Carcinoid syndrome: update on the pathophysiology and treatment

The radiologic spectrum of neuroendocrine tumors in emergent care

Neuroendocrine tumors (NETs) are a diverse group of neoplasms whose prevalence is increasing globally, primarily due to advancements in diagnostic techniques. NETs arise from cells of the diffuse endocrine system and can occur in various locations, with the gastrointestinal tract being the most common. Their diverse clinical presentations, which range from asymptomatic to severe hormone-induced syndromes, pose significant diagnostic challenges. In emergency care, prompt recognition and management of complications such as bowel obstruction, ischemic events, hormonal crises, and metastases are critical. This review discusses the radiologic spectrum of NETs in emergent care, emphasizing the role of imaging in timely diagnosis and intervention.

Functioning neuroendocrine tumors (NET): Minimum requirements for a NET specialist

INTRODUCTION AND AIMS

Functioning neuroendocrine tumors (f-NETs) represent a minority of all NETs, however their management is challenging due to the impact on patients' survival and quality of life. In addition to f-NETs, paraneoplastic syndromes (PNS) are due to substances that are not related to the primary anatomical site, they can develop in different phases of NETs evolution, and might complicate the patient's clinical course. Dedicated guidelines are still scanty. We aim to review available literature on f-NETs to propose a useful tool for clinicians in order to improve the diagnostic process and the management.

METHODS

Narrative review focused on f-NETs.

RESULTS

The most common f-NETs include insulinomas, gastrinomas and carcinoid syndrome (CS)- associated NETs. Symptoms related to hormone production may overlap with other common endocrine and gastrointestinal disorders, highlighting the pivotal role of multidisciplinary management. Somatostatin analogs (SSAs) represent the gold standard first-line treatment of most f-NETs, often followed by or combined with other treatments (surgery, liver-directed therapies, targeted therapies, peptide receptor radionuclide therapy). Paraneoplastic syndromes can develop in different phases of NET evolution and might complicate the patient's clinical course and response to therapy.

CONCLUSIONS

The management of hormonal syndromes is challenging and must be based on the multidisciplinary approach. Herein, we pointed out the minimal requirements for a NET specialist in the diagnosis and treatment of f-NETs. Efforts should be made to improve the awareness of functioning forms, to understand their pathogenesis and to improve their management.

Neuroendocrine Carcinoid Lung Tumor: A Case Series of an Indolent Tumor

Neuroendocrine tumors (NETs) of the lung are infrequently encountered tumors, constituting a small subset of pulmonary neoplasms. The lung is the second most common site of carcinoid tumors. Most patients experience vague symptoms for many years, making them fairly difficult to diagnose. This case series presents three unique and challenging cases of pulmonary neuroendocrine tumors. Case 1 is a 55-year-old female with a 6-month history of progressive dyspnea and noted to have a lung mass blocking the left main bronchus. The patient underwent bronchoscopy with tissue diagnosis and ultimately needed thoracotomy and left-sided pneumonectomy. Case 2 is a 61-year-old female with a chronic cough for several years who was seen to have a right lung mass, underwent a bronchoscopy showing a Carcinoid tumor, and was taken for a right lower lobe lobectomy. Case 3 is a 75-year-old female who was seen to have a right hilar mass as an incidental finding on CT imaging. The patient underwent bronchoscopy with the biopsy proving carcinoid tumor. The patient had multiple co-morbidities, was not deemed to be a surgical candidate, and was referred for radiation therapy. The patients in the case series presented with nonspecific respiratory symptoms, leading to diagnostic investigations including imaging studies and bronchoscopy evaluation. Histopathological examination revealed a well-differentiated neuroendocrine tumor with positive immunohistochemical staining for neuroendocrine markers. Subsequent staging investigations confirmed localized disease without distant metastasis. Multidisciplinary collaboration involving pulmonologists, oncologists, radiation oncologists, and surgeons played a pivotal role in determining the optimal therapeutic approach. These patients underwent surgical resection, and postoperative pathology confirmed clear margins. Adjuvant therapy was considered based on the tumor characteristics and the overall risk of recurrence.

A case of carcinoid syndrome after CT guided lung biopsy of a neuroendocrine tumor

Carcinoid tumors of the lung are an uncommon malignancy that can rarely lead to carcinoid syndrome. Carcinoid tumors represent less than 1% of all lung cancers. This case describes a rare presentation in which a previously asymptomatic woman began to experience tachycardia, shortness of breath, and anxiety after biopsy of a pulmonary carcinoid tumor. Chest CT, histology, and clinical course supported the diagnosis and the patient's symptoms quickly resolved with medication. Ultimately, surgical removal of the tumor led to complete resolution of symptoms.

Agonists, Antagonists and Receptors of Somatostatin: Pathophysiological and Therapeutical Implications in Neoplasias

Somatostatin is a peptide that plays a variety of roles such as neurotransmitter and endocrine regulator; its actions as a cell regulator in various tissues of the human body are represented mainly by inhibitory effects, and it shows potent activity despite its physiological low concentrations. Somatostatin binds to specific receptors, called somatostatin receptors (SSTRs), which have different tissue distributions and associated signaling pathways. The expression of SSTRs can be altered in various conditions, including tumors; therefore, they can be used as biomarkers for cancer cell susceptibility to certain pharmacological agents and can provide prognostic information regarding disease evolution. Moreover, based on the affinity of somatostatin analogs for the different types of SSTRs, the therapeutic range includes conditions such as tumors, acromegaly, post-prandial hypotension, hyperinsulinism, and many more. On the other hand, a number of somatostatin antagonists may prove useful in certain medical settings, based on their differential affinity for SSTRs. The aim of this review is to present in detail the principal characteristics of all five SSTRs and to provide an overview of the associated therapeutic potential in neoplasias.

Carcinoid Heart Disease

Carcinoid heart disease (CHD) is a rare cardiac complication that occurs most commonly in patients with advanced neuroendocrine tumors and is a known sequela of carcinoid syndrome. Neuroendocrine tumors most widely associated with CHD include tumors in the small bowel, followed by lung, large bowel, pancreatic, appendiceal, and ovarian neoplasms. Carcinoid syndrome is a paraneoplastic syndrome caused by the release of serotonin and other substances from neuroendocrine tumors. It results in a spectrum of symptoms, including diarrhea, flushing, bronchospasm, and symptoms of congestive heart failure. Without treatment and for patients with advanced heart failure, the prognosis of CHD can be less than a year. Management of CHD is often challenging as patients typically present late, and the disease can progress rapidly. Therefore, optimal management of these patients requires close collaboration among various specialties to quantify disease burden, delay the progression of valvular disease, and determine the most effective surgical and medical management strategies depending on the cardiac manifestations to improve quality of life and reduce mortality. This involves a collaborative team, including cardiology and oncology, and often involves many other disciplines, including hepatobiliary and cardiovascular surgeons, endocrinologists, anesthesiologists, and gastroenterologists.

Imaging Update for Hereditary Abdominopelvic Neuroendocrine Neoplasms

ABSTRACT

Neuroendocrine neoplasms have shown a linear increase in incidence and prevalence in recent decades, primarily due to improved cross-sectional imaging, expanded use of endoscopic procedures, and advanced genetic analysis. However, diagnosis of hereditary neuroendocrine tumors is still challenging because of heterogeneity in their presentation, the variety of tumor locations, and multiple associated syndromes. Radiologists should be familiar with the spectrum of these tumors and associated hereditary syndromes. Furthermore, as the assessment of multiple tumor elements such as morphology, biochemical markers, and presence of metastatic disease are essential for the treatment plan, conventional anatomic and functional imaging methods are fundamental in managing and surveilling these cases. Our article illustrates the role of different cross-sectional imaging modalities in diagnosing and managing various hereditary abdominopelvic neuroendocrine tumors.

What Is Carcinoid Syndrome? A Critical Appraisal of Its Proposed Mediators

Carcinoid syndrome (CS) is a debilitating disease that affects approximately 20% of patients with neuroendocrine neoplasms (NEN). Due to the increasing incidence and improved overall survival of patients with NEN over recent decades, patients are increasingly suffering from chronic and refractory CS symptoms. At present, symptom control is hampered by an incomplete understanding of the pathophysiology of this syndrome. This systematic review is the first to critically appraise the available evidence for the various hormonal mediators considered to play a causative role in CS. Overall, evidence for the putative mediators of CS was scarce and often of poor quality. Based on the available literature, data are only sufficient to agree on the role of serotonin as a mediator of CS-associated diarrhea and fibrosis. A direct role for tachykinins and an indirect role of catecholamines in the pathogenesis of CS is suggested by several studies. Currently, there is insufficient evidence to link histamine, bradykinin, kallikrein, prostaglandins, or motilin to CS. To summarize, available literature only sufficiently appoints serotonin and suggests a role for tachykinins and catecholamines as mediators of CS, with insufficient evidence for other putative mediators. Descriptions of CS should be revised to focus on these proven hormonal associations to be more accurate, and further research is needed into other potential mediators.

Liver-Directed Locoregional Therapies for Neuroendocrine Liver Metastases: Recent Advances and Management

Neuroendocrine tumors (NETs) are a heterogeneous class of cancers, predominately occurring in the gastroenteropancreatic system, which pose a growing health concern with a significant rise in incidence over the past four decades. Emerging from neuroendocrine cells, these tumors often elicit paraneoplastic syndromes such as carcinoid syndrome, which can manifest as a constellation of symptoms significantly impacting patients' quality of life. The prognosis of NETs is influenced by their tendency for metastasis, especially in cases involving the liver, where the estimated 5-year survival is between 20 and 40%. Although surgical resection remains the preferred curative option, challenges emerge in cases of neuroendocrine tumors with liver metastasis (NELM) with multifocal lobar involvement, and many patients may not meet the criteria for surgery. Thus, minimally invasive and non-surgical treatments, such as locoregional therapies, have surfaced. Overall, these approaches aim to prioritize symptom relief and aid in overall tumor control. This review examines locoregional therapies, encompassing catheter-driven procedures, ablative techniques, and radioembolization therapies. These interventions play a pivotal role in enhancing progression-free survival and managing hormonal symptoms, contributing to the dynamic landscape of evolving NELM treatment. This review meticulously explores each modality, presenting the current state of the literature on their utilization and efficacy in addressing NELM.

Normalization of Prediabetic Hemoglobin A1c (HbA1c) Levels After the Surgical Removal of a Serotonin-Secreting Neuroendocrine Tumor

Neuroendocrine tumors (NETs) are rare. When present, they often produce serotonin and are called carcinoids. Serotonin-secreting NETs can present with or without carcinoid syndrome. Although the idea of serotonin-secreting NETs potentially altering glucose metabolism is not new, data around this issue has been scarce, with only a few limited studies and case reports. We present a case where a female patient's prediabetic hemoglobin A1C levels normalized after removing serotonin-secreting NET. Before removal, the patient had locally metastatic carcinoid and serotonin-related intractable diarrhea but did not exhibit any other sign of carcinoid syndrome, including flushing, which is considered a hallmark. Therefore, in suggestive clinical contexts, this case points to the possibility of impaired glucose tolerance being an early clinical sign of carcinoid that could aid in serotonin-secreting NET diagnosis before it manifests as overt carcinoid syndrome.

Nodular image in the appendix observed on ultrasound: endometriosis or neuroendocrine neoplasia?

Objective

To evaluate the association between clinical and imaging with surgical and pathological findings in patients with suspected neuroendocrine tumor of appendix and/or appendix endometriosis.

Methods

Retrospective descriptive study conducted at the Teaching and Research Institute of Hospital Israelita Albert Einstein, in which medical records and databases of patients with suspected neuroendocrine tumor of appendix and/or endometriosis of appendix were analyzed by imaging.

Results

Twenty-eight patients were included, all of which had some type of appendix alteration on the ultrasound examination. The pathological outcome of the appendix found 25 (89.3%) lesions compatible with endometriosis and three (10.7%) neuroendocrine tumors. The clinical findings of imaging and surgery were compared with the result of pathological anatomy by means of relative frequency.

Conclusion

It was possible to observe a higher prevalence of appendix endometriosis when the patient presented more intense pain symptoms. The image observed on ultrasound obtained a high positive predictive value for appendicular endometriosis.

The skin as a window to the gut: A case of carcinoid syndrome

Neuroendocrine tumors (NETs) are a group of uncommon neoplasms derived from enterochromaffin or Kulchitsky cells (that secrete serotonin or other molecules into the bloodstream), which can manifest with symptoms of hormonal overproduction, namely carcinoid syndrome (CS). This can be the presenting feature in patients with advanced disease. We report the case of a 66-year-old woman presenting with chronic diarrhea, facial venous telangiectasia and elevated urinary 5-hydrocyindoleacetic acid levels. A 68-Ga DOTATOC PET/CT scan revealed an ileal mass and lesions consistent with liver, ovary and bone metastasis. A liver biopsy confirmed the diagnosis of well-differentiated NET G1. Therapy with somatostatin analogs achieved symptom control, but the liver disease progressed and the patient passed away after 2 years of follow-up. The challenge of diagnosing CS resides in its heterogeneous manifestations, which may range from mild to life-threatening conditions. In this case, the cutaneous findings of venous telangiectasia strongly pointed to the correct diagnosis. Treatment can also be difficult due to refractory symptoms and inevitable progression of disease, highlighting the importance of early detection and thorough disease staging.

The cause-and-effect relationship between gut microbiota abundance and carcinoid syndrome: a bidirectional Mendelian randomization study

Objective

Carcinoid syndrome (CS) commonly results from neuroendocrine tumors. While active substances are recognized as the main causes of the typical symptoms such as diarrhea and skin flush, the cause-and-effect relationship between gut microbiota abundance and CS remains unclear.

Methods

The Single Nucleotide Polymorphisms (SNPs) related to gut microbiota abundance and CS were obtained from the GWAS summary data. The inverse variance weighted (IVW) method was used to assess the causal relationship between gut microbiota abundance and CS. Additionally, the MR-Egger, Weighted Median model, and Weighted model were employed as supplementary approaches. The heterogeneity function of the TwoSampleMR package was utilized to assess whether SNPs exhibit heterogeneity. The Egger intercept and Presso test were used to assess whether SNPs exhibit pleiotropy. The Leave-One-Out test was employed to evaluate the sensitivity of SNPs. The Steiger test was utilized to examine whether SNPs have a reverse causal relationship. A bidirectional mendelian randomization (MR) study was conducted to elucidate the inferred cause-and-effect relationship between gut microbiota abundance and CS.

Results

The IVW results indicated a causal relationship between 6 gut microbiota taxa and CS. Among the 6 gut microbiota taxa, the genus Anaerofilum (IVW OR: 0.3606, 95%CI: 0.1554-0.8367, p-value: 0.0175) exhibited a protective effect against CS. On the other hand, the family Coriobacteriaceae (IVW OR: 3.4572, 95%CI: 1.0571-11.3066, p-value: 0.0402), the genus Enterorhabdus (IVW OR: 4.2496, 95%CI: 1.3314-13.5640, p-value: 0.0146), the genus Ruminiclostridium6 (IVW OR: 4.0116, 95%CI: 1.2711-12.6604, p-value: 0.0178), the genus Veillonella (IVW OR: 3.7023, 95%CI: 1.0155-13.4980, p-value: 0.0473) and genus Holdemanella (IVW OR: 2.2400, 95%CI: 1.0376-4.8358, p-value: 0.0400) demonstrated a detrimental effect on CS. The CS was not found to have a reverse causal relationship with the above 6 gut microbiota taxa.

Conclusion

Six microbiota taxa were found to have a causal relationship with CS, and further randomized controlled trials are needed for verification.

Structure-Based Design of Xanthine-Imidazopyridines and -Imidazothiazoles as Highly Potent and In Vivo Efficacious Tryptophan Hydroxylase Inhibitors

Tryptophan hydroxylases catalyze the first and rate-limiting step in the biosynthesis of serotonin, a well-known neurotransmitter that plays an important role in multiple physiological functions. A reduction of serotonin levels, especially in the brain, can cause dysregulation leading to depression or insomnia. In contrast, overproduction of peripheral serotonin is associated with symptoms like carcinoid syndrome and pulmonary arterial hypertension. Recently, we developed a class of TPH inhibitors based on xanthine-benzimidazoles, characterized by a tripartite-binding mode spanning the binding sites of the cosubstrate pterin and the substrate tryptophan and by chelation of the catalytic iron ion. Herein, we describe the structure-based development of a second generation of xanthine-imidiazopyridines and -imidazothiazoles designed to inhibit TPH1 in the periphery while preventing the interaction with TPH2 in the brain. Lead compound 32 (TPT-004) shows superior pharmacokinetic and pharmacodynamic properties as well as efficacy in preclinical models of peripheral serotonin attenuation and colorectal tumor growth.

NT-proBNP as a neuroendocrine tumor biomarker: beyond heart failure

Introduction

Neuroendocrine tumors (NETs) are rare neoplasms that occur in various locations throughout the body. Despite their usually benign character, they might manifest with distant metastases. N-terminal prohormone of brain natriuretic peptide (NT-proBNP) has previously been described as a useful biomarker in diagnosing carcinoid heart disease (CHD), a common advanced NETs manifestation. We observed plasma concentrations of NT-proBNP in metastatic midgut NETs over a 4-year period.

Objectives

We aimed to explore NT-proBNP concentrations in states of varying levels of cell proliferation and disease status. Our goal was to investigate NT-proBNP's role in predicting disease progression in relation to previous research and up-to-date scientific guidelines.

Patients and methods

We performed a retrospective multivariate analysis of NT-proBNP concentrations in 41 midgut NETs patients treated with somatostatin analogs, all with liver metastases. NT-proBNP concentrations were measured in every patient across 16 evenly distanced time points over a 48-month period and were compared to variables such as sex, age, grading, Ki-67, primary tumor location, and CT findings.

Results

NT-proBNP concentrations correlated positively with higher liver tumor burden, higher grading, high Ki-67 levels, and with progressive disease in CT. There were no differences in NT-proBNP levels with regard to primary location (ileum vs jejunum), sex, and age.

Conclusion

We conclude that NT-proBNP is a useful analyte for monitoring NETs progression, due to its increased concentration in scenarios implying increased cellular proliferation. These long-term follow-up results align with previous findings and suggest an additional role for NT-proBNP in diagnostic algorithms, beyond a CHD biomarker.

Carcinoid syndrome caused by a pulmonary carcinoid mimics intestinal manifestations of ulcerative colitis: A case report

BACKGROUND

Pulmonary carcinoids are rare, low-grade malignant tumors characterized by neuroendocrine differentiation and relatively indolent clinical behavior. Most cases present as a slow-growing polypoidal mass in the major bronchi leading to hemoptysis and pulmonary infection due to blockage of the distal bronchi. Carcinoid syndrome is a paraneoplastic syndrome caused by the systemic release of vasoactive substances that presents in 5% of patients with neuroendocrine tumors. Due to such nonspecific presentation, most patients are misdiagnosed or diagnosed late and may receive several courses of antibiotics to treat recurrent pneumonia before the tumor is diagnosed.

CASE SUMMARY

We report the case of a 48-year-old male who presented with cough, dyspnea, a history of recurrent pneumonitis, and therapy-refractory ulcerative colitis that completely subsided after the resection of a pulmonary carcinoid.

CONCLUSION

We report and emphasize pulmonary carcinoid as a differential diagnosis in patients with nonresponding inflammatory bowel diseases and recurrent pneumonia.

Health care resource use and costs among patients with carcinoid syndrome in France: Analysis of the National Health Insurance Database

OBJECTIVES

Carcinoid syndrome (CS) develops in approximately 20% of patients with neuroendocrine tumours (NET). This study described healthcare resource utilization and its associated costs among patients with NET and CS, using the French national health care data system.

METHODS

Patients were included if they had a hospital stay associated with the code E34.0 "CS" and at least one delivery of a somatostatin analogue (SSA) between 01/01/2012 and 31/12/2016. The end of the analysis was either 31/12/2017 or the date of death, whichever occurred first. Mean overall costs were described by item of expenditure and by periods.

RESULTS

646 patients were included: 64yo, 55% men, 64% and 15% had NET from the small-intestine or lung, respectively. Among them, 309 patients were incident and 271 died during the study period. Mean overall cost per person per month (PPPM) was €2,892: €3,273 for the first year following diagnosis, €2,574 in "middle-years" and €5,039 within the year preceding death. The two most costly expenditure items were drugs (€1,695 PPPM) and hospital stays (€870 PPPM).

CONCLUSION

The first year following diagnosis and the year preceding death are the two periods representing the highest costs for CS care in France. Successful disease management may contribute to lower costs in the intermediate period.

Exploring the Link Between Pancreatic Neuroendocrine Tumors and Depression: A Case Study

This case probes the potential temporal relationship between pancreatic neuroendocrine tumor (PNET) and depression. This patient has chronic symptoms of depression with no formal diagnosis until within a year of doctors suspecting her diagnosis of pancreatic cancer. An excisional biopsy confirmed a grade 1 neuroendocrine tumor (NET) in the pancreas, and postoperative psychiatric consultation confirmed continued elevated depression. This report presents an illustrative example of the ongoing research questions surrounding the relationship between the timing of a depression diagnosis and a PNET diagnosis. The depression-before-diagnosis relationship in pancreatic cancer patients is an observation that warrants further studies as depression could be a valuable early warning sign of pancreatic cancer.

Outcome of carcinoid heart syndrome in patients enrolled in the SwissNet cohort

BACKGROUND

Carcinoid heart disease is a rare disease which develops in patients with functional neuroendocrine tumors in an advanced tumor state. Patients diagnosed with carcinoid heart disease have a poor longtime prognosis with respect to morbidity and mortality and long-term data on patient outcomes are lacking.

METHODS AND RESULTS

In this retrospective study, we analyzed outcomes of 23 patients with carcinoid heart disease enrolled into the SwissNet database. We observed that early diagnosis with echocardiographic surveillance of carcinoid heart disease during the course of the neuroendocrine tumor disease was beneficial to overall survival of patients.

CONCLUSION

Through nationwide patient enrollment, the SwissNet registry is a powerful data tool to identify, follow-up and evaluate long-term patient outcomes in patients with rare neuroendocrine tumor driven pathologies including carcinoid heart syndrome with observational methods enabling better therapy optimization to improve patient`s long-term perspectives and survival. In line with the current ESMO recommendations, our data proposes that heart echocardiography should be included as part of the general physical assessment in patients with newly diagnosed NET.

The Role of Transthoracic Echocardiography for Assessment of Mortality in Patients with Carcinoid Heart Disease Undergoing Valve Replacement

Patients with carcinoid heart disease (CHD) are referred for valve replacement if they have severe symptomatic disease or evidence of right ventricular (RV) failure and an anticipated survival of at least 12 months. Data are lacking, however, on the role of transthoracic echocardiography in predicting outcomes. We carried out a retrospective, single-centre cohort study of patients with a biopsy-confirmed neuroendocrine tumour (NET) and CHD undergoing valve replacement for severe valve disease and symptoms of right heart failure. The aim was to identify factors associated with postoperative mortality, both within one year of surgery and during long-term follow-up. Of 88 patients with NET, 49 were treated surgically (mean age: 64.4 ± 7.6 years; 55% male), of whom 48 had a bioprosthetic tricuspid valve replacement for severe tricuspid regurgitation; 39 patients had a pulmonary valve replacement. Over a median potential follow-up of 96 months (interquartile range: 56-125), there were 37 deaths, with 30-day and one-year mortality of 14% (n = 7) and 39% (n = 19), respectively. A significant relationship between RV size and one-year mortality was observed, with 57% of those with severe RV dilatation dying within a year of surgery, compared to 33% in those with normal RV size (p = 0.039). This difference remained significant in the time-to-event analysis of long-term survival (p = 0.008). RV size was found to reduce significantly with surgery (p < 0.001). Those with persisting RV dilatation (p = 0.007) or worse RV function (p = 0.001) on postoperative echocardiography had significantly shorter long-term survival. In this single-centre retrospective study of patients undergoing surgery for CHD, increasingly severe RV dilatation on preoperative echocardiography predicted adverse outcomes, yielding a doubling of the one-year mortality rate relative to normal RV size. These data support the possibility that early surgery might deliver greater long-term benefits in this patient cohort.

Fatigue and quality of life in patients with neuroendocrine neoplasia

INTRODUCTION

Neuroendocrine Neoplasms (NEN) are rare tumours arising in the gastro-intestinal tract or lungs. Poor health related quality of life (HRQoL) is associated with the carcinoid syndrome (CS), but fatigue is also important. We aimed to quantify HRQoL and fatigue in out-patients with NEN.

METHODS

In a cross-sectional study, we included 231 patients with NEN (G1-G3). We used pre-validated questionnaires MFI-20, EQ-5D-5L and 85% responded. We collected clinical, biochemical, imaging, and pathology data from Electronic Patient files. Normative values for fatigue and HRQoL were derived from background populations.

RESULTS

Median age was 68 years (range 21-91) and 52% were male. Patients with NEN reported more fatigue and worse HRQoL compared to the background population (p < .05). Cured patients reported higher HRQoL than patients with current disease, and patients with high grade neoplasms (G2-G3) reported more anxiety and depression compared to patients with low grade G1 disease (p < .05). The CS resulted in a 9% relative loss in Quality Adjusted Life Years compared to patients without CS. (p < .05). More than 50% of patients with CS reported problems with usual activities, pain/discomfort, and anxiety/depression. Overall, 36% of patients with NEN were fatigued and 92% of these had psychological fatigue. Younger patients (<65 years) experienced more fatigue than older patients (p < .05).

CONCLUSION

Patients with NEN report significantly lower HRQoL and more fatigue compared to the background population. Especially, patients with CS had pain, discomfort, anxiety, and depression and a relative reduction in HRQoL. However, compared to other cancer types, patients with NEN experience less fatigue.

Carcinoid tumors outside the abdomen

Neuroendocrine tumors (NETs) are epithelial malignancies that can arise from multiple tissues. Gastrointestinal (GI) NETs are the most common; in this review of extra-abdominal carcinoid tumors, we focus our discussion on bronchial and thymic carcinoid tumors. Bronchial carcinoid tumors comprise a quarter of all NETs and less than 2% of all lung cancers. Thymic carcinoid tumors are extremely rare, accounting for 5% of thymic tumors. Both bronchial and thymic carcinoid tumors are histologically classified as either typical or atypical based on their mitotic rate (less than 2 or 2-10 mitoses per 10 high-powered fields (HPF), respectively). Both bronchial and thymic carcinoids can present with symptoms of obstruction and potentially carcinoid syndrome. The gold standard of management of bronchial and thymic carcinoid tumors is surgical resection. For patients with advanced disease, first-line systemic therapy is generally somatostatin analog monotherapy with octreotide or lanreotide. In patients with refractory disease, therapy generally involves peptide receptor radioligand therapy, everolimus, or cytotoxic chemotherapy. There are ongoing, prospective trials comparing the mainstays of systemic therapy for these patients, as well as ongoing evaluations of immune checkpoint inhibitors and multi-kinase inhibitors. Prognosis for both bronchial and thymic carcinoid tumors depends on histologic grade, local versus invasive disease, and extent of metastases. Herein we provide a summary of the pathophysiologic and clinical background, the current state of the field in diagnosis and management, and note of key ongoing prospective trials for patients with bronchial and thymic carcinoid tumors.

A multidisciplinary approach to the work up and management of pulmonary carcinoid tumors and DIPNECH: a narrative review

Background and Objective

Low and intermediate grade neuroendocrine tumors of the lung are uncommon malignancies representing 2% of all lung cancers. These are termed typical and atypical pulmonary carcinoid tumors. These can arise in the setting of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). The presentation, workup, management and outcomes of patients with these tumors can overlap with more common lung cancers but differ in that many of these patients have a prolonged clinical course. The objective of this narrative review is to summarize the literature and provide evidence and expert-based algorithms for work up and treatment of pulmonary carcinoids and DIPNECH.

Methods

A search of PubMed and Web of Science databases ending April 15, 2022, with the following keywords "lung carcinoid", "DIPNECH", "lung neuroendocrine," and "bronchopulmonary carcinoid".

Key Content and Findings

Pulmonary carcinoid tumors benefit from a multidisciplinary approach. Pre-treatment imaging with contrast-enhanced computed tomography, and DOTATATE positron emission tomography is required. Surgical resection is the gold standard for curative intent, and possibly including sublobar resections. Patients can recur or develop new primaries thus emphasizing the importance of surveillance; national guidelines recommend at least a 10-year follow up. A growing body of literature support the use of endobronchial therapy, with long responses documented. Systemic therapy consists of everolimus, somatostatin analogs, peptide receptor radionuclide therapy, and chemotherapy. Diffuse idiopathic pulmonary neuroendocrine tumor cell hyperplasia is rare, but series suggest somatostatin analogs may confer clinical benefit.

Conclusions

Pulmonary carcinoid tumors and DIPNECH are rare. Despite lack of regulatory approvals for advanced disease, multiple options are available but should be sequenced according to the clinical status and disease biology. Each patient should be discussed in a multidisciplinary setting and clinical trials should be considered if available.

Real-World Clinical and Patient-Reported Outcomes from the Longitudinal Telotristat Ethyl Treatment Registry of Patients with Neuroendocrine Tumors

Background

Telotristat ethyl (TE) is an oral tryptophan hydroxylase inhibitor approved for the treatment of carcinoid syndrome diarrhea (CSD) in combination with somatostatin analogs (SSAs).

Methods

This prospective, observational, single-arm study evaluated long-term patient-reported outcomes for adults initiating TE in US clinical practice from 2017 through January 2022. The primary objective was satisfaction with overall CS symptom control 6 months after initiating TE. Secondary objectives evaluated satisfaction with control of CSD, flushing, and CS symptoms, as well as work productivity/activity impairment, SSA use, and weight. All analyses were descriptive in nature.

Results

A total of 223 patients completed the baseline survey; 56% also completed the 6-month follow-up survey. Mean age was 61 years and 61% were women. After 6 months of TE treatment, the majority of patients (76%, n=95/125) reported being satisfied with control of their CS symptoms which was markedly improved from baseline (41%, n=91). Similarly, the majority of patients (78%, n=97/125) were satisfied with control of their CSD after 6 months of TE, markedly improved from baseline (36%).

Conclusion

This longitudinal observational study showed improvements in real-world clinical and humanistic outcomes for patients with CS and at least 6 months of TE treatment.

Large-cell Neuroendocrine Carcinoma of the Lung with Carcinoid Syndrome: A Case Report

A 76-year-old woman was admitted to our hospital for refractory diarrhea with a poor antidiarrheal effect. Chest and abdominal computed tomography revealed a 24×22-mm mass in the left upper lobe of lung and multiple masses in the liver. Urine 5-Hydroxy indol acetic acid was markedly elevated. A liver biopsy revealed large-cell neuroendocrine carcinoma with serotonin production, suggestive of a lung origin, and a lung biopsy revealed combined large-cell neuroendocrine carcinoma and squamous cell carcinoma. Therefore, we made a definitive diagnosis of carcinoid syndrome caused by large-cell neuroendocrine carcinoma of the lung. Although chemotherapy was performed after diagnosis, the patient died 50 days postadmission.

Radioembolization of Secondary Hepatic Malignancies

Cancer has become the leading cause of mortality in America, and the majority of patients eventually develop hepatic metastasis. As liver metastases are frequently unresectable, the value of liver-directed therapies, such as transarterial radioembolization (TARE), has become increasingly recognized as an integral component of patient management. Outcomes after radioembolization of hepatic malignancies vary not only by location of primary malignancy but also by tumor histopathology. This article reviews the outcomes of TARE for the treatment of metastatic colorectal cancer, metastatic breast cancer, and metastatic neuroendocrine tumors, as well as special considerations when treating metastatic disease with TARE.

Tumor neuroendocrino en recto simulando una neoplasia benigna: reporte de caso y revisión de la literatura

Los tumores neuroendocrinos se definen como un grupo heterogéneo de neoplasias de origen epitelial, provenientes de células enterocromafines diseminadas por todo el organismo, y representan alrededor del 1 al 4 % de todas las neoplasias. Su mayor distribución se encuentra en el tracto gastrointestinal, donde se localiza el 75 % de los tumores neuroendocrinos, siendo los ubicados en el recto, el 27 % de todos los que afectan el tracto gastrointestinal. A propósito de esta revisión de tema, presentamos el caso de un paciente de 71 años de edad, que consultó por sangrado rectal rojo rutilante, sin otra sintomatología asociada, y se le diagnosticó un tumor neuroendocrino grado 1, que se comportaba como una lesión benigna del recto.

Use of healthcare REsources and associated COsts in controlled versus uncontrolled carcinoid SYndrome in patients with neuroendocrine tumours: the RECOSY study

PURPOSE

To report healthcare resource use and associated costs in controlled versus uncontrolled carcinoid syndrome (CS) in patients with neuroendocrine tumours.

METHODS

A cross-sectional, non-interventional multicentre study was conducted with retrospective data analysis. Resource use was compared between two patient groups: those with controlled CS (> 12 months with no uncontrolled CS episodes) and uncontrolled CS (< 12 months since last uncontrolled episode). Patients were matched for age, sex, and origin and grade of tumour. When no matching patients were available, data from deceased patients were used. Information on healthcare resource use came from review of medical records, patient history and physician reports. Working capacity was assessed using the Work Productivity and Activity Impairment General Health questionnaire.

RESULTS

Twenty-six university hospitals in Spain participated, between July 2017 and April 2018. 137 patients were enrolled; 104 were analysed (2 groups of 52). Patients with uncontrolled CS had 10 times more emergency department (ED) visits (mean 1.0 vs 0.10 visits; P = 0.0167), were more likely to have a hospital admission (40.4% vs 19.2%; P = 0.0116) and had longer hospital stays (mean 7.87 vs 2.10 days; P = 0.0178) than those with controlled CS. This corresponded to higher annual hospitalisation costs (mean €5511.59 vs €1457.22; P = 0.028) and ED costs (€161.25 vs €14.85; P = 0.0236). The mean annual total healthcare costs were 60.0% higher in patients with uncontrolled than controlled CS (P = NS).

CONCLUSION

This study quantifies higher health resource use, and higher hospitalisation and ED costs in patients with uncontrolled CS. Better control of CS may result 3in lower medical costs.

Opportunities to Improve Symptom Control with Somatostatin Congeners in GEP-NETs: A Review of Key Issues

Octreotide acetate (octreotide) is the most prescribed and most studied somatostatin congener, or analog, for gastroenteropancreatic neuroendocrine tumors (GEP‐NETs) and carcinoid syndrome, the latter of which may be characterized by debilitating diarrhea and flushing. Approved in the U.S. more than 30 years ago, octreotide is widely used to control the symptoms of carcinoid syndrome and has been shown to demonstrate antiproliferative activity. The two formulations available in the U.S. include a subcutaneous immediate‐release (IR) injection introduced in 1989 and a long‐acting repeatable (LAR) intramuscular injection approved in 1999. Lanreotide depot (lanreotide), a more recent somatostatin congener, has been available in the U.S. since 2014.

Despite widespread use of octreotide LAR, several key challenges exist with the current depot‐based treatment paradigm. Studies indicate that LAR formulations are associated with continued unmet patient needs, owing in part to a loss of bioactivity over time that may necessitate progressive supplemental treatment with IR octreotide to adequately control symptoms. Clinicians should understand the key differences in the pharmacokinetic profiles of the LAR and IR formulations that may contribute to bioactivity loss and somatostatin receptor desensitization. In addition, there is a need to re‐evaluate the role of IR octreotide in combination with depot therapy to provide consistent bioavailability and better control of carcinoid syndrome symptoms.

The purpose of this review is to explore all these issues and to re‐establish a rationale for the IR formulation, particularly with respect to novel use cases and its use during the COVID‐19 pandemic.

This review explores key challenges with depot‐based treatment of gastroenteropancreatic neuroendocrine tumors with octreotide and the key differences between the LAR and IR formulations.

Can an amino acid mixture alleviate gastrointestinal symptoms in neuroendocrine tumor patients?

Background

Neuroendocrine tumors, although relatively rare in incidence, are now the second most prevalent gastrointestinal neoplasm owing to indolent disease biology. A small but significant sub-group of neuroendocrine tumor patients suffer from diarrhea. This is usually secondary to carcinoid syndrome but can also be a result of short gut syndrome, bile acid excess or iatrogenic etiologies. Recently, an amino acid based oral rehydration solution (enterade Advanced Oncology Formula) was found to have anti-diarrheal properties in preclinical models.

Methods

A retrospective chart review of all NET patients treated with enterade AO was performed after IRB approval.

Results

Ninety-eight NET patients who had received enterade AO at our clinic from May 2017 through June 2019 were included. Patients (N=49 of 98) with follow up data on bowel movements (BMs) were included for final analysis. Eighty-four percent of patients (41/49) had fewer BMs after taking enterade AO and 66% (27/41) reported more than 50% reduction in BM frequency. The mean number of daily BMs was 6.6 (range, 320) at baseline before initiation of therapy, while the mean number of BMs at 1 week time point post enterade AO was 2.9 (range, 011).

Conclusions

Our retrospective observations are encouraging and support prospective validation with appropriate controls in NET patients. This is first published report of the potential anti-diarrheal activity of enterade AO in NET patients.

A forgotten diagnosis in right heart failure: A case report and literature review

Carcinoid heart disease is a well-known complication of carcinoid syndrome that affects morbidity and mortality. Carcinoid heart disease may be asymptomatic in the early stages; therefore, patients with carcinoid syndrome should be screened to prevent misdiagnosis.

CHALLENGES OF AN OVARIAN NEUROENDOCRINE METASTASIS OF ADVANCED SMALL-CELL LUNG CARCINOMA - LITERATURE REVIEW AND CASE REPORT

Metastatic tumors account for 5-10% of all ovarian malignancies. They are usually bilateral tumors with a multinodular surface and extensive extra ovarian spread. Lung cancer is a rare source (0.3% of metastatic ovarian tumors). Among synchronous primary cancers, ovarian cancer is most frequently associated with endometrial cancer. The differential diagnosis between a primary ovarian carcinoma, synchronous primary cancers, and metastatic ovarian carcinoma is very important, as the treatment and prognosis are markedly different. We report the case of a 25-year-old woman who had been diagnosed and treated for stage IIIB small cell lung carcinoma (SCLC). Imaging undertaken for abdominal pain revealed a unilateral 8.5 cm ovarian tumor for which adnexectomy was performed. Histology and immunohistochemistry led to the diagnosis of ovarian metastasis from SCLC, a high-grade neuroendocrine lung tumor. This patient's particular features, all infrequent in a metastatic tumor, are the lesion's unilaterality (atypical for ovarian metastases in other cancers, but often observed in SCLC), the smooth ovarian surface with intact capsule, and the absence of intra-abdominal dissemination. The patient developed liver and vertebral metastases. This report focuses on the differential diagnosis between primary and metastatic ovarian neoplasms. We performed an extensive search of the literature on SCLC and ovarian metastases. Immunohistochemistry is essential for diagnosis when imaging and the pathological evaluation of the ovarian tumor cannot make the differential diagnosis.

Gastroenteropancreatic neuroendocrine neoplasms: A clinical snapshot

Our understanding about the epidemiological aspects, pathogenesis, molecular diagnosis, and targeted therapies of neuroendocrine neoplasms (NENs) have drastically advanced in the past decade. Gastroenteropancreatic (GEP) NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors. Most NENs are well-differentiated, and slow growing. Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin, glucagon, vasoactive intestinal polypeptide, gastrin, somatostatin, adrenocorticotropin, growth hormone releasing hormone, parathyroid hormone-related peptide, serotonin, histamine, and 5-hydroxy indole acetic acid (5-HIAA). Biomarkers such as pancreatic polypeptide, human chorionic gonadotrophin subunits, neurotensin, ghrelin, and calcitonin are used in the diagnosis of non-functional NENs. 5-HIAA levels correlate with tumour burden, prognosis and development of carcinoid heart disease and mesenteric fibrosis, however several diseases, medications and edible products can falsely elevate the 5-HIAA levels. Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs. Emerging novel biomarkers include circulating tumour cells, circulating tumour DNA, circulating micro-RNAs, and neuroendocrine neoplasms test (NETest) (simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood). NETest has high sensitivity (85%-98%) and specificity (93%-97%) for the detection of gastrointestinal NENs, and is useful for monitoring treatment response, recurrence, and prognosis. In terms of management, surgery, radiofrequency ablation, symptom control with medications, chemotherapy and molecular targeted therapies are all considered as options. Surgery is the mainstay of treatment, but depends on factors including age of the individual, location, stage, grade, functional status, and the heredity of the tumour (sporadic vs inherited). Medical management is helpful to alleviate the symptoms, manage inoperable lesions, suppress postoperative tumour growth, and manage recurrences. Several molecular-targeted therapies are considered second line to somatostatin analogues. This review is a clinical update on the pathophysiological aspects, diagnostic algorithm, and management of GEP NENs.

Gastroenteropancreatic neuroendocrine neoplasms: A clinical snapshot

Our understanding about the epidemiological aspects, pathogenesis, molecular diagnosis, and targeted therapies of neuroendocrine neoplasms (NENs) have drastically advanced in the past decade. Gastroenteropancreatic (GEP) NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors. Most NENs are well-differentiated, and slow growing. Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin, glucagon, vasoactive intestinal polypeptide, gastrin, somatostatin, adrenocorticotropin, growth hormone releasing hormone, parathyroid hormone-related peptide, serotonin, histamine, and 5-hydroxy indole acetic acid (5-HIAA). Biomarkers such as pancreatic polypeptide, human chorionic gonadotrophin subunits, neurotensin, ghrelin, and calcitonin are used in the diagnosis of non-functional NENs. 5-HIAA levels correlate with tumour burden, prognosis and development of carcinoid heart disease and mesenteric fibrosis, however several diseases, medications and edible products can falsely elevate the 5-HIAA levels. Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs. Emerging novel biomarkers include circulating tumour cells, circulating tumour DNA, circulating micro-RNAs, and neuroendocrine neoplasms test (NETest) (simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood). NETest has high sensitivity (85%-98%) and specificity (93%-97%) for the detection of gastrointestinal NENs, and is useful for monitoring treatment response, recurrence, and prognosis. In terms of management, surgery, radiofrequency ablation, symptom control with medications, chemotherapy and molecular targeted therapies are all considered as options. Surgery is the mainstay of treatment, but depends on factors including age of the individual, location, stage, grade, functional status, and the heredity of the tumour (sporadic vs inherited). Medical management is helpful to alleviate the symptoms, manage inoperable lesions, suppress postoperative tumour growth, and manage recurrences. Several molecular-targeted therapies are considered second line to somatostatin analogues. This review is a clinical update on the pathophysiological aspects, diagnostic algorithm, and management of GEP NENs.

VIPoma: a rare cause of diarrhea. A case report

Introduction: Vasoactive intestinal peptide-secreting tumor (VIPoma) is a rare functional pancreatic neuroendocrine tumor (F-PNET) characterized by secretory diarrhea, hypokalemia, and hypochlorhydria. Its low incidence and high risk of malignancy pose a clinical challenge that requires a high degree of clinical suspicion. Case presentation: A 61-year-old woman visited the emergency department of a tertiary care hospital in Medellín, Colombia, due to chronic diarrhea (7 months) that led to dehydration, renal failure, metabolic acidosis, and hypokalemia. As a result, a treatment based on loperamide, intravenous fluids and broad-spectrum antibiotics was started. In addition, chromogranin A levels of 477 ug/L (<100) were reported, while an abdominal MRI showed a 33x30mm mass in the head and uncinate process of the pancreas, so outpatient surgical management was decided. However, three days after discharge, and due to the persistence of clinical signs, the patient was admitted to another hospital (also a tertiary care hospital), where, given the high suspicion of VIPoma, and once the diarrhea was solved, the mass was removed (Whipple procedure) without any complication. Finally, the diagnosis was confirmed based on serum vasoactive intestinal peptide levels (930 pg/mL (RV<75)) and the pathology report (PNET tumor grade 2). Two years after the surgery, the patient was asymptomatic, and no residual lesions or metastases were evident in a control MRI. Conclusion: Late diagnosis of VIPoma is associated with worsened quality of life, severe complications, and high prevalence of metastasis. Therefore, it should be suspected in patients with chronic secretory diarrhea that is not caused by an infection, since early diagnosis and timely treatment can contribute to achieving better survival rates in these patients.

Systemic mastocytosis with flushing and hypotension: A case report and literature review

Systemic mastocytosis (SM) is a heterogeneous disease of the bone marrow, which is characterized by the abnormal proliferation and infiltration of mast cells in one or more organs, such as the skin, bone marrow, digestive tract, liver and spleen. Urticaria pigmentosa is a typical but infrequent manifestation of SM. Other clinical presentations are non-specific, varying from pruritus and hypotension to multiple organ dysfunction, which may be lethal when hemodynamic changes occur, such as the sharp decline in blood pressure observed in the present case. In patients who lack skin lesions, the diagnosis of SM is frequently challenging. The present study reported on a 58-year-old male who presented with episodic flushing and syncope. The patient demonstrated marked neutrophilia and reduced blood potassium concentrations soon after the onset of each episode, which was able to last several hours, ranging from once to four times a year. SM without skin lesions was suspected and confirmed after multifocal bone marrow aspiration, which revealed dense infiltrates of mast cells (≥15 mast cells), with positive toluidine blue and CD117 staining. The present case illustrates the significance of taking SM or mast cell activation syndrome into consideration when unexplained recurrent hypotension or even syncope are observed, care should be taken to exclude differential diagnoses, as some of them may have much poorer prognoses and require alternative treatments.

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.

Health resource utilisation by patients with neuroendocrine tumours with or without carcinoid heart disease: a multinational study

Background

Carcinoid heart disease (CHD) is a rare and severe complication from carcinoid syndrome which may be associated with high health resource utilisation (HRU). We aimed to compare HRU between patients with and without CHD.

Methods

Multicentre retrospective study of 137 consecutive patients with neuroendocrine tumours (NET) and elevated urinary 5-hydroxyindoleacetic acid treated in seven large hospitals in Latin America. We used the chi-squared test for binary variables and the Mann–Whitney test for quantitative correlations. Variables were entered into a multivariable linear regression model for higher HRU.

Results

One-third of the patients had (45) had CHD. Patients with CHD had significantly more emergency visits and echocardiograms as compared to patients without CHD. In the bivariate models, CHD (R² = 0.61, p = 0.01), private health system (R² = 0.63, p = 0.02) and simultaneous cardiovascular comorbidities (R² = 0.61, p = 0.04) were associated with a higher HRU. The multivariate model pointed out the accumulated effect of variables on HRU (R² = 0.2, p < 0.01).

Conclusions

NET patients with CHD present higher HRU independently of other clinical factors or health system. Effectively treating carcinoid syndrome, and likely delaying the onset of CHD, may potentially reduce the amount of HRU by these patients.

Serotonin pathway in carcinoid syndrome: Clinical, diagnostic, prognostic and therapeutic implications

Carcinoid syndrome represents the most common functional syndrome that affects patients with neuroendocrine neoplasms. Its clinical presentation is really heterogeneous, ranging from mild and often misdiagnosed symptoms to severe manifestations, that significantly worsen the patient's quality of life, such as difficult-to-control diarrhoea and fibrotic complications. Serotonin pathway alteration plays a central role in the pathophysiology of carcinoid syndrome, accounting for most clinical manifestations and providing diagnostic tools. Serotonin pathway is complex, resulting in production of biologically active molecules such as serotonin and melatonin, as well as of different intermediate molecules and final metabolites. These activities require site- and tissue-specific catalytic enzymes. Variable expression and activities of these enzymes result in different clinical pictures, according to primary site of origin of the tumour. At the same time, the biochemical diagnosis of carcinoid syndrome could be difficult even in case of typical symptoms. Therefore, the accuracy of the diagnostic methods of assessment should be improved, also attenuating the impact of confounding factors and maybe considering new serotonin precursors or metabolites as diagnostic markers. Finally, the prognostic role of serotonin markers has been only evaluated for its metabolite 5-hydroxyindole acetic acid but, due to heterogeneous and biased study designs, no definitive conclusions have been achieved. The most recent progress is represented by the new therapeutic agent telotristat, an inhibitor of the enzyme tryptophan hydroxylase, which blocks the conversion of tryptophan in 5-hydroxy-tryptophan. The present review investigates the clinical significance of serotonin pathway in carcinoid syndrome, considering its role in the pathogenesis, diagnosis, prognosis and therapy.

Constrictive bronchiolitis in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

Background

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterised by multifocal proliferation of neuroendocrine cells and belongs in the spectrum of pulmonary neuroendocrine tumours. Some patients with DIPNECH develop airflow obstruction but the relationship between the two entities remains unclear.

Methods

We performed a computer-assisted search of the Mayo Clinic's electronic medical records for biopsy-proven cases of DIPNECH. We extracted clinical, pulmonary function, imaging and histopathological data along with treatments and outcomes.

Results

Among 44 patients with DIPNECH 91% were female and the median age was 65 years (interquartile range 56–69 years); 73% were never-smokers. Overall, 38 patients (86%) had respiratory symptoms including cough (68%) and dyspnoea (30%); 45% were previously diagnosed to have asthma or COPD. Pulmonary function testing showed an obstructive pattern in 52%, restrictive pattern in 11%, mixed pattern in 9%, nonspecific pattern in 23%, and was normal in 5%. On chest computed tomography scan, 95% manifested diffuse nodules and 77% manifested mosaic attenuation. For management, 25% of patients were observed without pharmacological therapy, 55% received an inhaled bronchodilator, 41% received an inhaled corticosteroid, 32% received octreotide; systemic steroids, azithromycin, or combination chemotherapy was employed in four patients (9%). Of 24 patients with available follow-up pulmonary function tests, 50% remained stable, 33% worsened and 17% improved over a median interval of 21.3 months (interquartile range 9.7–46.9 months).

Conclusion

DIPNECH occurs mostly in women and manifests diffuse pulmonary nodules and mosaic attenuation on imaging. It is commonly associated with airflow obstruction due to constrictive bronchiolitis, which manifests limited response to current pharmacological therapy.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is an under-recognised cause of obstructive lung disease in women. Constrictive bronchiolitis associated with DIPNECH manifests limited response to currently employed therapies.https://bit.ly/3c3RZoe

Role of Diet in the Management of Carcinoid Syndrome: Clinical Recommendations for Nutrition in Patients with Neuroendocrine Tumors

Nutrition and metabolism are altered in patients with gastroenteropancreatic neuroendocrine tumors, which is related to excessive production of gastrointestinal hormones, peptides, and amines that can cause maldigestion, diarrhea, steatorrhea, and altered gastrointestinal motility. Patients with carcinoid syndrome are at risk of malnutrition due to tryptophan depletion, reduced intake of food, and loss of appetite because of diarrhea and/or flushing. To date, there is limited information on the nutritional issues faced by patients with neuroendocrine tumors, and on what specific recommendations should be made to patients concerning nutrition at various stages of the disease process. Dietary planning should therefore be an integral part of multidisciplinary management for patients with neuroendocrine tumors. Herein, we review current guidance for nutrition in patients with neuroendocrine tumors, focusing on intake of amines and foods to avoid, as well as concurrent medications. We also propose a new and practical food pyramid based on the principles of Mediterranean diet 4.0 that can be easily adapted according to the unmet needs of patients with neuroendocrine tumors at all stages of disease. The overarching goal of the present review is to create greater awareness of nutritional care and considerations that should be given to patients with neuroendocrine tumors.

Pheochromocytoma Metastasing to the Jaw: Review of the Literature and New Case

Pleochromocytoma is a benign neuroectodermal tumor of the adrenal medulla. Ten to thirty percent of these tumors become metastatic. The bone is the most frequent site for metastasis but jaw involvement is reported rarely. A case of mandibular involvement is reported and a literature review in this topic is presented. Preoperative management of these patients undergoing general anesthesia is not a routine practice in maxillofacial surgery, so this topic is also is explained.

Incidental Diagnosis of Carcinoid Disease by Intraoperative Transesophageal Echocardiography and Subsequent Discovery of a Neuroendocrine Tumor during Cardiac Surgery

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Carcinoid heart disease typically involves the right-sided valves of the heart.

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Carcinoid valves are fixed and retracted with limited mobility.

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Pathognomonic appearance of valves increases carcinoid likelihood.

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Carcinoid diagnosis has intraoperative implications.

A Budget Impact Model of the Addition of Telotristat Ethyl Treatment to the Standard of Care in Patients with Uncontrolled Carcinoid Syndrome

BACKGROUND

Carcinoid syndrome, a rare condition in patients with neuroendocrine tumours, characterised by flushing and diarrhoea, severely affects patients' quality of life. The current carcinoid syndrome standard of care includes somatostatin analogues, but some patients experience uncontrolled symptoms despite somatostatin analogue therapy. Telotristat ethyl is a novel treatment approved by the European Medicines Agency (EMA) and US FDA that significantly reduces bowel movement frequency in patients with uncontrolled carcinoid syndrome.

OBJECTIVE

We developed a model to evaluate the 5-year budget impact of introducing telotristat ethyl to standard care in Swedish patients with uncontrolled carcinoid syndrome.

METHODS

Treatment response in the 12-week phase III TELESTAR trial (NCT01677910) informed telotristat ethyl efficacy; subsequently, health states were captured by a Markov model using 4-week cycles. TELESTAR open-label extension data informed telotristat ethyl discontinuation. The number of treatment-eligible patients was estimated from literature reviews reporting the prevalence, incidence and mortality of carcinoid syndrome. A Swedish database study informed real-world costs related to carcinoid syndrome and carcinoid heart disease costs. Telotristat ethyl market share was assumed to increase annually from 24% (year 1) to 70% (year 5).

RESULTS

Over the 5-year model horizon, 44 patients were expected to initiate telotristat ethyl treatment. The cumulative net budget impact of adding telotristat ethyl to current standard of care was €172,346; per-year costs decreased from €66,495 (year 1) to €29,818 (year 5). Increased drug costs from adding telotristat ethyl were offset by reduced costs elsewhere.

CONCLUSIONS

The expected budget impact of adding telotristat ethyl to the standard of care in Sweden was relatively low, largely because of the rarity of carcinoid syndrome.

Carcinoid Syndrome: A Review

Carcinoid syndrome (CS) is a paraneoplastic syndrome caused by the release of serotonin and other substances from well-differentiated neuroendocrine tumors (NETs). The hallmark symptoms of carcinoid syndrome are flushing and diarrhea; atypical signs and symptoms can include wheezing, abdominal pain, valvular heart disease, telangiectasias, pellagra, and the complications of mesenteric fibrosis, including ureteral obstruction, bowel obstruction, and bowel ischemia. These symptoms are mediated by the release of serotonin (5-HT), histamine, kallikrein, prostaglandins, and tachykinins. The diagnosis of CS requires these symptoms and corresponding elevations in lab tests. Treatment options include surgery and medical management with somatostatin analogs.

An unusual case of proton pump inhibitor induced hyperchromograninemia

Objective: To describe an unusual case of symptomatic hyperchromograninemia associated with proton pump inhibitor (PPI) use.

Case Summary: A 55-year-old man with stage 1 follicular lymphoma and GERD on omeprazole presented with symptoms suggesting carcinoid syndrome. The only positive finding on workup was a markedly elevated level of chromogranin A and no carcinoid tumor was identified. Omeprazole was discontinued, following which his symptoms resolved and chromogranin A levels returned to normal. To the best of our knowledge, no symptoms have been previously reported in association with PPI-induced hyperchromograninemia.

Discussion: The reliability of chromogranin A as a marker for neuroendocrine tumors is of growing concern. The reasons for the associated symptomatology in this case are unclear but could involve physiologic effects of chromogranin A breakdown products. The role of pharmacogenomics in PPI metabolism is discussed as a potential explanation for the significant hyperchromograninemia.

Conclusion: The phenomenon of PPI-induced hyperchromograninemia is highlighted for providers especially in the context of neuroendocrine tumor diagnosis and surveillance. The need for more research into chromogranins is proposed.

Update on Pathophysiology, Treatment, and Complications of Carcinoid Syndrome

Carcinoid syndrome (CS) develops in patients with hormone-producing neuroendocrine neoplasms (NENs) when hormones reach a significant level in the systemic circulation. The classical symptoms of carcinoid syndrome are flushing, diarrhoea, abdominal pain, and wheezing. Neuroendocrine neoplasms can produce multiple hormones: 5-hydroxytryptamine (serotonin) is the most well-known one, but histamine, catecholamines, and brady/tachykinins are also released. Serotonin overproduction can lead to symptoms and also stimulates fibrosis formation which can result in development of carcinoid syndrome-associated complications such as carcinoid heart disease (CaHD) and mesenteric fibrosis. Transforming growth factor beta (TGF-β) is one of the main factors in developing fibrosis, but platelet-derived growth factor (PDGF), basic fibroblast growth factor (FGF2), and connective tissue growth factor (CTGF or CCN2) are also related to fibrosis development. Treatment of CS focuses on reducing serotonin levels with somatostatin analogues (SSA's). Telotristat ethyl and peptide receptor radionuclide therapy (PRRT) have recently become available for patients with symptoms despite being established on SSA's. Screening for CaHD is advised, and early intervention prolongs survival. Mesenteric fibrosis is often present and associated with poorer survival, but the role for prophylactic surgery of this is unclear. Depression, anxiety, and cognitive impairment are frequently present symptoms in patients with CS but not always part of their care plan. The role of antidepressants, mainly SSRIs, is debatable, but recent retrospective studies show evidence for safe use in patients with CS. Carcinoid crisis is a life-threatening complication of CS which can appear spontaneously but mostly described during surgery, anaesthesia, chemotherapy, PRRT, and radiological procedures and may be prevented by octreotide administration.