Neuroendocrine tumours of the small intestine

Small Bowel Neuroendocrine Tumors-10-Year Experience of the Ottawa Hospital (TOH)

(1) Aim: The prevalence and incidence of small bowel NETs have increased significantly over the past two decades. This study aims to report the 10-year experience of SB-NET management at a regional cancer center in Canada. (2) Materials and methods: We conducted a retrospective study of the clinical and pathological data of patients diagnosed with biopsy-proven SB-NET at The Ottawa Hospital (TOH), Ottawa, Canada between 2011 and 2021. We report the clinicopathological characteristics of these patients, as well as their outcomes data, including survival rates. (3) Results: Between 2011 and 2021, a total of 177 SB-NET cases were identified with 51% (n = 91) of cases being males. The most common sites of the tumors were the ileum 53% (n = 94), followed by the duodenum 9% (n = 16) and jejunum 7% (n = 12). Approximately 24% (n = 42) of the patients had symptoms for over six months prior to diagnosis and 18% (n = 32) had functioning SB-NET during the course of the disease. The majority of patients had locally advanced or metastatic disease at the time of presentation with stage III, and stage IV representing 42% (n = 75), and 41% (n = 73) respectively. The majority of patients 84% (n = 148) had well-differentiated histology. One hundred twenty patients underwent surgical resection of the primary tumor including 28 patients (16%) with limited metastatic disease. A total of 21 patients (18%) had recurrence after curative surgery. A total of 62 patients (35%) received first-line somatostatin analog (SSA) therapy for unresectable disease and seven patients had PRRT after progression on SSA. Five years OS was 100%, 91%, 97%, and 73% for stages I, II, III, and IV respectively. In univariate analysis, carcinoid symptoms, T stage, and differentiation were significant predictors for worse overall survival, but not RFS. (4) Conclusions: Compared to published historical controls, our study suggests improvement in the 5-year survival rate of SB-NETs over the last 10 years.

Neuroendocrine neoplasms in the context of inherited tumor syndromes: a reappraisal focused on targeted therapies

PURPOSE

Neuroendocrine neoplasms can occur as part of inherited disorders, usually in the form of well-differentiated, slow-growing tumors (NET). The main predisposing syndromes include: multiple endocrine neoplasias type 1 (MEN1), associated with a large spectrum of gastroenteropancreatic and thoracic NETs, and type 4 (MEN4), associated with a wide tumour spectrum similar to that of MEN1; von Hippel-Lindau syndrome (VHL), tuberous sclerosis (TSC), and neurofibromatosis 1 (NF-1), associated with pancreatic NETs. In the present review, we propose a reappraisal of the genetic basis and clinical features of gastroenteropancreatic and thoracic NETs in the setting of inherited syndromes with a special focus on molecularly targeted therapies for these lesions.

METHODS

Literature search was systematically performed through online databases, including MEDLINE (via PubMed), and Scopus using multiple keywords' combinations up to June 2022.

RESULTS

Somatostatin analogues (SSAs) remain the mainstay of systemic treatment for NETs, and radiolabelled SSAs can be used for peptide-receptor radionuclide therapy for somatostatin receptor (SSTR)-positive NETs. Apart of these SSTR-targeted therapies, other targeted agents have been approved for NETs: the mTOR inhibitor everolimus for lung, gastroenteropatic and unknown origin NET, and sunitinib, an antiangiogenic tyrosine kinase inhibitor, for pancreatic NET. Novel targeted therapies with other antiangiogenic agents and immunotherapies have been also under evaluation.

CONCLUSIONS

Major advances in the understanding of genetic and epigenetic mechanisms of NET development in the context of inherited endocrine disorders have led to the recognition of molecular targetable alterations, providing a rationale for the implementation of treatments and development of novel targeted therapies.

Fortuitous discovery of an early neuroendocrine tumor during appendicular peritonitis

Introduction

Materials and methods

Results

Conclusion

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Neuroendocrine tumors of the small bowel are rare but represent the most frequent histological type at this level.

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Their incidence is increasing thanks to the evolution of diagnostic means.

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These tumors are most often diagnosed incidentally during the workup of aspecific digestive disorders or during hormonal hypersecretion syndrome or rarely by a complication.

Genetic Drivers of Ileal Neuroendocrine Tumors

Simple Summary

Although ileal neuroendocrine tumors are the most common tumors of the small intestine, they are not well-defined at the genetic level. Unlike most cancers, they have an unusually low number of mutations, and also lack recurrently mutated genes. Moreover ileal NETs have been difficult to study in the laboratory because there were no animal models and because cell lines were generally unavailable. But recent advances, including the first ileal NET mouse model as well as methods for culturing patient tumor samples, have been described and have already helped to identify IGF2 and CDK4 as two of the genetic drivers for this tumor type. These advances may help in the development of new treatments for patients.

Abstract

The genetic causes of ileal neuroendocrine tumors (ileal NETs, or I-NETs) have been a mystery. For most types of tumors, key genes were revealed by large scale genomic sequencing that demonstrated recurrent mutations of specific oncogenes or tumor suppressors. In contrast, genomic sequencing of ileal NETs demonstrated a distinct lack of recurrently mutated genes, suggesting that the mechanisms that drive the formation of I-NETs may be quite different than the cell-intrinsic mutations that drive the formation of other tumor types. However, recent mouse studies have identified the IGF2 and RB1 pathways in the formation of ileal NETs, which is supported by the subsequent analysis of patient samples. Thus, ileal NETs no longer appear to be a cancer without genetic causes.

Radiology of the neuroendocrine neoplasms of the gastrointestinal tract: a comprehensive review

Neuroendocrine neoplasms (NENs) are a group of neoplasms arising from the diffuse endocrine system (DES). The gastrointestinal tract (GIT) is the most common site of NEN. The WHO classification divides NEN into three broad categories viz. well-differentiated NENs, poorly differentiated NENs, and mixed neuroendocrine-non-neuroendocrine neoplasms. All GIT NEN have the potential to synthesize and secrete various bioactive substances which may lead to various clinical syndromes. The NEN may occur anywhere in the GIT and exhibit varying clinical presentation, prognosis, and metastatic potential. Further, some tumors show association with familial syndromes like multiple endocrine neoplasia type 1 and neurofibromatosis type 1. Ultrasonography, computed tomography (CT), magnetic resonance imaging, and positron emission tomography-CT are the imaging modalities useful in the diagnosis, localization, and staging of GIT NEN. Management depends on the site, size, grade, and stage of the tumor with interventional radiology playing a significant role in some cases. This imaging review describes the role of a radiologist in the management of GIT NEN.

A Patient with Multiple Gastrointestinal Carcinoid Tumours Presenting with Jejunal Intussusception

Carcinoid tumours are neuroendocrine tumours which arise from the enterochromaffin cells in the gastrointestinal and bronchopulmonary systems. The presentation of multiple gastrointestinal carcinoids with jejunal intussusception is rare, and the diagnosis may be challenging. A 49-year-old patient with adult onset bronchial asthma presented with pain around the umbilical region for 1-day duration. Physical examination revealed only mild abdominal tenderness. Abdominal computed tomography revealed small bowel intussusception with two separate highly vascular tumours arising in the small bowel mesentery. Exploratory laparotomy was done, with resection of the tumours arising from the small bowel mesentery and the proximal jejunum causing the intussusception which were excised. Histopathological diagnosis confirmed the presence of a Grade 1 carcinoid tumour of classic type. After surgery, he had an uneventful recovery and was asymptomatic. Carcinoid tumours are a very rare cause of adult intussusception. So far, there have been only two reported cases of jejunal intussusception secondary to carcinoid tumours. These will require a combination of surgical intervention and systemic therapy in selective cases for complete management.

Clinical Features, Management, and Molecular Characteristics of Familial Small Bowel Neuroendocrine Tumors

Small bowel neuroendocrine tumors are rare tumors with an increasing incidence over the last several decades. Early detection remains challenging because patients commonly develop symptoms late in the disease course, often after the tumors have metastasized. Although these tumors were thought to arise from sporadic genetic mutations, large epidemiological studies strongly support genetic predisposition and increased risk of disease in affected families. Recent studies of familial small bowel neuroendocrine tumors have identified several novel genetic mutations. Screening for familial small bowel neuroendocrine tumors can lead to earlier diagnosis and improved patient outcomes. This review aims to summarize the current knowledge of molecular changes seen in familial small bowel neuroendocrine tumors, identify clinical features specific to familial disease, and provide strategies for screening and treatment.

Unravelling the Mysteries of the Mesentery

The mesentery and its folds tether the small bowel loops to the posterior abdominal wall. It transmits nerves, vessels, and lymph ensconced in a fatty sponge layer wrapped in a thin glistening peritoneum, from and to the small bowel. Not only does this flexible dynamic fatty apron house various localized primary benign and malignant lesions, it is often involved in and gives an indication of generalized or systemic diseases in the body. An understanding of the anatomy, components, and function of the mesentery helps to classify mesenteric abnormalities. This further allows for characterizing radiological patterns and appearances specific to certain disease entities. Recent reviews of mesenteric anatomy have kindled new interest in its function and clinical applications, heralding the possibility of revision of its role in diseases of the abdomen.

Neuroendocrine neoplasia of the gastrointestinal tract revisited: towards precision medicine

Over the past 5 years, a number of notable research advances have been made in the field of neuroendocrine cancer, specifically with regard to neuroendocrine cancer of the gastrointestinal tract. The aim of this Review is to provide an update on current knowledge that has proven effective for the clinical management of patients with these tumours. For example, for the first time in the tubular gastrointestinal tract, well-differentiated high-grade (grade 3) tumours and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are defined in the WHO classification. This novel classification enables efficient identification of the most aggressive well-differentiated neuroendocrine tumours and helps in defining the degree of aggressiveness of MiNENs. The Review also discusses updates to epidemiology, cell biology (including vesicle-specific components) and the as-yet-unresolved complex genetic background that varies according to site and differentiation status. The Review summarizes novel diagnostic instruments, including molecules associated with the secretory machinery, novel radiological approaches (including pattern recognition techniques), novel PET tracers and liquid biopsy combined with DNA or RNA assays. Surgery remains the treatment mainstay; however, peptide receptor radionuclide therapy with novel radioligands and new emerging medical therapies (including vaccination and immunotherapy) are evolving and being tested in clinical trials, which are summarized and critically reviewed here.

A Modified Duodenal Neuroendocrine Tumor Staging Schema Better Defines the Risk of Lymph Node Metastasis and Disease-free Survival

Duodenal neuroendocrine tumors are rare but increasing in incidence and optimal management is hindered by lack of duodenum-specific staging. Duodenal carcinoids were identified in the Surveillance, Epidemiology and End Results tumor registry. Depth of invasion was defined as limited to lamina propria (LP), invading muscularis propria (MP), through muscularis propria (TMP), and through serosa (S). Nine hundred forty-nine patients were identified with majorities being male (57%), white (70%), and node-negative (87%). Tumor size (cm) was less than 1, 47 per cent; 1 to 2, 35 per cent; and greater than 2, 8 per cent with 76 per cent LP. Lymph node (LN) involvement was associated with age, depth of invasion (LP 4%, MP 28%, TMP 54%, and S 57%) and size (less than 1 cm, 3%; 1 to 2 cm, 13%; and greater than 2 cm, 40%). Using the current T staging, LN involvement was: T1 (LP) 2 per cent, T2 (MP or greater than 1 cm) 13 per cent, T3 (TMP) 54 per cent, and T4 (S) 57 per cent. We reclassified current T1 to T1a and current T2 stage to T1b (1 to 2 cm and LP) and T2 (MP or greater than 2 cm). LN metastasis for T1b tumors was 4.7 per cent compared with 20.8 per cent for T2. The resulting TNM classification better defines 5-year disease-specific survival. Our modified staging schema identifies a low-risk group (T1a and T1b) that may be considered for local therapy.

Double contrast-enhanced ultrasonography of a small intestinal neuroendocrine tumor: a case report of a recommendable imaging modality

A 57-year-old male presenting with spontaneously relieved abdominal cramp and distension was admitted to the West China Hospital. The diagnosis remained unclear after colonoscopy and computed tomography. Double contrast-enhanced ultrasonography was then performed and a neoplasm in the small intestine was suspected, supported by a thin-section computed tomography and positron emission tomography/computed tomography. This was confirmed pathologically after surgery to be a small intestinal G1 neuroendocrine tumor. Surgery was performed to remove approximately 25 cm of small bowel and a 3-cm solid mass located in the mesentery. The patient had a complete recovery and was tumor-free at the final follow-up. Small intestinal tumors including neuroendocrine tumors have always posed a diagnostic challenge. This case indicated that double contrast-enhanced ultrasonography is feasible in detection of small intestinal neuroendocrine tumors, and it may be an advisable approach assisting diagnosis of small intestinal tumors.

Carcinoid Tumor: Advances in Treatment Options

Small bowel neoplasms are rare, accounting for only 3%-6% of all gastrointestinal neoplasms. Carcinoid tumors represent a large portion of these (20%-30%), making them the second most common small bowel malignancy after adenocarcinoma. Gastrointestinal carcinoids constitute 70% of all neuroendocrine tumors, and out of those, 42% originate in the small bowel. They are predominantly seen in older patients around the age of 65 years. From 1973 to 2004, there has been more than a fourfold increase in the incidence of carcinoid tumors. This can be probably due to increased diagnostic accuracy rather than an actual increase in the number of new cases. The workup of a suspicious case of gastrointestinal bleeding consists of esophagogastroduodenoscopy and/or colonoscopy, and other imaging tests including video capsule endoscopy and balloon-assisted endoscopy. Management of the tumors is dependent on the size and location of the lesion. Treatment options include surgery, endoscopic removal of tumors, and various immunotherapy and chemotherapeutic agents.

[Modern sonographic imaging of abdominal neuroendocrine tumors]

BACKGROUND

Radiological and nuclear medical diagnostics play an important role in the work-up of patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET). The sonographic examination, including contrast-enhanced examination, depicts an initial imaging modality to screen for NET. This report describes the sonomorphological behavior of ileal and pancreatic NET as well as hepatic metastases from NET.

CLINICAL/METHODICAL ISSUE

Sonographic evaluation of NET of the small intestine, pancreas and neuroendocrine hepatic metastases.

STANDARD RADIOLOGICAL METHODS

Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), unenhanced ultrasonography.

METHODICAL INNOVATIONS

Contrast-enhanced ultrasound (CEUS).

PERFORMANCE

CEUS supports unenhanced ultrasound in the detection of NET and the differential diagnosis of unclear lesions, and is more sensitive for liver metastases (sensitivity according to the literature, 99% vs. 68%) PRACTICAL RECOMMENDATIONS: CEUS allows initial evaluation of NET and differentiation of benign vs. malignant lesions. Nevertheless, CEUS cannot replace more elaborate imaging modalities like CT or MRI for thorough staging examinations.

Management of Gastrointestinal Neuroendocrine Tumors

Neuroendocrine neoplasms (NENs) are derived from neuroendocrine cell system and can have benign or malignant characteristics. They are rare tumors, but have been increasing in incidence over the past 40 years. Patients with NENs may develop symptoms due to primary tumor invasion, metastasis, or from secretion of hormonally active tumor substances. Multiple imaging modalities are used for diagnosis and staging, including specialty scans such as ¹¹¹In pentetreotide (Octreoscan) and ⁶⁸Gallium-DOTATATE, along with endoscopy, endoscopic ultrasound, and biochemical marker testing. Treatment involves both surgical approach, for both primary and metastatic lesions, as well as medical management for symptom management and disease progression. This article will review the current clinical knowledge regarding the diagnosis, treatment, and prognosis of these fascinating neoplasms and the associated hormonal syndromes.

Demystifying the mesenteric root lesions

OBJECTIVE

The aim of this article is to describe the normal anatomy of the root of the small bowel mesentery (RSBM) as well as the multidetector computed tomography (MDCT) features of the various primary and secondary lesions that affect the RSBM.

RESULTS

The small bowel mesentery attaches the jejunum and ileum to the posterior abdominal wall, the line of attachment forming the RSBM. Several primary as well as secondary lesions involve the RSBM. The RSBM has anatomical contiguity with the mesocolon and other peritoneal ligaments, which forms a route for the spread of infection, neoplasms as well as several other abdominal pathologies. MDCT plays an important role in the evaluation of mesenteric root lesions.

CONCLUSION

Familiarity with the lesions involving the RSBM and their characteristic appearances on MDCT is important in giving thoughtful differential diagnosis and guiding the treating physician in further management.

Genetics and Epigenetics of Gastroenteropancreatic Neuroendocrine Neoplasms

Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs) are heterogeneous regarding site of origin, biological behavior, and malignant potential. There has been a rapid increase in data publication during the last 10 years, mainly driven by high-throughput studies on pancreatic and small intestinal neuroendocrine tumors (NETs). This review summarizes the present knowledge on genetic and epigenetic alterations. We integrated the available information from each compartment to give a pathway-based overview. This provided a summary of the critical alterations sustaining neoplastic cells. It also highlighted similarities and differences across anatomical locations and points that need further investigation. GEP-NENs include well-differentiated NETs and poorly differentiated neuroendocrine carcinomas (NECs). NENs are graded as G1, G2, or G3 based on mitotic count and/or Ki-67 labeling index, NECs are G3 by definition. The distinction between NETs and NECs is also linked to their genetic background, as TP53 and RB1 inactivation in NECs set them apart from NETs. A large number of genetic and epigenetic alterations have been reported. Recurrent changes have been traced back to a reduced number of core pathways, including DNA damage repair, cell cycle regulation, and phosphatidylinositol 3-kinase/mammalian target of rapamycin signaling. In pancreatic tumors, chromatin remodeling/histone methylation and telomere alteration are also affected. However, also owing to the paucity of disease models, further research is necessary to fully integrate and functionalize data on deregulated pathways to recapitulate the large heterogeneity of behaviors displayed by these tumors. This is expected to impact diagnostics, prognostic stratification, and planning of personalized therapy.

Report of metastatic ileal neuroendocrine tumor to the submandibular gland

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The differential diagnosis for neck masses is broad and includes neoplastic, infectious, and anatomic considerations.

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Bronchopulmonary neuroendocrine tumors are known to metastasize to the head and neck.

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This report is the first of ileal neuroendocrine tumor metastasis to the submandibular gland.

Background

Neuroendocrine tumors (NETs) of small intestinal origin are generally slow-growing tumors with a relatively high propensity for metastases to surrounding organs and lymphatic tissue. We present the first case of an ileal NET metastasizing to the submandibular gland in a woman with metastatic carcinoid syndrome.

Case presentation

A 55-year-old female presented with a four-month history of a palpable, left-sided neck mass. The patient had a history of metastatic neuroendocrine tumor of ileal origin, initially treated with primary resection 4.5 years previously, with known subdiaphragmatic metastases to the liver, mesenteric nodes, and peritoneum. Four years following primary resection she developed carcinoid syndrome leading to therapy with radiolabelled metaiodobenzylguanidine (MIBG), as well as telotristat etiprate in the context of a clinical trial due to progressive symptoms. A fine needle aspiration biopsy of the neck mass revealed an immunohistochemical staining pattern consistent with ileal NET. The patient underwent a left level 1b neck dissection and submandibular gland excision. Pathology was consistent with metastastic ileal NET.

Conclusion

We report the first case of ileal NET metastasis to the submandibular gland. Familiarity with the carcinoid syndrome and associated physiology should be maintained as it can affect the head and neck on rare occasions. Maintaining a broad differential is key in diagnosis of undifferentiated neck masses.

Exploration of the Exact Prognostic Significance of Lymphatic Metastasis in Jejunoileal Neuroendocrine Tumors

BACKGROUND

How to evaluate the prognostic significance of lymphatic metastasis in patients with small bowel (jejunoileal) neuroendocrine tumors (SBNETs) is still not conclusive.

METHODS

Data for patients with SBNETs, but without distant metastasis, were retrieved from the Surveillance, Epidemiology, and End Results database. Recursive partitioning analysis (RPA) was used for classification development by combining examined lymph nodes (ELNs) and lymph node ratio (LNR).

RESULTS

Overall, 1925 patient records were retrieved. Patients with N0 and N1 disease (based on the definition of the European Neuroendocrine Tumor Society [ENETS] staging classification) did not have different OS (p = 0.7867), nor did patients with N0, N1 (< 12 positive nodes), and N2 (≥ 12 positive nodes) disease based on the definition of American Joint Committee on Cancer (AJCC) 8th edition staging classification (p = 0.5276). However, Cox regression analysis indicated that both ELNs (hazard ratio [HR] 0.968, 95% confidence interval [CI] 0.949-0.987; p = 0.0013) and LNR (HR 2.288, 95% CI 1.122-3.682; p = 0.0006) were prognostic factors. Using RPA, we combined ELNs and LNR, and patients were reclassified into three groups (group 1: ELNs ≥ 12, any LNR; group 2: ELNs < 12, LNR < 0.35; group 3: ELNs < 12, LNR ≥ 0.35). Survival analysis and multivariate Cox regression showed that groups 1, 2, and 3 had progressively worse survival. Furthermore, we found that ELNs ≥ 12 could remarkably improve patient survival (p < 0.001).

CONCLUSIONS

The current definition of lymphatic metastasis could not help predict patient survival. Our newly proposed classification of lymphatic metastasis is better than the ENETS and AJCC 8th edition staging classifications in evaluating the prognostic significance of lymphatic metastasis in SBNETs. Systematic resection of lymph nodes (≥ 12) could help improve patient survival.

Genetic heterogeneity of primary lesion and metastasis in small intestine neuroendocrine tumors

Data on intratumoral heterogeneity of small intestine neuroendocrine tumors (SI-NETs) and related liver metastasis are limited. The aim of this study was to characterize genetic heterogeneity of 5 patients with SI-NETs. Therefore, formalin-fixed, paraffin-embedded tissue samples of primary and metastatic lesions as well as benign liver of five patients with synchronously metastasized, well differentiated SI-NETs were analyzed with whole exome sequencing. For one patient, chip based 850k whole DNA methylome analysis was performed of primary and metastatic tumor tissue as well as control tissue. Thereby, 156 single nucleotide variants (SNVs) in 150 genes were identified and amount of mutations per sample ranged from 9–34 (mean 22). The degree of common (0–94%) and private mutations per sample was strongly varying (6–100%). In all patients, copy number variations (CNV) were found and the degree of intratumoral heterogeneity of CNVs corresponded to SNV analysis. DNA methylation analysis of a patient without common SNVs revealed a large overlap of common methylated CpG sites. In conclusion, SI-NET primary and metastatic lesions show a highly varying degree of intratumoral heterogeneity. Driver events might not be detectable with exome analysis only, and further comprehensive studies including whole genome and epigenetic analyses are warranted.

Survival outcomes and surgical intervention of small intestinal neuroendocrine tumors: a population based retrospective study

BACKGROUND

Small intestinal neuroendocrine tumors (SiNETs) without distant metastasis typically behave in an indolent manner, but there can be heterogeneity. We aimed to define the survival outcomes and impacts of surgical intervention.

METHODS

A retrospective cohort study was conducted by using data from the Surveillance, Epidemiology, and End Results (SEER) database. Clinicopathologic features were analyzed in 4407 patients between 2000 and 2012. The cancer specific survival (CSS) was calculated by the Kaplan-Meier method. Multivariable Cox regression models with hazard ratios (HRs) were constructed to analyze survival outcomes and risk factors.

RESULTS

The adjusted incidence of early SiNETs is 1.3/100,000. Tumors are most commonly located in the ileum and are small (≤ 2 cm). The 5-year and 10-year CSS rates were 95.0% and 88.5%, respectively. Age > 50 years, large tumor size (> 2cm), poor differentiation, advanced T classification, and absence of surgical treatment were independent predictors of poor survival. Stratified analysis indicated that surgery significantly improved survival in patients that were white (HR, 0.45), > 50 years old (HR, 0.61), had duodenal tumors (HR, 0.43), large tumors (> 2cm) (HR, 0.32), advanced T classification (T3: HR, 0.29; T4: HR, 0.18) or well differentiation (HR, 0.55). There was no significant survival difference between local resection and radical resection (P =0.884).

CONCLUSIONS

Early SiNETs have a favorable prognosis. Surgical resection may improve outcomes, particularly in older patients and those with large tumors. More aggressive resections couldn't improve outcomes.

Patient-Reported Symptom Control of Diarrhea and Flushing in Patients with Neuroendocrine Tumors Treated with Lanreotide Depot/Autogel: Results from a Randomized, Placebo-Controlled, Double-Blind and 32-Week Open-Label Study

BACKGROUND

In the double-blind (DB) ELECT study, lanreotide depot/autogel significantly reduced versus placebo the need for short-acting octreotide for symptomatic carcinoid syndrome (CS) control in neuroendocrine tumor (NET) patients. Here we present patient-reported symptom data during DB and initial open-label (IOL) treatment.

MATERIALS AND METHODS

Adults with NETs and CS history, with/without prior somatostatin analog use, were randomized to 16 weeks' DB lanreotide 120 mg subcutaneous or placebo every 4 weeks, followed by 32 weeks' IOL lanreotide. Patients recorded diarrhea and/or flushing frequency and severity daily by Interactive Voice (Web) Response System for 1 month prior to randomization and throughout the study.

RESULTS

Of 115 patients randomized (n = 59 lanreotide, n = 56 placebo), 56 lanreotide and 45 placebo patients enrolled in the IOL phase. During DB treatment, least square (LS) mean percentages of days with moderate/severe diarrhea and/or flushing were significantly lower for lanreotide (23.4%) versus placebo (35.8%; LS mean difference [95% confidence interval]: -12.4 [-20.73 to -4.07]; p = .004). For DB lanreotide patients, average daily composite (frequency × severity) diarrhea scores improved significantly between DB and IOL treatment (mean difference: -0.71 [-1.20 to -0.22]; p = .005), and remained stable for diarrhea and/or flushing. For DB placebo patients, composite scores for diarrhea, flushing, and diarrhea and/or flushing improved significantly between DB and IOL treatment (mean differences: -1.07 [-1.65 to -0.49]; -1.06 [-1.93 to -0.19]; and -2.13 [-3.35 to -0.91]; all p ≤ .018).

CONCLUSION

Improved diarrhea and flushing control in CS patients during 16-week lanreotide treatment was sustained during maintenance of lanreotide treatment for the 32-week IOL phase (48 weeks total).

IMPLICATIONS FOR PRACTICE

This study prospectively collected daily patient-reported data on diarrhea and flushing from the ELECT trial to evaluate the direct impact of lanreotide depot on patients' relief of carcinoid syndrome symptoms. Treatment with lanreotide depot was associated with significant reductions in the percentages of days patients reported symptoms of diarrhea and flushing, as well as reductions in the frequency and severity of daily symptoms compared with placebo during 16 weeks of double-blind treatment. These improvements were sustained for 32 additional weeks of open-label lanreotide treatment (i.e., through week 48 of treatment), resulting in clinically meaningful, long-term symptom reduction.

Is Multifocality an Indicator of Aggressive Behavior in Small Bowel Neuroendocrine Tumors?

OBJECTIVES

Many patients with small bowel neuroendocrine tumors (SBNETs) have multifocal tumors (MFTs), but the frequency of MFTs has varied widely across SBNET studies. It is also unclear whether patients with MFTs have more advanced disease or worse clinical course than do those with unifocal SBNETs. We set out to determine the frequency of multifocal and unifocal SBNETs and compare clinicopathologic factors, somatostatin receptor 2 expression, and survival.

METHODS

Clinicopathologic variables from 179 patients with surgically managed SBNETs were collected. Statistical comparisons were made using Welch t-test, Wilcoxon test, and Fisher's exact test. Survival was assessed using the Kaplan-Meier method. Somatostatin receptor 2 expression was analyzed by quantitative polymerase chain reaction, and Ki-67 expression by immunohistochemistry.

RESULTS

Multifocal tumors were found in 45% of patients with SBNETs. Clinicopathologic factors such as grade, TNM stage, presence of distant metastases, mean somatostatin receptor 2 expression, success of imaging modalities, and preoperative and postoperative hormone levels were not significantly different between multifocal and unifocal groups. Progression-free survival and overall survival were also not significantly affected by multifocality.

CONCLUSIONS

Clinicopathologic features and survival of patients with MFTs and unifocal tumors are remarkably similar. Although the etiology of MFTs is unclear, patients with MFTs do not have a more aggressive clinical course than patients with unifocal SBNETs.

Medical Therapy of Gastrointestinal Neuroendocrine Tumors

Intestinal neuroendocrine tumors (NETs) constitute a heterogeneous group with duodenal, small intestinal, colonic and rectal NETs. They constitute more than half of all NETs, with the highest frequencies in the rectum, small intestine, and colon. The tumor biology varies with the location of the primary tumor as well as with the grade and staging of the tumor. Small intestinal NETs usually present low proliferation and are treated in the first line with somatostatin analogs according to current guidelines. If progression occurs, one can add interferon alpha or change the treatment to everolimus. Peptide receptor radionuclide therapy (PRRT) with Lutetium¹⁷⁷-DOTATATE can be an option in the future after registration of the compound. Rectal tumors are usually small when they metastasize; they can be treated with somatostatin analogs but more so with PRRT, while another option is of course everolimus. Colonic NETs are more aggressive than the rest of intestinal NETs and will be treated with everolimus, sometimes in combination with somatostatin analogs based on positive scintigraphy. Another option is a cytotoxic agent such as streptozotocin plus 5-fluorouracil (5-FU) or temozolomide plus capecitabine. The most aggressive tumors, i.e. neuroendocrine carcinoma G3, are treated with a platin-based therapy plus etoposide; if they present with a lower proliferation, i.e. <50%, temozolomide plus capecitabine plus bevacizumab can also be attempted. Duodenal NETs are mostly treated similar to pancreatic NETs, either with cytotoxic agents, streptozotocin plus 5-FU, or temozolomide plus capecitabine, or with targeted agents such as everolimus.

A 17-year-old male with a Small Bowel Neuroendocrine Tumor: flushing differential diagnosis

Background

Neuroendocrine tumors (NETs) are heterogeneous neoplasms that originate from cells with a secretory function. Small bowel NETs (SB-NETs) are related to serotonin hypersecretion which causes: flushing, diarrhea, abdominal pain, bronchoconstriction and heart involvement, also known as carcinoid syndrome (CS). CS can be confused with an allergic reaction and thus should be considered as a differential diagnosis in the allergy consult. We present the case of a pediatric patient initially referred under the suspicion of food allergies.

Case presentation

We present the case of a 17-year-old male with evanescent non-pruriginous erythematous lesions- flushing that appeared with food consumption, associated with conjunctival injection, warmth and diaphoresis after the lesions disappeared. He denied abdominal pain, diarrhea, cough or wheezing. The 24-h urinary 5-hydroxyindoleacetic acid (5-HIAA) excretion was elevated. The CT scan showed thickening of the distal ileum and multiple lesions on both hepatic lobules and the colonoscopy revealed a tumor in the ileocecal valve. Hepatic and intestinal biopsies reported a well-differentiated NET of the ileocecal valve with hepatic metastasis. He was started on octreotide and underwent a wide hepatectomy and right hemicolectomy with improvement of symptoms.

Conclusions

NETs can present as carcinoid syndrome (flushing, diarrhea, abdominal pain, wheezing), which constitutes vague symptomatology and represents a challenging diagnosis for physicians. They can be confused with an allergic reaction and the allergist should consider it as a differential diagnosis. Accurate diagnostic tests will help to diagnose NETs earlier and potentially prevent carcinoid heart disease, bowel obstruction, and improve quality of life and mortality in these patients.

Clinicopathological features and prognostic validity of WHO grading classification of SI-NENs

BACKGROUND

The clinicopathological characteristics of small intestinal neuroendocrine neoplasms (SI-NENs) and the prognostic validity of WHO grading classification for SI-NENs are still unknown in Asian patients.

METHODS

277 patients and 8315 patients with SI-NENs were retrieved respectively from eleven Chinese hospitals and Surveillance, Epidemiology, and End Results (SEER) cancer registry. Overall survival was used as the major study outcome. Survival analysis using Kaplan-Meier analysis with log-rank test and cox regression analysis were applied.

RESULTS

Clinicopathological characteristics of SI-NENs were quite different among different races. Duodenum was the predominant tumor site in Chinese patients and Asian/Pacific Islander patients but not in white patients from SEER database. Patients with duodenal NENs tended to have more localized disease than patients with jejunal/ileal NENs which were confirmed by patients from SEER database. Grade 3 or poorly differentiated/undifferentiated tumor were more common and tumor size was significantly larger in ampullary NENs compared with that in non-ampullary duodenal NENs. As for the prognostic validity of WHO grading classification, survival between patients with grade 1 and grade 2 disease was not significantly different. Ki-67 index of 5% might be a better threshold between grade 1 and grade 2 than Ki-67 index of 2% in SI-NENs.

CONCLUSIONS

Our study revealed that the clinicopathological characteristics of SI-NENs among different races were quite different. This might because duodenal NENs was much more common in Chinese patients and Asian/Pacific Islander patients. Duodenal NENs and jejunal/ileal NENs, ampullary and non-ampullary duodenal NENs shared different characteristics. Ki-67 index of 5% might be a better threshold between grade 1 and grade 2 in SI-NENs.

Evolving role of the endoscopist in management of gastrointestinal neuroendocrine tumors

Neuroendocrine tumors (NETs) are uncommon gastrointestinal neoplasms but have been increasingly recognized over the past few decades. Luminal NETs originate from the submucosa of the gastrointestinal tract and careful endoscopic exam is a key for accurate diagnosis. Despite their reputation as indolent tumors with a good prognosis, some NETs may have aggressive features with associated poor long-term survival. Management of NETs requires full understanding of tumor size, depth of invasion, local lymphadenopathy status, and location within the gastrointestinal tract. Staging with endoscopic ultrasound or cross-sectional imaging is important for determining whether endoscopic treatment is feasible. In general, small superficial NETs can be managed by endoscopic mucosal resection and endoscopic submucosal dissection (ESD). In contrast, NETs larger than 2 cm are almost universally treated with surgical resection with lymphadenectomy. For those tumors between 11-20 mm in size, careful evaluation can identify which NETs may be managed with endoscopic resection. The increasing adoption of ESD may improve the results of endoscopic resection for luminal NETs. However, enthusiasm for endoscopic resection must be tempered with respect for the more definitive curative results afforded by surgical treatment with more advanced lesions.

Familial small-intestine carcinoids: Chromosomal alterations and germline inositol polyphosphate multikinase sequencing

BACKGROUND

Familial small-intestine neuroendocrine tumors (SI-NETs) are an exceptional inherited entity. Underlying predisposing mechanisms are unelucidated, but inositol polyphosphate multikinase (IPMK) gene alterations might promote their tumorigenesis.

METHODS

A retrospective-prospective nationwide cohort was constituted, by including patients with proven SI-NETs and at least one relative with the same disease. We performed constitutional and somatic IPMK sequencing, and somatic DNA comparative genomic hybridization (CGH).

RESULTS

We included 17 patients from 8 families, who were characterized by high prevalence (57%) of multiple SI-NETs, and high frequency of distant metastases (82%) and carcinoid syndrome (65%). No IPMK mutation was found in constitutional or tumor DNA. CGH array revealed recurrent chromosome-18 deletions but no alteration in the IPMK region.

CONCLUSION

We report here the first European series of patients with familial SI-NETs. Predisposing mechanisms may not involve the IPMK-encoding sequence or chromosomal region and might not differ from those of sporadic SI-NETs.

Neuroendocrine Tumors

Neuroendocrine tumors are increasingly diagnosed, either incidentally as part of screening processes, or for symptoms, which have commonly been mistaken for other disorders initially. The diagnostic workup to characterize tumor behaviour and prognosis focuses on histologic, anatomic, and functional imaging assessments. Several therapeutic options exist for patients ranging from curative and debulking surgery through to liver-directed therapies and systemic treatments. Multimodal therapies are often required over the patient's disease history. The management paradigm can be complex but should be focused on curative resections and then on controlling symptoms and limiting disease progression. There are several new systemic therapies that have completed phase 3 studies with new compounds being studied in phase 2. Genetic and epigenetic markers may lead to a new era of personalised therapy in the future.

Update on management of midgut neuroendocrine tumors

Midgut neuroendocrine tumors are typically indolent but can be fatal when advanced. They can also cause significant morbidity due to the characteristic carcinoid syndrome. Somatostatin analogs continue to be the mainstay of treatment given their antiproliferative properties, as well as inhibitory effects on hormones that cause carcinoid syndrome. There have been several recent advances in the systemic therapy of these tumors including consolidation of somatostatin analogs as the cornerstone of therapy, completion of pivotal trials with mTOR inhibitors, and the establishment of novel approaches including peptide receptor radionuclide therapy and oral inhibitors of peripheral tryptophan hydroxylase in tumor and symptom control, respectively. In this review article, the recent advances are summarized and an updated approach to management is proposed.

Notch Signaling in Neuroendocrine Tumors

Carcinoids and neuroendocrine tumors (NETs) are a heterogeneous group of tumors that arise from the neuroendocrine cells of the GI tract, endocrine pancreas, and the respiratory system. NETs remain significantly understudied with respect to molecular mechanisms of pathogenesis, particularly the role of cell fate signaling systems such as Notch. The abundance of literature on the Notch pathway is a testament to its complexity in different cellular environments. Notch receptors can function as oncogenes in some contexts and tumor suppressors in others. The genetic heterogeneity of NETs suggests that to fully understand the roles and the potential therapeutic implications of Notch signaling in NETs, a comprehensive analysis of Notch expression patterns and potential roles across all NET subtypes is required.

De-misty-fying the mesentery: an algorithmic approach to neoplastic and non-neoplastic mesenteric abnormalities

Mesenteric abnormalities are often incidentally discovered on cross-sectional imaging performed during daily clinical practice. Findings can range from the vague "misty mesentery" to solid masses, and the possible etiologic causes encompass a wide spectrum of underlying pathologies including infectious, inflammatory, and neoplastic processes. Unfortunately, the clinical and imaging findings are often non-specific and may overlap. This article discusses the various diseases that result in mesenteric abnormalities. It provides a framework to non-invasively differentiate these entities, when possible.

Diagnosis and Management of Hereditary Carcinoids

Carcinoid tumours arise in cells of the diffuse neuroendocrine system and can develop in a number of anatomical sites including the lungs and the gastrointestinal tract. There has been a move away from the use of the term carcinoid tumour to the more appropriate use of neuroendocrine tumour (NET) to highlight the potential for invasion and metastasis associated with some NETs. Although most cases are sporadic, 15-20% of cases are related to a hereditary syndrome, the most common of these being multiple endocrine neoplasia 1 (MEN1). Other hereditary syndromes include the following: von Hippel-Lindau (VHL), neurofibromatosis 1 and tuberous sclerosis complex (TSC), which are all associated with a germline mutation of the associated tumour suppressor gene and an autosomal dominant inheritance pattern. Familial small intestinal NET (SI NET) is a recently described condition which is also inherited in an autosomal dominant manner. There appears to be more than one causative gene; thus far, only the IPMK gene has been identified as a causative germline mutation. This was identified by carrying out whole-exome sequencing of germline and tumour DNA in a family with multiple members diagnosed with SI NET. Identification of NET predisposition genes in other families via these methods will allow the development of dedicated NET gene panels which can be used to screen NET patients and at-risk relatives for hereditary mutations. Close surveillance of at-risk individuals is important to detect NETs early when curative surgery can be offered and the morbidity and mortality of metastatic NETs can be avoided.

Toward a Preoperative Classification of Lymph Node Metastases in Patients with Small Intestinal Neuroendocrine Tumors in the Era of Intestinal-Sparing Surgery

INTRODUCTION

In patients with small intestinal neuroendocrine tumors (siNETs), surgical resection of the primary tumor and associated mesenteric lymph nodes (LNs) is recommended, but is not well standardized and can be risky in patients with superior mesenteric vessel involvement.

OBJECTIVE

We aimed to evaluate the correlation between the length of resected small bowel and the number of removed LNs, and to propose a preoperative morphological classification of siNET-associated LNs.

METHODS

The records of patients operated on for siNETs at two expert centers between August 2005 and November 2013 were analyzed. Two specialist radiologists reviewed the preoperative imaging and classified mesenteric LNs into five stages according to their proximity to the trunk and/or branches of the superior mesenteric artery.

RESULTS

72 patients were included. The mean number of removed LNs was 12 ± 15 and the length of removed small intestine was 53 ± 43 cm. No correlation existed between the length of small bowel resection and the number of removed LNs. Overall, 9 (12%), 13 (18%), 36 (50%), 14 (19%) and 0 patients were classified into LN stages 0, I, II, III and IV. The correlation rate between the two observers was 0.98. Patients with LN stage III (hardly resectable) had more removed LNs than those with LN stages 0, I or II (easily removable).

CONCLUSION

Optimal lymphadenectomy is not always associated with extended small bowel resection. In the era of small bowel-sparing surgery, the preoperative classification of mesenteric LNs could help to standardize the surgical management of patients with siNETs.

Most small bowel cancers are revealed by a complication

Objective

To characterize the pattern of primary small bowel cancers in a tertiary East-European hospital.

Methods

A retrospective study of patients with small bowel cancers admitted to a tertiary emergency center, over the past 15 years.

Results

There were 57 patients with small bowel cancer, representing 0.039% of admissions and 0.059% of laparotomies. There were 37 (64.9%) men, mean age of 58 years; and 72 years for females. Out of 57 patients, 48 (84.2%) were admitted due to an emergency situation: obstruction in 21 (38.9%), perforation in 17 (31.5%), upper gastrointestinal bleeding in 8 (14.8%), and lower gastrointestinal bleeding in 2 (3.7%). There were 10 (17.5%) duodenal tumors, 21 (36.8%) jejunal tumors and 26 (45.6%) ileal tumors. The most frequent neoplasms were gastrointestinal stromal tumor in 24 patients (42.1%), adenocarcinoma in 19 (33.3%), lymphoma in 8 (14%), and carcinoids in 2 (3.5%). The prevalence of duodenal adenocarcinoma was 14.55 times greater than that of the small bowel, and the prevalence of duodenal stromal tumors was 1.818 time greater than that of the small bowel. Obstruction was the complication in adenocarcinoma in 57.9% of cases, and perforation was the major local complication (47.8%) in stromal tumors.

Conclusion

Primary small bowel cancers are usually diagnosed at advanced stages, and revealed by a local complication of the tumor. Their surgical management in emergency setting is associated to significant morbidity and mortality rates.

DNA methylation profiles distinguish different subtypes of gastroenteropancreatic neuroendocrine tumors

AIM

Most studies have considered gastroenteropancreatic neuroendocrine tumors (GEP-NETs) as a homogenous group of samples or distinguish only gastrointestinal from pancreatic endocrine tumors. This article investigates if DNA methylation patterns could distinguish subtypes of GEP-NETs.

MATERIALS & METHODS

The DNA methylation level of 807 cancer-related genes was investigated in insulinomas, gastrinomas, non-functioning pancreatic endocrine tumors and small intestine endocrine tumors.

RESULTS

DNA methylation patterns were found to be tumor type specific for each of the pancreatic tumor subtypes and identified two distinct methylation-based groups in small intestine endocrine tumors. Differences of DNA methylation levels were validated by pyrosequencing for 20 candidate genes and correlated with differences at the transcriptional level for four candidate genes.

CONCLUSION

The heterogeneity of DNA methylation patterns in the different subtypes of gastroenteropancreatic neuroendocrine tumors suggests different underlying pathways and, therefore, these tumors should be considered as distinct entities in molecular and clinical studies.

[Intestinal carcinoid tumour: Case report]

BACKGROUND

Carcinoid of the small intestine, is a well-differentiated neuroendocrine tumor that rarely presents with clinical signs. This tumour can be associated with other conditions, such as inflammatory bowel disease, presenting a wide range of symptoms. In some cases they have an aggressive and highly symptomatic behaviour; thus, clinical suspicion must be high to make an early diagnosis.

CLINICAL CASE

A 60 year-old male patient with Crohn's disease and gastrointestinal symptoms attributed to this disease within the last year. He presented with intestinal obstruction initially treated with conservative management with no improvement. Exploratory laparotomy was performed finding a mesenteric tumour that caused the bowel obstruction. Bowel resection with primary anastomosis was performed. The pathology report showed an intestinal carcinoid tumour with lymph node metastases. The patient recovered well, and was discharged without complications to continue medical treatment and follow-up by the Oncology department.

CONCLUSION

In almost 42% of the cases, the most common site of carcinoid tumours is the small intestine, and of these, 41% are presented as locoregional disease. Patients with Crohn's disease present a higher incidence. In these cases, the most common presentation is an acute intestinal obstruction (90%). Surgery is usually curative, and follow up is important as the symptoms of Crohn's disease can hide any recurrence.

Primary small-bowel malignancy: update in tumor biology, markers, and management strategies

PURPOSE

Primary small-bowel malignancies (SBM) are rare tumors but their incidence is rising. An estimated 9160 new cases and 1210 deaths due to SBM may occur in the USA in 2014. We review advances made in tumor biology, immunohistochemistry, and discuss treatment strategies for these malignancies.

METHODS

Relevant articles from PubMed/Medline and Embase searches were collected using the phrases "small-bowel adenocarcinoma, gastrointestinal carcinoids, gastrointestinal stromal tumors, small-bowel leiomyosarcoma, and small-bowel lymphoma".

RESULTS

Advances in imaging techniques such as wireless capsule endoscopy, CT and MRI enterography, and endoscopy (balloon enteroscopy) along with discovery of molecular markers such as c-kit and PDGFRA for GIST tumors have improved our ability to diagnose, localize, and treat these patients. Early detection and surgical resection offers the best chance for long-term survival in all tumors except bowel lymphoma where chemotherapy plays the main role. Adjuvant therapy with imatinib has improved overall survival for GIST tumors, somatostatin analogs have improved symptoms and also inhibited tumor growth and stabilized metastatic disease in carcinoid disease, but chemotherapy has not improved survival for adenocarcinoma.

CONCLUSIONS

Recent advances in molecular characterization holds promise in novel targeted therapies. Currently ongoing trials are exploring efficacy of targeted therapies and role of adjuvant therapy for adenocarcinoma and results are awaited. Early detection and aggressive surgical therapy for all localized tumors and lymph node sampling particularly for adenocarcinoma remains the main treatment modality.

A Hereditary Form of Small Intestinal Carcinoid Associated With a Germline Mutation in Inositol Polyphosphate Multikinase

BACKGROUND & AIMS

Small intestinal carcinoids are rare and difficult to diagnose and patients often present with advanced incurable disease. Although the disease occurs sporadically, there have been reports of family clusters. Hereditary small intestinal carcinoid has not been recognized and genetic factors have not been identified. We performed a genetic analysis of families with small intestinal carcinoids to establish a hereditary basis and find genes that might cause this cancer.

METHODS

We performed a prospective study of 33 families with at least 2 cases of small intestinal carcinoids. Affected members were characterized clinically and asymptomatic relatives were screened and underwent exploratory laparotomy for suspected tumors. Disease-associated mutations were sought using linkage analysis, whole-exome sequencing, and copy number analyses of germline and tumor DNA collected from members of a single large family. We assessed expression of mutant protein, protein activity, and regulation of apoptosis and senescence in lymphoblasts derived from the cases.

RESULTS

Familial and sporadic carcinoids are clinically indistinguishable except for the multiple synchronous primary tumors observed in most familial cases. Nearly 34% of asymptomatic relatives older than age 50 were found to have occult tumors; the tumors were cleared surgically from 87% of these individuals (20 of 23). Linkage analysis and whole-exome sequencing identified a germline 4-bp deletion in the gene inositol polyphosphate multikinase (IPMK), which truncates the protein. This mutation was detected in all 11 individuals with small intestinal carcinoids and in 17 of 35 family members whose carcinoid status was unknown. Mutant IPMK had reduced kinase activity and nuclear localization, compared with the full-length protein. This reduced activation of p53 and increased cell survival.

CONCLUSIONS

We found that small intestinal carcinoids can occur as an inherited autosomal-dominant disease. The familial form is characterized by multiple synchronous primary tumors, which might account for 22%-35% of cases previously considered sporadic. Relatives of patients with familial carcinoids should be screened to detect curable early stage disease. IPMK haploinsufficiency promotes carcinoid tumorigenesis.

Jejunal Intussusception: A Rare Presentation of Carcinoid Tumor

A 55-year-old male presented to the emergency department with sudden onset of diffuse abdominal pain for one day. Physical examination was remarkable for tenderness in the umbilical region. A CT scan of the abdomen showed intussusception involving the jejunum without any mass. The patient then underwent an exploratory laparotomy. During surgery, the distal jejunum was intussuscepted with mesenteric lymphadenopathy. Liver showed nodular deposits in both lobes of the liver. The involved small bowel segment was resected with primary anastomosis and liver was biopsied. Pathological examination showed multifocal deposits of well-differentiated carcinoids in the jejunum. The liver and mesenteric deposits were positive for metastatic carcinoid. Patient recovered well without any complications.

A review on management discussions of small intestinal neuroendocrine tumors ‘midgut carcinoids’

European Neuroendocrine Tumor Society staging, together with the Ki67 grading system, has appeared as superior for classification of neuroendocrine tumors (NET). The management of small intestinal NET (SI-NET) has been overall controversial. Mesenteric metastases occur also with the smallest SI-NET, and the majority of patients risk to ultimately progress with liver metastases. 68Gallium (somatostatin receptor)/PET/CT has appeared as most sensitive for imaging, and fluorodeoxyglucose-PET is recommended to identify lesions with high proliferation. Our treatment policy for SI-NET is to initiate somatostatin analog treatment, and in order to prevent abdominal complications we recommend early intestinal resection for removal of primary tumors and clearance of lymph node metastases. Liver metastases are liberally treated by resection (or ablation), as this can efficiently palliate carcinoid syndrome-associated symptoms.

Liver metastases of small intestine neuroendocrine tumors: Ki-67 heterogeneity and World Health Organization grade discordance with primary tumors

OBJECTIVES

We examined Ki-67 heterogeneity within single and between synchronous liver metastases of small intestine neuroendocrine tumors.

METHODS

There were 27 patients (10 men and 17 women) with two or more liver metastases. The Ki-67 index was used to classify the tumors into World Health Organization grade 1, 2, or 3. The association between Ki-67 heterogeneity and tumor size of liver metastases was analyzed. Correlation of tumor grade with patient survival was also evaluated.

RESULTS

Primary tumors from 20 patients were graded, including 17 grade 1 and three grade 2. A total of 188 liver metastases were resected, including 122 (65%) grade 1, 47 (25%) grade 2, and 19 (10%) grade 3. The highest tumor grade was grade 1 in 10 (37%), grade 2 in nine (33%), and grade 3 in eight (30%) patients. Patients with one or more grade 3 liver lesions had a shorter progression-free survival compared with those with grade 1/2 tumors (P < .001). A positive association was found between tumor size and Ki-67 index (P = .04), as well as between tumor size and intratumoral Ki-67 heterogeneity (P < .001).

CONCLUSIONS

Intratumoral and intertumoral Ki-67 heterogeneity is common and positively correlated with tumor size. The presence of one or more grade 3 liver lesions predicts a worse prognosis.

Rare diseases in clinical endocrinology: a taxonomic classification system

PURPOSE

Rare endocrine-metabolic diseases (REMD) represent an important area in the field of medicine and pharmacology. The rare diseases of interest to endocrinologists involve all fields of endocrinology, including rare diseases of the pituitary, thyroid and adrenal glands, paraganglia, ovary and testis, disorders of bone and mineral metabolism, energy and lipid metabolism, water metabolism, and syndromes with possible involvement of multiple endocrine glands, and neuroendocrine tumors. Taking advantage of the constitution of a study group on REMD within the Italian Society of Endocrinology, consisting of basic and clinical scientists, a document on the taxonomy of REMD has been produced.

METHODS AND RESULTS

This document has been designed to include mainly REMD manifesting or persisting into adulthood. The taxonomy of REMD of the adult comprises a total of 166 main disorders, 338 including all variants and subtypes, described into 11 tables.

CONCLUSIONS

This report provides a complete taxonomy to classify REMD of the adult. In the future, the creation of registries of rare endocrine diseases to collect data on cohorts of patients and the development of common and standardized diagnostic and therapeutic pathways for each rare endocrine disease is advisable. This will help planning and performing intervention studies in larger groups of patients to prove the efficacy, effectiveness, and safety of a specific treatment.

Delayed recurrence of atypical pulmonary carcinoid cluster: a rare occurrence

Carcinoid is one of the most common tumors of the gastrointestinal tract followed by the tracheobronchial tree. Bronchial carcinoid compromises 20% of total carcinoid and accounts for 1–5% of pulmonary malignancies. Carcinoid can be typical or atypical, with atypical carcinoid compromises 10% of the carcinoid tumors. Carcinoid usually presents as peripheral lung lesion or solitary endobronchial abnormality. Rarely it can present as multiple endobronchial lesion. We hereby present a rare case of an elderly gentleman who had undergone resection of right middle and lower lobe of lung for atypical carcinoid. Seven years later he presented with cough. CT scan of chest revealed right hilar mass. Flexible bronchoscopy revealed numerous endobronchial polypoid lesions in the tracheobronchial tree. Recurrent atypical carcinoid was then confirmed on biopsy.

Significance of biochemical markers in the diagnosis of neuroendocrine tumours and in the follow-up of patients

Circulating markers of neuroendocrine tumours are useful tools in the diagnosis of these tumours. Laboratory tests for general biomarkers have acceptable sensitivity for the recognition of neuroendocrine tumours as these biologically active proteins are typically synthesized by all types of neuroendocrine cells. Measurement of chromogranin A is widely used not only in the diagnosis of neuroendocrine tumours but it may predict the prognosis of the diseases and the effect of the antitumor therapy. It is also a useful tool for the detection of residual tumours. Neurendocrine tumours represent a heterogeneous group of tumours with the ability to secrete several hormones and, therefore, measurement of these hormones can also serve as neuroendocrine cell type-specific markers in routine clinical practice. In this review the authors summarize the significance of tumour markers in the diagnosis of neuroendocrine tumours as well as in the management and follow-up of patients with this disease. Orv. Hetil., 2014, 155(45), 1775–1782.