Endoscopic mucosal resection in the management of gastric carcinoid tumors

Endoscopic features of gastric neuroendocrine tumors

OBJECTIVES

The endoscopic features of gastric neuroendocrine tumors (G-NETs) remain unclarified. The present study investigated the endoscopic features of G-NETs in relation to the clinicopathological findings.

METHODS

This retrospective study analyzed consecutive patients with G-NETs who received endoscopic or surgical treatment between January 2005 and December 2023. The endoscopic and clinicopathological findings of the lesions were analyzed to provide diagnostic information.

RESULTS

Among 29 patients, the characteristic endoscopic findings of G-NETs on white-light images were reddish color (66%), dilated vessels (83%), submucosal tumor-like marginal elevation (59%), and central depression (48%). The gross appearance of G-NETs was classified into two macroscopic subtypes: reddish polypoid lesions (n = 17) and submucosal tumor-like lesions (n = 9). Magnifying narrow-band imaging endoscopy revealed an absent microsurface pattern plus an irregular microvascular pattern in all cases of reddish polypoid lesions with central depressions (100%, 9/9). The findings of a reddish polypoid lesion and an absent microsurface pattern plus an irregular microvascular pattern corresponded to the subepithelial NET component close to the non-neoplastic surface epithelium. Additionally, reddish polypoid lesions were significantly more frequent in type 1 G-NETs than in type 3 G-NETs (80% vs. 11%, p < 0.001), while submucosal tumor-like lesions were significantly more frequent in type 3 G-NETs than in type 1 G-NETs (78% vs. 10%, p < 0.001).

CONCLUSIONS

These endoscopic features should increase the index of suspicion and help clinicians to correctly diagnose G-NETs through the pathological examination of biopsy specimens.

Endoscopic versus surgical resection of duodenal neuroendocrine neoplasms between 10 and 20 mm: A multi-centered retrospective cohort study

INTRODUCTION

Recommendations for resection technique of duodenal neuroendocrine neoplasms (D-NEN) with a size between 10 and 20 mm are lacking. The primary aim was to compare overall survival (OS) and progression-free survival (PFS) after endoscopic resection (ER) with surgical resection (SR). The secondary aim was to assess the incidence and clinical variables correlated with OS.

METHODS

Data of patients with D-NENs between 2008 and 2018 were extracted from the Netherlands Cancer Registry and the Dutch Nationwide Pathology Databank.

RESULTS

A total of 259 patients were identified, of which 138 were included: 98 (68 %) underwent ER and 44 patients (32 %) underwent SR. Of these, 38 patients had D-NENs sized between 10 and 20 mm. ER Patients were more frequently male and had a lower T-stage and tumour size than SR patients (all P < 0.05). Positive resection margins were observed more frequently after ER compared to SR (71 % vs 15 %, P < 0.005). No patients with tumours between 10 and 20 mm died after ER or SR (median follow-up 71.8 vs. 52.0 months). PFS rates were not significantly different after ER compared to SR (P = 0.672). Recurrence rates were 13 % for ER and 7 % for SR (P = 0.604).

CONCLUSION

Between 2008 and 2018, the incidence increased from 0.06 to 0.11 per 100,000 patients per year. OS after ER or SR did not differ for D-NEN between 10 and 20 mm. Recurrence and PFS rates were not significantly different. These results suggest that D-NENs sized between 10 and 20 mm could potentially be treated first with ER. Future studies are needed to confirm this hypothesis.

Risk factors for positive resection margins after endoscopic resection for gastrointestinal neuroendocrine tumors

BACKGROUND

In recent years, the incidence of gastrointestinal neuroendocrine tumors (GI-NETs) has remarkably increased due to the widespread use of screening gastrointestinal endoscopy. Currently, the most common treatments are surgery and endoscopic resection. Compared to surgery, endoscopic resection possesses a higher risk of resection margin residues for the treatment of GI-NETs.

METHODS

A total of 315 patients who underwent surgery or endoscopic resection for GI-NETs were included. We analyzed their resection modality (surgery, ESD, EMR), margin status, Preoperative marking and Prognosis.

RESULTS

Among 315 patients included, 175 cases underwent endoscopic resection and 140 cases underwent surgical treatment. A total of 43 (43/175, 24.57%) and 10 (10/140, 7.14%) patients exhibited positive resection margins after endoscopic resection and surgery, respectively. Multivariate regression analysis suggested that no preoperative marking and endoscopic treatment methods were risk factors for resection margin residues. Among the patients with positive margin residues after endoscopic resection, 5 patients underwent the radical surgical resection and 1 patient underwent additional ESD resection. The remaining 37 patients had no recurrence during a median follow-up of 36 months.

CONCLUSIONS

Compared with surgery, endoscopic therapy has a higher margin residual rate. During endoscopic resection, preoperative marking may reduce the rate of lateral margin residues, and endoscopic submucosal dissection may be preferred than endoscopic mucosal resection. Periodical follow-up may be an alternative method for patients with positive margin residues after endoscopic resection.

Clinical experience sharing on gastric microneuroendocrine tumors: A case report

BACKGROUND

The majority of gastric neuroendocrine tumors (G-NENs) are present in various lesions under endoscopy, and they can be polypoid uplifts, submucosal tumors or papules, erosions, and ulcers. The lesions are mostly confined to the mucosal or submucosal layer, usually less than 2 cm, and exclusively localized to the gastric body or fundus. In type 1 G-NENs, about 22% of cases have no visible lesions under an endoscope, and such lesions can only be detected via biopsies (microcarcinoids).

CASE SUMMARY

A 67-year-old female patient with appetite loss for more than half a year and personal history of hyperthyroidism was admitted to our hospital. After admission, a random multi-point biopsy was performed on the gastric body, fundus, angle, and antrum through gastroscopy. Pathological examination showed chronic severe atrophic gastritis in the fundus and body of the stomach. The small curvature of the gastric body, the anterior wall of the gastric body, and the posterior wall of the gastric body displayed proliferation of intestinal chromaffin cells. The curvature of the gastric body showed neuroendocrine tumor G1 (carcinoid), while the antrum and angle of the stomach showed mild atrophic gastritis with mild intestinal metaplasia. Immunohistochemical examination showed that the greater curvature of the gastric body was Syn (+), CgA (+), and Ki-67 (+, approximately 1%), which is consistent with neuroendocrine tumors (grade 1). Regular gastroscopy and biopsy should be performed every one to two years to monitor G-NENs.

CONCLUSION

In the case under study, the patient did not have any visible raised lesions under a gastroscope, and the lesions were found only after a random biopsy. This article combines the endoscopic manifestations and clinical features of the lesions in this case to improve the diagnosis of G-NENs.

Chronic Treatment with Somatostatin Analogues in Recurrent Type 1 Gastric Neuroendocrine Tumors

Background: Type 1 gastric neuroendocrine tumors (GC-1) represent an uncommon subtype of neoplasms. Endoscopic resection has been proposed as the treatment of choice; active surveillance may be performed in those smaller than 1 cm, while gastric surgery may be performed for those with frequent recurrences. The antiproliferative effect of somatostatin analogues (SSA) is well known, and their action on GC-1s has been postulated as a chronic treatment to reduce recurrence. Methods: A two-centered, retrospective, observational study that included nine patients (55.6% women) diagnosed with GC-1, receiving long-term treatment with SSA, with a median follow-up from baseline of 22 months, was undertaken. Endoscopic follow-up, extension study, and analytical values of chromogranin A (Cg A) and gastrin were collected. Results: In total, 88.9% of patients presented partial or complete response. Treatment with SSA was the only independent factor with a trend to prevent tumor recurrence (Odds Ratio 0.054; p = 0.005). A nonsignificant tendency toward a decrease in CgA and gastrin was observed; lack of significance was probably related to concomitant treatment with proton pump inhibitors in some patients. Conclusions: Chronic treatment with SSA is a feasible option for recurrent GC-1s that are difficult to manage using endoscopy or gastrectomy. Randomized clinical trials to provide more scientific evidence are still needed.

Gastric and Duodenal Neuroendocrine Tumor Incidentally Found on Endoscopy During the Evaluation of Iron-Deficiency Anemia

Neuroendocrine tumors (NET) are a small fraction of overall gastrointestinal (GI) malignancies. Recently the incidence of NETs has increased due to advancements in diagnostic modality. While solid tumors are easily visible on routine endoscopy, identifying endocrine tumors can be difficult, and low incidence and non-specific presentation can be easily missed on upper gastrointestinal endoscopy (UGIE). The management differs based on the type of tumor and location, but the overall prognosis is good. We present a 59-year-old male with multiple NETs throughout the GI tract, diagnosed on repeat esophagogastroduodenoscopy (EGD) with endoscopic ultrasound (EUS) showing multiple gastric folds. A biopsy of multiple nodules was taken to diagnose type I NET with grade 2 differentiation finally. The mucosal nodules were resected with a band ligator, and surveillance endoscopy was recommended.

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.

Risk of preoperative understaging of duodenal neuroendocrine neoplasms: a plea for caution in the treatment strategy

PURPOSE

Pretreatment staging is the milestone for planning either surgical or endoscopic treatment in duodenal neuroendocrine neoplasms (dNENs). Herein, a series of surgically treated dNEN patients was evaluated to assess the concordance between the pre- and postsurgical staging.

METHODS

Retrospective analysis of patients with a histologically confirmed diagnosis of dNENs, who underwent surgical resection observed at eight Italian tertiary referral centers. The presurgical TNM stage, based on the radiological and functional imaging, was compared with the pathological TNM stage, after surgery.

RESULTS

From 2000 to 2019, 109 patients were included. Sixty-six patients had G1, 26 a G2, 7 a G3 dNEN (Ki-67 not available in 10 patients). In 46/109 patients (42%) there was disagreement between the pre- and postsurgical staging, being it understaged in 42 patients (38%), overstaged in 4 (3%). As regards understaging, in 25 patients (22.9%), metastatic loco-regional nodes (N) resulted undetected at both radiological and functional imaging. Understaging due to the presence of distal micrometastases (M) was observed in 2 cases (1.8%). Underestimation of tumor extent (T) was observed in 12 patients (11%); in three cases the tumor was understaged both in T and N extent.

CONCLUSIONS

Conventional imaging has a poor detection rate for loco-regional nodes and micrometastases in the presurgical setting of the dNENs. These results represent important advice when local conservative approaches, such as endoscopy or local surgical excision are considered and it represents a strong recommendation to include endoscopic ultrasound in the preoperative tools for a more accurate local staging.

Clinical Outcomes of Endoscopic Treatment for Type 1 Gastric Neuroendocrine Tumor

BACKGROUND

Although the rate of early detection and endoscopic treatment of gastric neuroendocrine tumors (NETs) is steadily increasing, there are insufficient studies on the long-term outcomes of endoscopic treatment. Therefore, we aimed to investigate the clinical features and long-term outcomes of endoscopic treatment for type 1 gastric NETs.

METHODS

Subjects who underwent endoscopic treatment for gastric NETs between March 1997 and December 2015 were included. Clinical features and endoscopic treatment outcomes were retrospectively investigated by reviewing medical records.

RESULTS

In total, 125 subjects underwent endoscopic treatment including forceps biopsy (n = 21), argon plasma coagulation (n = 1), endoscopic mucosal resection (EMR, n = 62), and endoscopic submucosal dissection (ESD, n = 41). In total, 103 patients with 114 lesions, who underwent EMR or ESD, were analyzed to evaluate endoscopic and oncologic outcomes. The rates of en bloc resection in the EMR and ESD groups were 91.5% and 97.7%, respectively. Complete resection rates were significantly higher in the ESD group than in the EMR group; it was also higher in < 1-cm small-sized lesions than in 1-2-cm large-sized lesions. Adverse events were similar between the two groups. During a median follow-up period of 63 months, local recurrence rates were 6.5% and 2.4% in the EMR and ESD groups, respectively, and the disease-free survival rate did not differ significantly between the groups.

CONCLUSION

Endoscopic treatment for type 1 gastric NETs less than 2 cm in diameter and confined to mucosal and submucosal layers could be an effective and safe treatment strategy based on the favorable long-term outcome.

Endoscopic mucosal resection: still a reliable therapeutic option for gastrointestinal neuroendocrine tumors

BACKGROUND

Neuroendocrine tumors (NETs), as a rare and heterogeneous category of solid tumors, feature various morphologies and behaviors. In recent years, the incidence of NETs has continued to increase. Endoscopic mucosal resection (EMR) is one of the therapeutic modalities for the treatment of gastric and rectal NETs.

METHODS

We evaluated patients with well-differentiated NETs of the stomach, duodenum, or rectum between 2011 and 2018. In this study, all cases with tumors confined to the mucosal or submucosal layers and smaller than 20 mm were resected using the EMR technique. We used EUS, CT scan, or MRI to exclude patients with advanced disease. All patients were actively monitored for recurrence according to the recommended protocols.

RESULTS

A total of 36 patients with NETs entered the study; 17 (47.2%) were female and the remaining 19 (52.8%) were male, with a total age range of 20-74 years (mean: 52.47 ± 13.47 years). Among the tumors, 31 cases (86.1%) were G1 and the remaining 5 (13.9%) were G2. Based on the pathology reports, 22 tumors (61.1%) were smaller than 1 cm, while the remaining 14 (38.9%) were between 1-2 cm. Twenty-two patients (61.1%) had a margin of specimen involved with the tumor. No recurrence was observed during the mean follow-up time of 63.5 ± 19.8 months (range: 39-103 months). All 36 cases survived during the study period.

CONCLUSION

Conventional EMR procedure provides low chance of R0 (complete resection) achievement in gastrointestinal NETs smaller than 20 mm and limited to the mucosa or sub mucosa. However, it could be an option if patients are closely followed. Postoperative marginal involvement is not a reliable predictor of disease recurrence, which may be explained by the deleterious effect of heat coagulation and cauterization applied during tumor removal.

THE ROLE OF CONVENTIONAL ECHOENDOSCOPY (EUS) IN THERAPEUTIC DECISIONS IN PATIENTS WITH NEUROENDOCRINE GASTROINTESTINAL TUMORS

BACKGROUND

Gastrointestinal neuroendocrine tumors are rare, usually presented as subepithelial or polypoid tumors. Accurate diagnosis and indication of the type of resection are still challenging.

AIM

To determine the effectiveness of echoendoscopy in determining the depth of the lesions (T) identified by endoscopy in order to evaluate surgical and/or endoscopic indication, and to evaluate the results of endoscopic removal in the medium term.

METHODS

Twenty-seven patients were included, all of whom underwent echoendoscopy for TN tumor staging and the evaluation of possible endoscopic resection. The parameters were: lesion size, origin layer, depth of involvement and identified perilesional adenopathies. The inclusion criteria for endoscopic resection were: 1) high surgical risk; 2) those with NET <2 cm; 3) absence of impairment of the muscle itself; and 4) absence of perilesional adenopathies in echoendoscopy and in others without distant metastases. Exclusion criteria were TNE> 2 cm; those with infiltration of the muscle itself; with perilesional adenopathies and distant metastases. The techniques used were: resection with polypectomy loop; mucosectomy with saline injection; and mucosectomy after ligation with an elastic band. The anatomopathological study of the specimens included evaluation of the margins and immunohistochemistry (chromogranin, synaptophysin and Ki 67) to characterize the tumor. Follow-up was done at 1, 6 and 12 months.

RESULTS

Resections with polypectomy loop were performed in 15 patients; mucosectomy in five; mucosectomy and ligation with elastic band in three and the remaining four were referred for surgery. The anatomopathological specimens and immunohistochemical analyzes showed positive chromogranin and synaptophysin, while Ki 67 was less than 5% among all cases. The medium-term follow-up revealed three recurrences. The average size of tumors in the stomach was 7.6 mm and in the duodenum 7.2 mm. Well-demarcated, hypoechoic, homogeneous lesions occurred in 75%; mucous layer in 80%; and the deep and submucosal mucosa in 70%.

CONCLUSIONS

Echoendoscopy proved to be a good method for the study of subepithelial lesions, being able to identify the layer affected by the neoplasm, degree of invasion, echogenicity, heterogeneity, size of the lesion and perilesional lymph node involvement and better indicate the treatment option.

Response and relapse rates after treatment with long-acting somatostatin analogs in multifocal or recurrent type-1 gastric carcinoids: A systematic review and meta-analysis

BACKGROUND

Type-1 gastric neuroendocrine tumors represent a recurring disease and long-acting somatostatin analogs can inhibit both gastrin release and endocrine cell proliferation. The efficacy and timing of this treatment are still unclear. We performed a systematic review of the literature to clarify the role of somatostatin analog treatment in type-1 gastric neuroendocrine tumors.

METHODS

A computerized literature search was performed using relevant keywords to identify all the pertinent articles published in the last 15 years.

RESULTS

Eight studies were included in this systematic review on somatostatin analogs in type-1 gastric neuroendocrine tumors. A complete response rate ranged from 25-100%. When only the six prospective studies were considered, no significant heterogeneity was observed, and the pooled cumulative complete response rate was 84.5% (confidence interval 73.8-92.8). Three studies evaluated the type-1 gastric neuroendocrine tumor recurrence, with a cumulative relapse rate of 30.2% (confidence interval 13.1-50.6) after 34 months.

CONCLUSION

Somatostatin analogs, namely lanreotide and octreotide, have an excellent response rate, with a good safety profile in selected type-1 gastric neuroendocrine tumors, which cannot be safely managed by endoscopic follow-up or resection due to multiple or frequently recurring disease. After therapy discontinuation, the cumulative relapse rate observed after a median 34-month follow-up was relatively high (30.2%).

Clinicopathological characteristics and frequency of multiple rectal neuroendocrine tumors: a single-center retrospective study

BACKGROUND

Rectal multiple neuroendocrine tumors (M-NETs) are rare, with only few epidemiologic reports on the topic. Therefore, their clinicopathological features are not completely known, and the appropriate treatment strategy has not been established.

PURPOSE

This study aimed to compare the clinicopathological malignant potential (lymphatic or venous invasion-positive and lymph node metastasis rates) of M-NETs with that of solitary NETs (S-NETs).

METHODS

We retrospectively investigated 369 patients with NETs of the rectum. Patients who underwent colonoscopy at the Cancer Institute Hospital between January 1979 and 2016 and diagnosed with S-NETs were included, and S-NETs were found in 348 patients. Patients with M-NETs were classified into two groups as follows: patients with < 8 tumors (several (S) group, n = 21) and those with ≥ 8 tumors (numerous (N) group, n = 3).

RESULTS

The overall frequency of M-NETs was 5.7% and that of the N group was 0.8%. The mean tumor diameter in the N group was 6.0 mm (range, 4-8 mm). The lymphatic invasion rates of the S-NETs, and S and N groups of the M-NETs were 8.9%, 5.6%, and 66.7%, respectively. Moreover, the lymph node metastasis rates were 9.2%, 11.1%, and 33.3, respectively.

CONCLUSIONS

While M-NETs in the S and N groups had different characteristics, they were rarer in the N group. The N group may have higher rates of lymphatic invasion and lymph node metastasis regardless of tumor size.

Synchronous Early Gastric Cancer/Neuroendocrine Tumor Associated with Autoimmune Gastritis Completely Resected with Endoscopic Submucosal Dissection

Synchronous early gastric cancer/neuroendocrine tumor (NET) associated with autoimmune gastritis is rare, and its endoscopic and pathological features remain poorly described. Screening esophagogastroduodenoscopy performed on a 71-year-old man revealed a whitish, superficial elevated lesion and a submucosal tumor with redness that appeared slightly centrally depressed. Endoscopic submucosal dissection (ESD) allowed these lesions to be resected with negative margins, and they were diagnosed as tubular adenocarcinoma, well-differentiated type (tub1), pT1a (M) and NET G1, pT1b (SM). To our knowledge, this is the first report describing the endoscopic and pathological findings of synchronous early gastric cancer/NET that was amenable to complete resection with ESD.

Gastric neuroendocrine neoplasias: manifestations and comparative outcomes

Although gastric neuroendocrine neoplasias (gNEN) are an orphan disease, their incidence is rising. The heterogeneous clinical course powers the ongoing discussion of the most appropriate classification system and management. Prognostic relevance of proposed classifications was retrospectively analysed in 142 patients from a single tertiary referral centre. Baseline, management and survival data were acquired for statistical analyses. The distribution according to the clinicopathological typification was gNEN-1 (n = 86/60.6%), gNEN-2 (n = 7/4.9%), gNEN-3 (n = 24/16.9%) and gNEN-4 (n = 25/17.6%), while hypergastrinemia-associated gNEN-1 and -2 were all low-grade tumours (NET-G1/2), formerly termed sporadic gNEN-3 could be subdivided into gNEN-3 with grade 1 or 2 and gNEN-4 with grade 3 (NEC-G3). During follow-up 36 patients died (25%). The mean overall survival (OS) of all gNEN was 14.2 years. The OS differed statistically significant across all subgroups with either classification system. According to UICC 2017 TNM classification, OS differed for early and advanced stages, while WHO grading indicated poorer prognosis for NEC-G3. Cox regression analysis confirmed the independent prognostic validity of either classification system for survival. Particularly careful analysis of the clinical course of gNEN-1 (ECLomas, gastric carcinoids) confirmed their mostly benign, but recurrent and extremely slowly progressive behaviour with low risk of metastasis (7%) and an efficient long-term control by repetitive endoscopic procedures. Our study provides evidence for the validity of current classifications focusing on typing, grading and staging. These are crucial tools for risk stratification, especially to differentiate gNEN-1 as well as sporadic gNET and gNEC (gNEN-3 vs -4).

Finding carcinoid tumor before bariatric surgery. Is preoperative endoscopy necessary? Case report

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The routine use of upper GI endoscopy in preoperative evaluation of bariatric surgery patients still remains controversial.

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The incidence of cancer increases in obese patients.

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The incidence of gastric neuroendocrine tumors in obese patients is higher than the general population (0.6% to 0.0006%).

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Endoscopic evaluation before bariatric surgery is important in terms of revealing many stomach pathologies that may change the treatment of the patient.

Introduction

Carcinoid tumors are endocrine system-related lesions and 4% of the gastrointestinal tract's neuroendocrine tumors (NET) originate from stomach. In recent years, gastric carcinoid tumors have been reported at increasing rates on endoscopies. In this article, we will present a case of gastric carcinoid tumor detected at the upper gastrointestinal (GI) endoscopy during preoperative bariatric surgery workup.

Case presentation

A 55 years old male patient with body mass index (BMI) 46 kg/m² was scheduled for bariatric surgery. Upper GI endoscopy revealed 2 separate 4–5 mm nodular lesions at gastric corpus and antrum. Biopsies were taken and both lesions were reported as neuroendocrine tumors. It was decided that the Laparoscopic sleeve gastrectomy (LSG) operation would be performed because both lesion areas would remain in the extracted part of stomach.

Discussion

The routine use of upper GI endoscopy in preoperative evaluation of bariatric surgery patients still remains controversial.

Conclusion

Upper GI endoscopy is very important in determining various gastric pathologies and determining the most appropriate surgical method before bariatric surgery.

Gastric Carcinoids

Gastric carcinoids, formally named gastric neuroendocrine neoplasms (NENs), are derived from enterochromaffin-like cells of the stomach and are increasingly diagnosed. A majority are designated as type I (related to autoimmune gastritis) and type II (related to gastrinoma) neoplasms that develop secondary to gastrin hypersecretion. Types I and II gastric carcinoids are mostly small-sized (1-2 cm), multiple, low-malignancy potential lesions mainly confined to the gastric mucosa/submucosa. These lesions have an indolent course and low metastatic potential. In contrast, type III gastric carcinoids are single, larger-sized (>2 cm), non-gastrin-related lesions that infiltrate the muscular layers associated with local and distant metastases.

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.

How should incidental NEN of the pancreas and gastrointestinal tract be followed?

Neuroendocrine gastro-entero-pancreatic neoplasms (GEP-NENs) constitute a heterogeneous group of tumors, whose incidence has increased over the years. The most frequent site for primary disease is the stomach followed by small and large intestine, and pancreas. In the last decade, a dramatic growing in the incidence of small, incidental GEP-NENs has been recorded. In parallel, an increasing attitude toward more conservative approaches instead of surgical management has being widely spreading. This is particularly true for small, asymptomatic, pancreatic NEN as for these tumor forms an active surveillance has proven to be safe and feasible. Primary site and biological features of the neoplasms lead to different strategies and indications for surveillance and follow-up. This review focuses on the current evidence on modality and timing of surveillance and conservative treatment of incidentally discovered lesions.

Pedunculated gastric neuroendocrine tumor: a case report

Background and study aims: Gastric neuroendocrine tumors (NETs) are rare lesions that develop from neuroendocrine cells. NETs are classified into 3 types based on the rate of mitosis and Ki-67 labeling index; the NET G1 type is synonymously referred to as carcinoid. Gastric NETs are usually discovered as submucosal tumors during upper gastrointestinal endoscopic examination. This study reports a rare case of pedunculated gastric NET. The lesion was found as a result of gastroendoscopy. The gastric lesion was a pedunculated polyp with a reddish head. We performed endoscopic submucosal dissection and an en-bloc resection of the gastric lesion. The resected specimen was evaluated histopathologically and diagnosed as a carcinoid (NET G1).

Intermittent treatment of recurrent type-1 gastric carcinoids with somatostatin analogues in patients with chronic autoimmune atrophic gastritis

BACKGROUND

Optimal management and treatment of type-1 gastric carcinoids is under debate.

AIMS

This prospective study evaluates the outcome of patients with recurrent type-1 gastric carcinoids treated with somatostatin analogues.

METHODS

From 2000 to 2013, among a population of 107 chronic atrophic gastritis patients, 25 (20% males, median age 62 years) developed type-1 gastric carcinoids and underwent regular clinical and endoscopic follow-up (median 77 months, range 6-165) after the initial treatment. Those patients showing recurrent disease were treated with somatostatin analogues until carcinoid disappearance.

RESULTS

12/25 patients (33% males, median age 65 years) showed recurrent gastric carcinoids and were treated with somatostatin analogues for a median duration of 12 months. Median gastrin and chromogranin A levels, which were 802 pg/mL and 33 U/L, respectively, decreased to 299 pg/mL (p=0.002) and 15.6 U/L (p=0.001) at the end of the treatment. Gastric carcinoids disappeared after a median length of treatment of 12 months. After a median time of 19.5 months from somatostatin analogues discontinuation, 4/12 patients (25% males, median age 56 years) showed a further recurrence. A new cycle of treatment was performed successfully.

CONCLUSIONS

This study confirms that type-1 gastric carcinoids are a recurring disease and somatostatin analogues, administered on 12-month cycles, represent an effective treatment.

Advantage of endoscopic mucosal resection with a cap for rectal neuroendocrine tumors

AIM: To compare the outcomes of endoscopic mucosal resection with a cap (EMR-C) with those of endoscopic submucosal dissection (ESD) for the resection of rectal neuroendocrine tumors.

METHODS: One hundred and sixteen lesions in 114 patients with rectal neuroendocrine tumor (NET) resected with EMR-C or ESD were included in the study. This study was performed at Pusan National University Yangsan Hospital between July 2009 and August 2014. We analyzed endoscopic complete resection rate, pathologic complete resection rate, procedure time, and adverse events in the EMR-C (n = 65) and ESD (n = 51) groups. We also performed a subgroup analysis by tumor size.

RESULTS: Mean tumor size was 4.62 ± 1.66 mm in the EMR-C group and 7.73 ± 3.14 mm in the ESD group (P < 0.001). Endoscopic complete resection rate was 100% in both groups. Histologic complete resection rate was significantly greater in the EMR-C group (92.3%) than in the ESD group (78.4%) (P = 0.042). Mean procedure time was significantly longer in the ESD group (14.43 ± 7.26 min) than in the EMR-C group (3.83 ± 1.17 min) (P < 0.001). Rates of histologic complete resection without complication were similar for tumor diameter ≤ 5 mm (EMR-C, 96%; ESD, 100%, P = 0.472) as well as in cases of 5 mm < tumor diameter ≤ 10 mm (EMR-C, 80%; ESD, 71.0%, P = 0.524).

CONCLUSION: EMR-C may be simple, faster, and more effective than ESD in removing rectal NETs and may be preferable for resection of small rectal NETs.

Endoscopic mucosal resection

EMR has become an established therapeutic option for premalignant and early-stage GI malignancies, particularly in the esophagus and colon. EMR can also aid in the diagnosis and therapy of subepithelial lesions localized to the muscularis mucosa or submucosa. Several dedicated EMR devices are available to facilitate these procedures. Adverse event rates, particularly bleeding and perforation, are higher after EMR relative to other basic endoscopic interventions but lower than adverse event rates for ESD. Endoscopists performing EMR should be knowledgeable and skilled in managing potential adverse events resulting from EMR.

Somatostatin analogs for gastric carcinoids: For many, but not all

Gastric carcinoids (GCs) are classified as: type I, related to hypergastrinemia due to chronic atrophic gastritis (CAG), type II, associated with Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1, and type III, which is normogastrinemic. The management of type-I gastric carcinoids (GC1s) is still debated, because of their relatively benign course. According to the European Neuroendocrine Tumor Society guidelines endoscopic resection is indicated whenever possible; however, it is not often feasible because of the presence of a multifocal disease, large lesions, submucosal invasion or, rarely, lymph node involvement. Therefore, somatostatin analogs (SSAs) have been proposed as treatment for GC1s in view of their antisecretive, antiproliferative and antiangiogenic effects. However, in view of the high cost of this therapy, its possible side effects and the relatively benign course of the disease, SSAs should be reserved to specific subsets of "high risk patients", i.e., those patients with multifocal or recurrent GCs. Indeed, it is reasonable that, after the development of a gastric neuroendocrine neoplasm in patients with a chronic predisposing condition (such as CAG), other enterochromaffin-like cells can undergo neoplastic proliferation, being chronically stimulated by hypergastrinemia. Therefore, definite indications to SSAs treatment should be established in order to avoid the undertreatment or overtreatment of GCs.

Clinical features and management of type I gastric carcinoids

Type I gastric carcinoids (TIGCs) are related to chronic atrophic gastritis and are characterized by hypergastrinemia and hyperplasia of enterochromaffin-like cells. TIGCs are the most frequently diagnosed of all gastric carcinoids, accounting for about 70-80 %. Endoscopically, TIGCs are present as small (<10 mm), polypoid lesions or, more frequently, as smooth, rounded submucosal lesions. Histologically, TIGCs arise in the deep mucosa, with some invading the submucosa. Most TIGCs are well-differentiated tumors, with metastasis being rare. Therefore, patients with TIGCs generally have an excellent prognosis. Among the currently available treatment options are total gastrectomy, partial resection, antrectomy, endoscopic resection, and endoscopic surveillance, although no consensus has been reached on their optimal management. Further studies are needed to develop better management options for patients with TIGC.

Neuroendocrine tumors of the gastrointestinal tract: Case reports and literature review

Neuroendocrine tumors (NET) previously called carcinoid tumors are neoplasms of enterochromaffin/neuroendocrine cell origin which display neurosecretory capacity that may result in the carcinoid syndrome. The annual incidence of patients with NET is 8.4 per 100000; yet many NET remain asymptomatic and clinically undetected. A majority of NET follows a benign course; however, some will display malignant characteristics. NET most commonly occur in the gastrointestinal tract (67%) and bronchopulmonary system (25%). Gastrointestinal NET occur within the stomach, small intestine, liver, and rectum. We report a retrospective study of 11 subjects: Eight with benign carcinoid tumors: duodenal bulb (n = 2), terminal ileum (n = 1), sigmoid colon (n = 2), and rectum (n = 3); three with malignant carcinoid: liver (n = 1) and intra-abdominal site (n = 2). The diagnosis, endoscopic images, outcome, treatment and review of the literature are presented.

Current concepts in the diagnosis and management of type 1 gastric neuroendocrine neoplasms

The vast majority of gastrin-related gastrointestinal neuroendocrine neoplasms (GI-NENs) develop in the context of chronic atrophic gastritis (type 1), a condition closely related to autoimmune thyroid diseases. These neoplasms are defined as gastric NENs type 1 (GNEN1) and have recently been shown to constitute the commonest GI-NENs in a prospective study. GNEN1s are usually multiple and follow a relative indolent course, raising questions regarding the extent that such patients should be investigated and the appropriate therapeutic interventions needed. Recently, a number of consensus statements and guidelines have been published from various societies dealing with the diagnosis and management of GI-NENs. Endocrinologists are among the many different medical specialties involved in GNEN1s diagnosis and management. However, despite recent advances, few randomized trials are available, and thus existing evidence remains relatively weak compared to other malignancies. The purpose of this review is to provide recent evidence along with currently employed modalities addressing the diagnosis, management, long-term follow-up and potential comorbidities of GNEN1s.

Endoscopic submucosal dissection for rectal carcinoid tumour using the Clutch Cutter

BACKGROUND

To reduce the risk of complications related to endoscopic submucosal dissection (ESD) using knives, we developed the Clutch Cutter (CC), which can grasp and incise the target tissue similarly to biopsy techniques using an electrosurgical current. The aim of this study was to evaluate the efficacy and safety of ESD using the CC for removal of rectal carcinoid tumours.

METHODS

Between December 2009 and December 2011, we prospectively enrolled seven patients (seven lesions) on 7 different days. Patients were endoscopically diagnosed with rectal subepithelial lesions (upper rectum, n = 3; lower rectum, n = 4) within the level 3 layer and without lymph node involvement, with the diagnosis confirmed by preliminary endoscopy, endoscopic ultrasound and endoscopic biopsies. ESD using the CC was performed in all cases, and the therapeutic efficacy, safety and tumour recurrence were assessed.

RESULTS

All lesions were treated easily and safely, and there were no inadvertent incisions. En bloc resection was obtained in all cases, and histologic tumour-free lateral/basal margins were obtained in six of the seven patients. No delayed haemorrhage, perforation or tumour recurrence occurred.

CONCLUSION

ESD using the CC appears to be an easy, safe and technically efficient method for resecting rectal carcinoid tumour.

Endoscopic mucosal resection with circumferential incision for treatment of rectal carcinoid tumours

Background

Endoscopic mucosal resection (EMR) is simple and quick and has low complication rates. However, the disadvantage of local recurrence or remnant rate limits the use of this technique. We aimed to analyse the outcomes of conventional EMR and EMR with circumferential incision (CIEMR), a simplified modification of EMR, in the endoscopic treatment of rectal carcinoid tumours.

Methods

A total of 59 consecutive patients with rectal carcinoid tumours without regional lymph node enlargement confirmed by endoscopic ultrasonography were included in the study. These patients underwent endoscopic treatment from January 2009 to September 2011 and were randomly designated into CIEMR (n = 31) or EMR group (n = 28). En bloc resection rate, pathological complete resection rate, procedure time, complications and follow-up outcomes were analysed.

Results

The en bloc resection rate was not significantly different between the CIEMR and EMR groups (100% versus 96.55%, P > 0.05). The pathological complete resection rate was higher in the CIEMR group than in the EMR group (96.7% versus 82.14%, P < 0.05). The overall complication rate, delayed bleeding and procedure time were not significantly different between the two groups. No recurrence was observed in either the EMR or CIEMR group.

Conclusions

CIEMR optimises the procedure of EMR and simplifies the technique of endoscopic submucosal dissection; thus, it has a better histologically complete resection rate and more acceptable complication rate than EMR. Thus, CIEMR may be preferable to conventional EMR for resection of rectal carcinoid tumours less than 15 mm.

Long-term follow up of endoscopic resection for type 3 gastric NET

AIM

To clarify the short and long-term results and to prove the usefulness of endoscopic resection in type 3 gastric neuroendocrine tumors (NETs).

METHODS

Of the 119 type 3 gastric NETs diagnosed from January 1996 to September 2011, 50 patients treated with endoscopic resection were enrolled in this study. For endoscopic resection, endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) was used. Therapeutic efficacy, complications, and follow-up results were evaluated retrospectively.

RESULTS

EMR was performed in 41 cases and ESD in 9 cases. Pathologically complete resection was performed in 40 cases (80.0%) and incomplete resection specimens were observed in 10 cases (7 vs 3 patients in the EMR vs ESD group, P = 0.249). Upon analysis of the incomplete resection group, lateral or vertical margin invasion was found in six cases (14.6%) in the EMR group and in one case in the ESD group (11.1%). Lymphovascular invasions were observed in two cases (22.2%) in the ESD group and in one case (2.4%) in the EMR group (P = 0.080). During the follow-up period (43.73; 13-60 mo), there was no evidence of tumor recurrence in either the pathologically complete resection group or the incomplete resection group. No recurrence was reported during follow-up. In addition, no mortality was reported in either the complete resection group or the incomplete resection group for the duration of the follow-up period.

CONCLUSION

Less than 2 cm sized confined submucosal layer type 3 gastric NET with no evidence of lymphovascular invasion, endoscopic treatment could be considered at initial treatment.

Long-term results of endoscopic resection for type I gastric neuroendocrine tumors

BACKGROUND

A number of different therapies, including endoscopic resection, have been suggested for the treatment of Type 1 gastric neuroendocrine tumors (NETs). The current study aimed to determine the long-term efficacy of endoscopic resection for Type 1 gastric NETs.

METHODS

Twenty-two patients (from 1999 to 2012) with Type 1 gastric NETs were included in the study. All patients were treated with endoscopic resection and received regular followed-up appointments at a tertiary referral center.

RESULTS

All patients were initially diagnosed with hypergastrinemia, atrophic gastritis and intestinal metaplasia. Polyps' diameters were >1 cm in 4 patients, and between 0.5 and 1 cm in 18 patients. All detectable lesions were successfully resected. One patient required surgery due to gastric perforation during endoscopic mucosal resection. Recurrence was detected in four patients (18%) and endoscopic resection was performed again. Local or distant metastasis was not observed in any patient during follow-up. Median follow-up time was 7 years, with a maximum of 14 years. Seventeen patients (78%) completed a 5-year follow-up period, and overall disease-free survival rate was 100%.

CONCLUSIONS

Long-term follow-ups with 22 patients suggest that endoscopic resection of Type 1 gastric NETs is a safe and effective treatment option with a relatively low recurrence rate.

Endoscopic treatment for early foregut neuroendocrine tumors

Foregut neuroendocrine tumors (NETs) include those arising in the esophagus, stomach, pancreas, and duodenum and seem to have a broad range of clinical behavior from benign to metastatic. Several factors including the advent of screening endoscopy may be related to increased incidence of gastrointestinal NETs; thus, many foregut NETs are diagnosed at an early stage. Early foregut NETs, such as those of the stomach and duodenum, can be managed with endoscopic treatment because of a low frequency of lymph node and distant metastases. However, controversy continues concerning the optimal management of early foregut NETs due to a lack of controlled prospective studies. Several issues such as indications, technical issues, and outcomes of endoscopic treatment for early foregut NETs are reviewed based on some published studies.

Endoscopic resection for gastrointestinal neuroendocrine tumors

Gastrointestinal (GI) and neuroendocrine tumors (NETs) can be treated by mini-invasive endoscopic resection when localized in the superficial layers of the bowel wall and their size is <20 mm. Endoscopic diagnosis of NETs is usually incidental or suspected after clinical, laboratory or imaging findings. Endoscopic mucosal resection is the most commonly used technique for NET removal, endoscopic submucosal dissection is indicated in selected cases, while papillectomy is feasible for ampullary lesions. Histopathologic assessment of the resection margin (circumferential and deep) is important for staging. Incidence of endoscopic mucosal resection-/endoscopic submucosal dissection-related complications for removal of GI NETs are similar to those reported for other GI lesions. Endoscopic follow-up is based on histopathologic characteristics of the resected NETs and its site. NETs >20 mm in size, with penetration of the muscle layer and/or serosa are at high risk for metastases and surgical approach is recommended when feasible.

Unexpected endoscopic full-thickness resection of a duodenal neuroendocrine tumor

A 57-year-old man underwent endoscopy for investigation of a duodenal polyp. Endoscopy revealed a hemispheric submucosal tumor, about 5 mm in diameter, in the anterior wall of the duodenal bulb. Endoscopic biopsy disclosed a neuroendocrine tumor histologically, therefore endoscopic mucosal resection was conducted. The tumor was effectively and evenly elevated after injection of a mixture of 0.2% hyaluronic acid and glycerol at a ratio of 1:1 into the submucosal layer. A small amount of indigo-carmine dye was also added for coloration of injection fluid. The lesion was completely resected en bloc with a snare after submucosal fluid injection. Immediately, muscle-fiber-like tissues were identified in the marginal area of the resected defect above the blue-colored layer, which suggested perforation. The defect was completely closed with a total of 9 endoclips, and no symptoms associated with peritonitis appeared thereafter. Histologically, the horizontal and vertical margins of the resected specimen were free of tumor and muscularis propria was also seen in the resected specimen. Generally, endoscopic mucosal resection is considered to be theoretically successful if the mucosal defect is colored blue. The blue layer in this case, however, had been created by unplanned injection into the subserosal rather than the submucosal layer.

Correlation between a short-term intravenous octreotide suppression test and response to antrectomy in patients with type-1 gastric neuroendocrine tumours

BACKGROUND

Type-1 gastric neuroendocrine tumours (NETs) arise in some patients with chronic hypergastrinaemia secondary to autoimmune atrophic gastritis. Patients with small tumours are usually managed conservatively, because their prognosis is very good. However, larger tumours may require surgical intervention. Many type-1 gastric NETs regress following antrectomy because this removes the source of hypergastrinaemia. However, some tumours do not regress following antrectomy and additional surgery may be required. An octreotide suppression test has been previously suggested as a means to assess whether type-1 gastric NETs are likely to regress following antrectomy.

AIM

To prospectively examine the role of a short-term intravenous octreotide suppression test in predicting type-1 gastric NET regression in five patients who subsequently underwent antrectomy.

MATERIALS AND METHODS

Serum gastrin concentrations and gastric corpus and tumour histidine decarboxylase mRNA abundances were assessed in patients with type-1 gastric NETs before and 72 h after the administration of 25 µg/h intravenous octreotide. Gastric tumour response was assessed endoscopically following subsequent antrectomy.

RESULTS

All patients showed significant decreases in serum gastrin concentrations as well as corpus and tumour biopsy histidine decarboxylase mRNA abundance following octreotide infusion. All patients also showed resolution of hypergastrinaemia following subsequent antrectomy. However, tumour regression was only observed in four of the five patients. One patient had a persistent tumour 3 years after antrectomy and required additional surgical resection.

CONCLUSION

A positive octreotide suppression test result does not always predict response to antrectomy in patients with type-1 gastric NETs. Assessment of gastric mucosal responses to a gastrin/CCK-2 receptor antagonist may therefore also be helpful.

Long-term follow-up of a large series of patients with type 1 gastric carcinoid tumors: data from a multicenter study

OBJECTIVE

To study the clinical presentation, diagnostic approach, response to treatment, and the presence of other pathologies in patients with gastric carcinoid type 1 (GC 1) tumors.

DESIGN AND METHODS

Retrospective analysis of 111 patients from four institutions and a mean follow-up of 76 months.

RESULTS

The main indications for gastroscopy were upper gastrointestinal tract symptoms. The mean number of lesions, maximum tumoral diameter, and percentage of cells expressing Ki-67 labeling index were 3.6±3.8, 8±12.1 mm and 1.9±2.4% respectively. Serum gastrin and chromogranin A (CgA) levels were elevated in 100/101 and 85/90 patients respectively. Conventional imaging studies demonstrated pathology in 9/111 patients. Scintigraphy with radiolabeled octreotide was positive in 6/60 without revealing any additional lesions. From the 59 patients who had been followed-up without any intervention, five developed tumor progression. Thirty-two patients were treated with long-acting somatostatin analogs (SSAs), leading to a significant reduction of gastrin and CgA levels, number of visible tumors, and CgA immune-reactive tumor cells in 28, 19, 27, and 23 treated patients respectively. Antrectomy and/or gastrectomy were initially performed in 20 patients and a complete response was achieved in 13 patients. The most common comorbidities were vitamin B12 deficiency, thyroiditis, and parathyroid adenomas.

CONCLUSIONS

Most GCs1 are grade 1 (82.7%) tumors presenting with stage I (73.9%) disease with no mortality after prolonged follow-up. Ocreoscan did not provide further information compared with conventional imaging techniques. Treatment with SSAs proved to be effective for the duration of administration.

Clinical impact of endoscopic submucosal dissection for gastric neuroendocrine tumors: a retrospective study from mainland China

As a minimally invasive technique, endoscopic resection may benefit patients diagnosed with early stage gastrointestinal neuroendocrine tumors (NETs). However, no studies have yet been published in which endoscopic submucosal dissection (ESD) has been applied for gastric NETs. For the first time a research group in China applied ESD to remove gastric NETs, and indicated that ESD should be considered for treatment of eligible gastric NETs because the technique shows a high histologically complete resection rate, provides accurate histopathological evaluation, has a low complication rate, and can be performed within a reasonable timeframe.

Gastric and duodenal neuroendocrine tumours

Gastric neuroendocrine neoplasms (NENs) are increasing in frequency and have a varied spectrum with regard to histology, clinicopathologic background, stage, and prognosis. They are usually discovered incidentally, are for the most part benign and are associated with hypergastrinaemia (secondary either to chronic atrophic gastritis or rarely Zollinger-Ellison syndrome; types 1 and 2, respectively) or more rarely sporadic type 3. Applications of recent staging and grading systems - namely using Ki-67 proliferative indices - (from ENETS and WHO 2010) can be particularly helpful in further categorising these tumours. The natural history of Type 1 gastric carcinoids is generally (>95%) favourable and simple surveillance is usually recommended for small (<1 cm) T1 tumours, with local (endoscopic or surgical) resection for larger lesions. Other potential therapies such as somatostatin analogues and gastrin receptor antagonists may offer newer therapeutic possibilities. Rarely, gastric NENs have a malignant course and this is usually confined to Type 2 and especially Type 3 tumours; the latter mimic the biological course of gastric adenocarcinoma and require radical oncological therapies. Most duodenal NENs, apart from gastrinomas (that are not dealt with here) are sporadic and non functional. They are also increasing in frequency probably due to incidental discovery at endoscopy or imaging for other reasons and this may account for their overall good prognosis. Peri-ampullary and ampullary NENs may have a more aggressive outcome and should be carefully appraised and treated (often with surgical resection).

Endoscopic submucosal dissection for foregut neuroendocrine tumors: An initial study

AIM: To evaluate the feasibility and efficacy of endoscopic submucosal dissection (ESD) for foregut neuroendocrine tumors (NETs).

METHODS: From April 2008 to December 2010, patients with confirmed histological diagnosis of foregut NETs were included. None had regional lymph node enlargement or distant metastases to the liver or lung on preoperative computerized tomography scanning or endoscopic ultrasonography (EUS). ESD was attempted under general anesthesia. After making several marking dots around the lesion, a mixture solution was injected into the submucosa. The mucosa was incised outside the marking dots. Dissection of the submucosal layer beneath the tumor was performed under direct vision to achieve complete en bloc resection of the specimen. Tumor features, clinicopathological characteristics, complete resection rate, and complications were evaluated. Foregut NETs were graded as G1, G2, or G3 on the basis of proliferative activity by mitotic count or Ki-67 index. All patients underwent regular follow-up to evaluate for any local recurrence or distant metastasis.

RESULTS: Those treated by ESD included 24 patients with 29 foregut NETs. The locations of the 29 lesions are as follows: esophagus (n = 1), cardia (n = 1), stomach (n = 23), and duodenal bulb (n = 4). All lesions were found incidentally during routine upper gastrointestinal endoscopy for other indications, and none had symptoms of carcinoid syndrome. Preoperative EUS showed that all tumors were confined to the submucosa. Among the 24 gastric lesions, 16 lesions in 11 patients were type I gastric NETs arising in chronic atrophic gastritis with hypergastrinemia, while the other 8 solitary lesions were type III because of absence of atrophic gastritis in these cases. All of the tumors were removed in an en bloc fashion. The average maximum diameter of the lesions was 9.4 mm (range: 2-30 mm), and the procedure time was 20.3 min (range: 10-45 min). According to the World Health Organization 2010 classification, histological evaluation determined that 26 lesions were NET-G1, 2 gastric lesions were NET-G2, and 1 esophageal lesion was neuroendocrine carcinoma (NEC). Complete resection was achieved in 28 lesions (28/29, 96.6%), and all of them were confined to the submucosa in histopathologic assessment with no lymphovascular invasion. The remaining patient with NEC underwent additional surgery because the resected specimens revealed angiolymphatic and muscularis invasion, as well as incomplete resection. Delayed bleeding occurred in 1 case 3 d after ESD, which was managed by endoscopic treatment. There were no procedure-related perforations. During a mean follow-up period of 24.4 mo (range: 12-48 mo), local recurrence occurred in only 1 patient 7 mo after initial ESD. This patient successfully underwent repeat ESD. Metastasis to lymph nodes or distal organs was not observed in any patient. No patients died during the study period.

CONCLUSION: ESD appears to be a safe, feasible, and effective procedure for providing accurate histopathological evaluations and curative treatment for eligible foregut NETs.

Gastric neuroendocrine tumours

BACKGROUND

Gastric neuroendocrine tumours (NETs) are increasingly recognised, and management decisions may be difficult due to an incomplete understanding of aetiology, natural history and optimum therapy. This article presents a current understanding based on recent advances in epidemiology, classification, molecular profiling, and treatment.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Gastric NETs may be divided into three clinical prognostic groups: type I is associated with autoimmune atrophic gastritis and hypergastrinaemia, type II is associated with Zollinger-Ellison syndrome, and type III lesions are gastrin-independent, have the greatest metastatic potential and poorest prognosis. There has been an increased frequency of gastric NETs reported. Management approaches have evolved in parallel with advances in endoscopic staging and surgery, as well as improved understanding of the biology and natural history of NETs.

CONCLUSIONS

Gastric NETs present a spectrum of activity from indolent tumours to metastatic malignancy. Treatment decisions for patients must be individualised and are best managed by a multidisciplinary team approach. The current evidence base is limited to small series and efforts to treat patients within clinical networks of expertise are warranted.

Unusually aggressive type 1 gastric carcinoid: a case report with a review of the literature

Gastric carcinoids are rare tumors of the stomach. Gastric carcinoid type 1 is associated with chronic atrophic gastritis, and because of a low metastatic potential, is the most benign type. Death from metastatic disease has been reported in only three patients in a review including 724 cases. The present report refers to a 60-year-old man who was affected by type 2 diabetes mellitus and pernicious anemia and died from metastatic gastric carcinoid type 1. In 1998, a well-differentiated 1.2 cm gastric neuroendocrine tumor, immunoreactive for chromogranin A, with a Ki-67 index less than 2% and with infiltration to the submucosal layer was diagnosed and enucleated. In 2002, a new well-differentiated gastric endocrine tumor 6 mm in size with a Ki-67 of approximately 2% was detected, and endoscopic ultrasound confirmed it to be limited to the submucosal layer. The patient refused antrectomy and started long-acting somatostatin analog (lanreotide) in 2005 when the Ki-67 index was 7%, but he stopped the treatment after 4 months. In 2007, despite previous endoscopic stability, endoscopic ultrasound showed an infiltrating gastric lesion of 7 cm. At surgery, the disease appeared to be extended to the liver and to the peritoneum (well-differentiated endocrine carcinoma, Ki-67 40%) with both hepatic and massive peritoneal metastases. A regimen of somatostatin analog was soon restarted; however, the disease continued to spread, and the patient died 6 months later. Overall, despite their generally benign course, type 1 gastric carcinoids may have malignant potential, a finding that should be considered when planning the medical workup of these patients.

Endoscopic ultrasonography-guided diagnosis of subepithelial tumors

Subepithelial lesions are frequently discovered during routine endoscopic examinations. These lesions represent a wide spectrum of heterogeneous benign to malignant conditions. Most of these lesions are asymptomatic. There is no consensus regarding how to manage these lesions. Over the last 2 decades, the approach to these lesions has significantly improved owing to the introduction of endoscopic ultrasonography, fine-needle aspiration, immunohistochemical staining methods, and different treatment options. This article discusses the nature of subepithelial lesions, focusing on the most recent developments that use endoscopic ultrasonography to diagnose and manage these lesions.

Review of the pathogenesis, diagnosis, and management of type I gastric carcinoid tumor

Gastric carcinoid tumors comprise 7% of all gastrointestinal carcinoids and have significantly increased in incidence over the past few decades. Seventy to 80% of gastric carcinoids are type I, which usually are clinically asymptomatic and found incidentally at endoscopic evaluation for abdominal pain or anemia. In this review, advances in understanding the pathophysiology of type I gastric carcinoid are highlighted. In addition, various current diagnostic and treatment options are discussed. Although type I carcinoids generally hold a benign course, rigorous investigation is needed to ensure accurate diagnosis and optimal treatment. This includes appropriate diagnostic procedures and imaging and accurate staging of tumor. Tumor size, depth of invasion, presence of metastasis, and the tumor's gastrin dependency dictate treatment options. Appropriate treatments can consist of endoscopic resection, antrectomy, medical management, or frequent follow-up. This article provides a systematic method of evaluating and treating type I gastric carcinoid.

Type I gastric carcinoids: a prospective study on endoscopic management and recurrence rate

BACKGROUND

Type I gastric carcinoids (TIGCs) are neuroendocrine neoplasms arising from enterochromaffin-like cells in atrophic body gastritis. Data regarding their evolution in prospective series are scarce, thus treatment and follow-up are not codified. Our aim was to evaluate clinical outcome and recurrence in TIGCs managed by endoscopic approach.

METHODS

33 patients (24 females; median age 65 years, range 23-81) were included and managed through endoscopic follow-up every 6-12 months, with lesion removal and multiple gastric biopsies. Baseline clinical and histological features were analyzed as risk factors by Cox regression.

RESULTS

At diagnosis, 7 tumors were intramucosal carcinoids and 26 were polyps (median diameter 5 mm, range 2-20), multiple in 17 patients. Associated severe atrophy was present in 21 cases (63.6%), while mild atrophy was found in 6 cases (18.2%). During a 46-month median follow-up, survival was 100% and no metastases occurred. One patient developed a less-differentiated carcinoid that was radically treated by surgery. 21 patients (63.6%) had recurrence after a median of 8 months, 14 of these (66.6%) had a second recurrence after a median of 8 months following the previous carcinoid removal. Median recurrence-free survival was 24 months. Neither clinical nor biochemical recurrence-predicting factors were found.

CONCLUSIONS

Although about 60% of TIGCs had recurrence after endoscopic resection, endoscopic management may be considered safe and effective.