNENs) are associated with atrophic gastritis and have a high recurrence rate, which means frequent endoscopies are required. The objective of this study was to identify factors predicting the local recurrence of type I gNENs. The clinical course and the pathological and biochemical data of patients with type I gNENs treated at Bnai Zion Medical Center between 2006 and 2022 were analyzed retrospectively. Twenty-seven type I gNENs were evaluated. The follow-up period was 41 months (range: 11–288 months). Recurrence of the tumor occurred in 13/27 (48%) patients after 35 months (median (M), interquartile range (IQR): 21–67.5). Serum gastrin levels were significantly higher in patients with recurrent disease versus patients with non-recurrent disease (788 vs. 394 ng/L; p = 0.047), while the Ki-67 index was significantly lower in patients with recurrent disease versus patients with non-recurrent disease (1% vs. 3.5%; p = 0.035). Tumor size, mitotic count, and serum chromogranin A levels did not correlate with recurrence. The present study emphasizes the role of gastrin in the pathogenesis of gNEN recurrence and highlights the debate regarding the ability of the Ki-67 index to predict the clinical course of this disease.

The Complex Histopathological and Immunohistochemical Spectrum of Neuroendocrine Tumors-An Overview of the Latest Classifications

Neuroendocrine neoplasms (NENs) originate from the neuroendocrine cell system, which may either take the shape of organoid cell aggregations or be composed of dispersed cells across various organs. Therefore, these tumors are heterogenous regarding the site of origin, functional status, degree of aggressiveness, and prognosis. When treating patients with neuroendocrine tumors, one of the most significant challenges for physicians is determining the correct tumor grade and thus classifying patients into risk categories. Over the years, the classification of these tumors has changed significantly, often causing confusion due to clinical, molecular, and immunohistochemical variability. This review aims to outline the latest NENs classifications regardless of their site of origin. Thus, an overview of the key histopathological and immunohistochemical characteristics of NENs could pave the way to validate possible predictive and prognostic markers and also guide the therapeutic conduct.

Inflammation Related to Obesity in the Etiopathogenesis of Gastroenteropancreatic Neuroendocrine Neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare neoplasms, which, due to their heterogeneous nature, non-specific symptoms, and lack of specific tumor markers pose many diagnostic and clinical challenges. In recent years, the effectiveness of GEP-NEN diagnosis has increased, which is probably associated with the greater availability of diagnostic tests and the cooperation of many experienced specialists in various scientific disciplines. In addition to the possible genetic etiology, the cause of GEP-NET development is not fully understood. Inflammation and obesity are known risks that contribute to the development of many diseases. Chronic inflammation accompanying obesity affects the hormonal balance and cell proliferation and causes the impairment of the immune system function, leading to neoplastic transformation. This review explores the role of inflammation and obesity in GEP-NETs. The exact mechanisms inducing tumor growth are unknown; however, the profile of inflammatory factors released in the GEP-NET tumor microenvironment is responsible for the progression or inhibition of tumor growth. Both the excess of adipose tissue and the impaired function of the immune system affect not only the initiation of cancer but also reduce the comfort and lifetime of patients.

Type-1 Grade 2 Multi-Focal Gastric Neuroendocrine Tumors Secondary to Chronic Autoimmune Gastritis

Background

Chronic autoimmune gastritis (CAG) refers to chronic atrophic gastritis due to autoimmunity. Loss of gastric glands in CAG results in hypergastrinemia and achlorhydria leading to Vitamin B12 deficiency and hyperplasia of G cells and enterochromaffin-like (ECL) cells. Vitamin B12 deficiency could cause pernicious anemia and subacute combined degeneration, while G cells and ECL cells hyperplasia might develop gastric neuroendocrine tumor (G-NET).

Case Presentation

A 35-year-old Chinese female presented with multi-focal type-1 Grade 2 (G2) NETs with a 14-year history of pernicious anemia and subacute combined degeneration.

Conclusion

Here, we report a rare case of a Chinese patient presenting G-NET combined with pernicious anemia and subacute combined degeneration, which are secondary to chronic autoimmune gastritis. This case also illustrates the importance of routine gastroscopy in patients with Vitamin B12 deficiency.

Gastrik polipler: 10 yıllık endoskopik işlemin retrospektif analizi

Objective: Gastric polyps are gastric mucosal protrusions that are usually asymptomatic and detected incidentally during upper gastrointestinal system endoscopy. In this study, the incidence, location and general characteristics of gastric polyps were evaluated. Materials and methods: Upper gastrointestinal system endoscopies performed in a tertiary hospital for a period of ten years were evaluated retrospectively. Demographic characteristics of the patients, gastroscopy indications, morphological and histological characteristics of polyps were recorded. Results: Gastric polyps were found in 347 (1.4%) of a total of 25230 gastroscopy patients. The mean age of the patients was 61.04 ± 15.05 and 64.3% were female. 124 (35.7%) of the patients were male and 223 (64.3%) were female. The most common endoscopic indication (74.1%) of the patients with polyps was dyspepsia. Most of the polyps (55.3%) were smaller than 5 mm and the most common site was the antrum. Hyperplastic polyp (44.4%) was detected the most. 42.9% of the patients with polyps were positive for Helicobacter pylori. In addition, 58% of adenomatous polyps were accompanied by dysplasia. Conclusion: Hyperplastic polyps were the most common polyp type in our population. Full excision of polyps over 5 mm (especially adenomatous polyps) is recommended instead of biopsy, as they may contain dysplasia foci. In addition, it was thought that taking polyps smaller than 5 mm into endoscopic follow-up without excision was more cost-effective.

Current updates and future directions in diagnosis and management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms are a heterogenous group of rare neoplasms that are increasingly being discovered, often incidentally, throughout the gastrointestinal tract with varying degrees of activity and malignant potential. Confusing nomenclature has added to the complexity of managing these lesions. The term carcinoid tumor and embryonic classification have been replaced with gastroenteropancreatic neuroendocrine neoplasm, which includes gastrointestinal neuroendocrine and pancreatic neuroendocrine neoplasms. A comprehensive multidisciplinary approach is important for clinicians to diagnose, stage and manage these lesions. While histological diagnosis is the gold standard, recent advancements in endoscopy, conventional imaging, functional imaging, and serum biomarkers complement histology for tailoring specific treatment options. In light of developing technology, our review sets out to characterize diagnostic and therapeutic advancements for managing gastroenteropancreatic neuroendocrine tumors, including innovations in radiolabeled peptide imaging, circulating biomarkers, and endoscopic treatment approaches adapted to different locations throughout the gastrointestinal system.

Gastric neuroendocrine neoplasms and precursor lesions: Case reports and literature review

RATIONALE

Gastric neuroendocrine neoplasms (g-NENs) represent a distinctive group of gastric tumors, stratified into different prognostic categories according to different histological characteristics, put forth in the 2018 World Health Organization classification system. The clinical presentations, as well as pathological features, represent important data in establishing the type of the tumor, in estimating the tumor behavior, and in selecting the best therapeutic strategy. In our case series we presented different clinical scenarios that may be encountered in practice regarding gastric NENs. We performed a literature review and discussed diagnostic strategy, current classification system, precursor lesions, and therapeutic options in g-NENs.

PATIENT CONCERNS

The first patient was a 41-year-old female with weight loss, persistent dyspeptic complaints and a history of pernicious anemia. In the second clinical case a 61-year-old man was admitted with heartburn, abdominal pain, diarrhea and mild iron deficiency anemia. The third patient was a 56-year-old male with a history of neoplasia, admitted for weight loss, dyspeptic complaints, and liver metastases.

DIAGNOSIS

All the 3 patients underwent upper endoscopy with targeted biopsies. Histopathological and laboratory evaluation, together with imagistic evaluation (abdominal ultrasound, endoscopic ultrasound, and magnetic resonance imaging) allowed the distinction between 3 different types of gastric tumors: type 1 enterochromaffin-like-cell G1 NET, type 2 enterochromaffin-like-cell G2 NET, and type 3 G2 NET with liver metastases.

INTERVENTIONS

Endoscopic polypectomy of the largest lesion was performed in patient with type 1 g-NET and autoimmune chronic atrophic gastritis, followed by regular endoscopic surveillance with biopsies. In type 2 g-NET associated with pancreatic gastrinoma, pancreaticoduodenectomy with total gastrectomy were performed. In type 3 g-NET, detected in metastatic stage, oncologic therapy was performed.

OUTCOMES

The patients follow-up was selected according to tumor behavior, from regular endoscopic surveillance to oncology follow-up. The prognosis was good in case 1, whilst poorer outcomes were associated with more aggressive tumors in case 2 and case 3.

LESSONS

g-NENs are rare tumors with distinct clinical and histological features. Our case series emphasized the role of close collaboration between clinician and pathologist, as well as the importance of a detailed pathology report.