Management of neuroendocrine tumors in children, adolescents, and young adults

Characteristics and Management of Children with Appendiceal Neuroendocrine Neoplasms: A Single-Center Study

BACKGROUND/OBJECTIVES

Appendiceal neuroendocrine neoplasms (ANENs) are usually found incidentally during histology examination after appendectomy for appendicitis. Due to their rarity in pediatric populations, there is no consensus on treatment or follow-up. The analysis of patients with ANENs of our and other studies will increase the understanding of this tumor.

METHODS

Pediatric patients with ANENs were uniformly managed at our center between 1998 and 2023. Patients' presenting symptoms, surgery, tumor histology, post-surgical work-up, follow-up and outcome were analyzed.

RESULTS

Our report describes 17 patients with a diagnosis of ANEN after appendectomy. The median age was 14 years (range of 4-17 years). Tumors were located at the tip of the appendix in 58.8% of cases and only one had a diameter >1 cm. All were well-differentiated tumors with free resection margins. The submucosa was invaded in five cases, muscularis propria in eight and subserosa in four. Post-appendectomy work-up included tumor marker measurement, abdominal ultrasound and computed tomography or magnetic resonance imaging, chest X-ray and octreotide scintigraphy. No residual tumors or metastases were detected. Additional surgery was not necessary. Follow-up was carried out for a median duration of 6 years (range of 1-10 years). Only one patient was lost to follow-up and all other patients are alive without tumor recurrence.

CONCLUSIONS

The tumor characteristics of our patients confirmed data from the literature. With the lack of a sufficient number of large prospective trials, it is important to add more information to confirm the benign nature and excellent outcome of this tumor, even without additional surgery. Consensus guidelines are needed for ANENs in pediatric populations.

Preclinical evidence for employing MEK inhibition in NRAS mutated pediatric gastroenteropancreatic neuroendocrine-like tumors

BACKGROUND

Pediatric gastroenteropancreatic neuroendocrine tumors are exceedingly rare, resulting in most pediatric treatment recommendations being based on data derived from adults. Trametinib is a kinase inhibitor that targets MEK1/2 and has been employed in the treatment of cancers harboring mutations in the Ras pathway.

METHODS

We utilized an established human pediatric gastroenteropancreatic neuroendocrine-like tumor patient-derived xenograft (PDX) with a known NRAS mutation to study the effects of MEK inhibition. We evaluated the effects of trametinib on proliferation, motility, and tumor growth in vivo. We created an intraperitoneal metastatic model of this PDX, characterized both the phenotype and the genotype of the metastatic PDX and again, investigated the effects of MEK inhibition.

RESULTS

We found target engagement with decreased ERK1/2 phosphorylation with trametinib treatment. Trametinib led to decreased in vitro cell growth and motility, and decreased tumor growth and increased animal survival in a murine flank tumor model. Finally, we demonstrated that trametinib was able to significantly decrease gastroenteropancreatic neuroendocrine intraperitoneal tumor metastasis.

CONCLUSIONS

The results of these studies support the further investigation of MEK inhibition in pediatric NRAS mutated solid tumors.

Childhood neuroendocrine tumors of the digestive system: A single center experience

The prevalence and incidence of neuroendocrine tumors (NETs) are increasing in the pediatric population. This increase can be associated with improved diagnostics and increased detection rates of the disease. We aimed to discuss the clinical and pathological characteristics of patients with this rare disease who were followed and treated at our center.The medical records of children (aged 0-18 years) with NETs of the digestive system, followed up and treated between 2007 and 2020 at Ondokuz Mayis University Faculty of Medicine, were reviewed.Overall, 16 patients (8 girls and 8 boys) were analyzed. Fifteen patients had NETs in the appendix; 14 of these had grade I NETs, and 1 had grade II NETs. No additional surgery was performed except for appendectomy. All patients were in complete remission at the last follow-up (median 38 months). The other patient, a 12-year-old girl, had a primary hepatic neuroendocrine carcinoma (grade III NET). Three cycles of neoadjuvant and adjuvant platinum-based chemotherapy were administered, and right hepatectomy was performed to remove the mass. The patient is being followed-up for approximately 3 years without disease recurrence.Most NETs are observed in adults, and most studies have focused on this population. Unlike adults, increasing awareness of the disease in the pediatric population (especially in cases of acute appendicitis), discovering therapeutic treatments, and sharing experiences are crucial for developing an optimal therapeutic approach for pediatric NETs.

Malignant pancreatic tumor other than solid pseudopapillary tumor in pediatric patients: A single-center experience

Pancreatic tumors, except solid pseudopapillary tumors (SPTs), are rare in pediatric patients. Herein, we report various types of pancreatic tumors in pediatric patients and review the literature regarding their treatments and prognosis.We retrospectively reviewed the data of pediatric patients who underwent surgery for pancreatic tumors, excluding SPTs, between January 2009 and December 2019 at Seoul National University Children's Hospital. A total of 35 pediatric patients were identified as having undergone surgery for pancreatic tumors. Of these patients, 30 were excluded because the tumor was identified as an SPT.The diagnoses of the five remaining (non-SPT) pancreatic tumors were pancreatic neuroendocrine tumor, mixed acinar neuroendocrine carcinoma, kaposiform hemangioendothelioma, and intraductal papillary mucinous neoplasm. All five patients survived; however, recurrence and liver metastasis were observed in one patient. The detailed demographics, treatments, and prognosis of each patient were reviewed.Despite the rarity and low incidence of pancreatic tumors in pediatric patients, four types of non-SPT tumors are reported here. Hence, the possibility of these should not be overlooked, especially since the diagnosis and adjuvant treatment differ vastly between the tumor types.

Pancreatic VIPoma as a Differential Diagnosis in Chronic Pediatric Diarrhea: A Case Report and Review of the Literature

Chronic diarrhea is a common chief complaint in the pediatric population with a wide range of diagnostic differentials; as such, whilst suspecting common causes, less prevalent conditions tend to be overlooked, such as neuroendocrine tumor pathologies. VIPomas are characterized by hypersecretion of the vasoactive intestinal peptide (VIP), causing watery diarrhea, hypokalemia, and achlorhydria. Nonetheless, its low incidence rate in children makes it an easily unnoticed pathology. Herein, we report a case of a 14-year-old female patient and a review of relevant literature. The patient complained of 7-month history of watery diarrhea, multiple emetic episodes, and relevant past medical history of multiple hospitalizations. Chronic diarrheal disease work-up studies, including a high VIP scintigram, showed a lesion suggestive of a VIPoma-type neuroendocrine pancreatic tumor. A distal pancreatectomy was performed with a complete resolution of the symptoms. When faced with a pediatric patient presenting with chronic secretory diarrhea and whose work-up studies rule out the most common pathologies, the possible presence of a neuroendocrine tumor as VIPoma should be considered.

Extra-appendicular neuroendocrine tumors: A report from the TREP project (2000-2020)

BACKGROUND

Extra-appendicular neuroendocrine tumors (NETs) are very rare tumors. While diagnostic and therapeutic guidelines are well established for adults, data on children and adolescents are lacking.

PATIENTS AND METHODS

Patients with a diagnosis of extra-appendicular NET registered on the Tumori Rari in Età Pediatrica - Rare Tumors in Pediatric Age (TREP) from 2000 to 2020 were analyzed. Clinical characteristics including patients' presentation, tumor features, treatment, and outcome were reviewed.

RESULTS

Twenty-seven patients with extra-appendicular NET registered on TREP with a median age of 173 months. The primary site was the pancreas (12) or bronchi (10) in the majority of cases. Other primary sites included the thymus, Meckel's diverticulum, and liver. Thirteen (48%) of tumors extended beyond the organ of origin: four invaded neighboring organs and/or regional nodes and nine involved distant metastases. The 3-year event-free survival (EFS) for those with localized disease was superior to those with metastatic disease (66.6% 95% CI 5-95% vs 33% 95% CI 5-68%, respectively; P = .005). A complete resection was feasible in 17 patients. The 3-year EFS in these patients was superior to those with no or incomplete resection (R0 vs R1/R2, respectively; P = .007). Overall, 16 children had no evidence of disease at follow-up, and one is alive with disease; five died, and five were lost to follow-up.

CONCLUSIONS

Data from our experience demonstrated a wide heterogeneity of presentation and outcome of these tumors. Localized disease and complete surgical resection were the main prognostic factors of good outcome. Other therapies may have a role in prolonging survival in metastatic disease.

Theragnostic Aspects and Radioimmunotherapy in Pediatric Tumors

The use of theragnostic radiopharmaceuticals in nuclear medicine has grown rapidly over the years to combine the diagnosis and therapy of tumors. In this review, we performed web-based and desktop literature research to investigate and explain the potential role of theragnostic imaging in pediatric oncology. We focused primarily on patients with aggressive malignancies such as neuroblastoma and brain tumors, to select patients with the highest chance of benefit from personalized therapy. Moreover, the most critical and groundbreaking applications of radioimmunotherapy in children’s oncology were examined in this peculiar context. Preliminary results showed the potential feasibility of theragnostic imaging and radioimmunotherapy in pediatric oncology. They revealed advantages in the management of the disease, thereby allowing an intra-personal approach and adding new weapons to conventional therapies.

Long-Term Follow-Up of a Patient with Primary Presacral Neuroendocrine Tumor: A Case Report with Literature Review

BACKGROUND Primary neuroendocrine tumors (NETs) in the retroperitoneal space are extremely rare. We report the case of a patient diagnosed with primary presacral NET in the retroperitoneum that was initially suspected to be hepatic metastasis, who was followed up for more than 8 years. CASE REPORT A 78-year-old man was referred to our hospital for the treatment of a hepatic mass. Following resection, the patient was diagnosed with a grade 2 well-differentiated NET. A thorough evaluation to identify the primary tumor detected small well-demarcated presacral nodules on In-111 octreotide single-photon emission tomography/computed tomography (SPECT/CT). Metastases to other locations were not observed. Presacral nodules were difficult to remove using the surgical approach; therefore, we decided to follow up closely. After 4 years, the patient was diagnosed with recurrent hepatic metastasis and peritoneal seeding. Although combination therapy of everolimus and octreotide long-acting repeatable was administered, it was discontinued owing to disease progression. Baseline Ga-68 DOTATOC positron emission tomography-computed tomography revealed adequate avidity for the lesions observed on SPECT/CT; therefore, 5 cycles of peptide receptor radionuclide therapy (PRRT) were administered, after which stable disease was maintained. CONCLUSIONS We identified an extremely rare primary retroperitoneal NET on In-111 octreotide SPECT/CT. During long-term follow-up, although the patient presented with recurrent hepatic metastases and peritoneal seeding, PRRT was successful in stabilizing the disease.

Multifocal Appendiceal Carcinoid Tumor in an Adolescent: A Case Report and Review of the Literature

Appendiceal carcinoid tumors in children and adolescents are rare. This report describes a case of a multifocal appendiceal carcinoid tumor identified incidentally following appendectomy in an adolescent. In this report, we describe the staging process and surgical management for focal and locally invasive appendiceal carcinoid tumors and highlight the rarity of multifocality in this location. The diagnostic and pathologic challenges for this case are presented.

Neuroendocrine Tumors in Pediatrics

Neuroendocrine cells are dispersed diffusely throughout many organ systems in the body and hence neuroendocrine tumors (NETs) can arise from almost anywhere in the body. NETs are considered rare tumors, and the current incidence is reported to be about 6 cases in 100 000 in adults and about 2.8 cases per million in the pediatric age group. Despite the indolent nature of these tumors, they have the potential for metastasis and significant morbidity. NETs can be asymptomatic at the time of diagnosis or can present with flushing, diarrhea, wheezing, weight loss, and fatigue among other symptoms. Due to the ambiguity of presenting symptoms, it is not uncommon for NETs to be diagnosed late in the disease course. Despite low incidence, the prevalence of the disease is high since patients live for many years and sometimes decades. Early detection of well-differentiated NETs has excellent outcomes with the majority of early-stage diseases being cured with surgical resection alone. There have been recent advancements in the management of metastatic progressive NETs with approval of peptide receptor radionuclide therapy, telotristat, and everolimus. Awareness of these rare tumors and its management is crucial for optimal management. This article will focus on pediatric NETs and current advances in its management.

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.

Management and outcome of children with neuroendocrine tumors of the appendix in Spain: Is there room for improvement?

PURPOSE

Neuroendocrine tumors (NETs) are, after lymphomas, the most frequent gastrointestinal tumors in children, mainly located in the appendix. Best management remains unclear, given the absence of pediatric guidelines. We present the first Spanish series of pediatric patients with NETs.

PATIENTS AND METHODS

Retrospective study of all pediatric patients (<18 years) with NET treated in four oncology reference institutions in Spain between 1994 and 2015.

RESULTS

Seventeen patients were included. All patients presented with acute abdomen. TNM stage was T1a (82%) and T1b (12%). Extension study was heterogenous, with only 4 patients undergoing an OctreoScan. Four patients met criteria for second surgery (affected surgical margins or mesoappendix invasion), but it was only performed in two. Despite the diverse management, none of the patients relapsed during follow-up.

CONCLUSIONS

The disparity in diagnostic tests, second surgery criteria and follow-up shown in this study highlights the need for specific pediatric guidelines.

Well-differentiated neuroendocrine tumor of the stomach: A rare case at an uncommon site

INTRODUCTION

A 13-year-old African-American female presented to her primary care physician's office with fatigue, syncope, and hematemesis. After initial evaluation, the patient was referred to pediatric gastroenterology clinic for further evaluation.

MAIN CONCERNS, IMPORTANT FINDINGS

An upper gastrointestinal endoscopy was performed to evaluate the source of her bleeding. Endoscopy revealed a 3-cm mass in the lesser curvature of the stomach, and a biopsy of the mass revealed a concern for carcinoid (neuroendocrine) features.

DIAGNOSIS

She underwent an open gastrectomy. Post-surgical pathology reports confirmed a well-differentiated neuroendocrine tumor of the stomach.

CONCLUSION

Neuroendocrine tumors of the stomach in children are rare and we presently do not have pediatric-specific diagnostic and treatment guidelines. Although adult-based The North American Neuroendocrine Tumor Society (NANETS) guidelines are helpful, they are clearly not geared toward pediatric patients. To establish pediatric guidelines and to assess effectiveness of treatments, multicenter data collection is essential. In the long run, accumulation of clinically useful treatment information and long-term follow-up guidelines should enable clinicians to improve standard of care given to children with neuroendocrine tumors.

Metastasized pancreatic neuroendocrine tumor in a teenage girl: a case report

INTRODUCTION

Metastasized pancreatic neuroendocrine tumors are extremely rare malignancies, especially in children. Therefore, therapeutic options are limited, and few standardized therapy regimens exist.

CASE PRESENTATION

We report a case of a 14-year-old white girl. In 2011 she was diagnosed with a metastasized, well-differentiated pancreatic neuroendocrine tumor with expression of synaptophysin and chromogranin A. We describe her clinical course with special attention to her individual therapeutic regimens while bringing together several disciplines of medicine.

CONCLUSIONS

In patients such as ours, surgical intervention may be the only therapy that will lead to long-term survival.

A Comparison Between Appendiceal and Nonappendiceal Neuroendocrine Tumors in Children and Young Adults: A Single-institution Experience

BACKGROUND

Pediatric neuroendocrine tumors (NETs) are rare tumors. The purpose of this study is to report the clinical characteristics and outcomes of pediatric patients treated for NET at a single institution.

PROCEDURE

A retrospective record review.

RESULTS

There were 33 evaluable patients with median age of 17.9 years (range, 9.9 to 21.9 y) and predominantly females (58%). There were 17 patients with well-differentiated appendiceal NET, whereas 16 were nonappendiceal. Most common nonappendiceal sites were unknown primary (N=6) and pancreas (N=4). Majority of tumors were low grade (N=24, 73%) and small (T1, N=22, 67%). Nonappendiceal tumors were more likely to be larger or high-grade tumors (5/16, 31%), or with metastasis. All appendiceal NET patients underwent curative surgery. All patients who experienced treatment failure had nonappendiceal NET, despite prior chemotherapy in 8 of 9 patients. The 5-year overall survival rates for patients with appendiceal and nonappendiceal NET were 100% and 66% (95% CI, 45%-95%; P=0.006); and 5-year relapse-free survival rate for patients with appendiceal and nonappendiceal NET were 100% and 41% (95% CI, 22%-75%; P=0.002).

CONCLUSIONS

Well-differentiated appendiceal tumors were the most common pediatric NET and have an excellent prognosis. Better therapies are needed for patients with nonappendiceal NET.

Rare childhood cancers--an increasing entity requiring the need for global consensus and collaboration

Rare childhood cancers have not benefited to the same extent from the gains that have been made for their frequently occurring counterparts. In recent years, this gap has been recognized and a number of vehicles now exist to improve outcome, including rare tumor groups, disease-specific registries, and clinics. The multitude of approaches has allowed significant progress, however, this framework is limited by patient number and is not inclusive for every type of rare childhood cancer. These shortcomings can be overcome by a single global unified approach to the study of rare childhood tumors.

Appendiceal carcinoids in children--management and outcomes

BACKGROUND

Appendiceal carcinoid tumors are very rare in children, and management has been guided by adult presentations and outcomes. Here, we present our experience with pediatric appendiceal carcinoid tumors.

METHODS

We undertook a retrospective review of all cases of appendiceal carcinoids in children over a 20-y period. Data regarding clinical presentation, diagnosis, pathology, follow-up, and outcomes were collected and analyzed.

RESULTS

We identified 13 cases of appendiceal carcinoids. All cases were diagnosed after appendectomy for presumed appendicitis (nine acute and four interval;), with no patient having carcinoid syndrome. Mean age at diagnosis was 13.7 y, and all but one case was female. Tumor size ranged from microscopic foci of tumor cells to 2.1 cm (mean, 0.93 cm). Seven cases had invasion of the mesoappendix, three of which underwent a subsequent right hemicolectomy. The patient with the largest tumor (2.1 cm) had evidence of lymphatic invasion with three nodes positive for tumor after right colectomy. No patient had elevation of 5-hydroxyindoleacetic acid or serum chromogranin A, and surveillance computed tomographic scans did not reveal any liver metastases.

CONCLUSIONS

This is a relatively large series of carcinoids of the appendix in children. We found no evidence of carcinoid syndrome or metastatic disease in these cases other than lymphatic. The need for a secondary colectomy is perhaps questionable.

Is there a role for PET-CT and SPECT-CT in pediatric oncology?

During the last decade, hybrid imaging has revolutionized nuclear medicine. Multimodal camera systems, integrating positron emission tomography (PET) or single photon emission computed tomography (SPECT) with computed tomography (CT) now combine the contrast provided by tumor-avid radioactive drugs with the anatomic precision of CT. While PET-CT to a great extent has replaced single-modality PET in adult oncology, the use of PET-CT in children has been controversial, since even the lowest dose CT protocols adds approximately 2 mSv to the radiation dose of about 4 mSv from the PET-study with F-18-fluorodeoxyglucose (F-18-FDG). The article describes the current techniques used, discusses radiation doses and gives an overview of current indications for PET-CT and SPECT-CT in children. Hybrid imaging with a tumor-avid radioactive drug provides extremely high contrast between tumor and background tissues, while the CT component helps to locate the lesion anatomically. Currently both PET-CT and SPECT-CT play a role in pediatric oncology; PET-CT using F-18-FDG particularly for staging and follow-up of lymphoma and brain cancer, bone and soft tissue sarcomas; SPECT-CT with I-123-metaiodobenzylguanidine (MIBG) for tumors of the sympathetic nervous system such as neuroblastoma and pheochromocytoma while the remaining neuroendocrine tumors are imaged with radioactively labeled somatostatin analogues. To reduce radiation dose, a low-dose CT in combination with ultrasound and/or magnetic resonance imaging for the assessment of anatomy is often preferred.

Primary micro neuroendocrine tumor arising in a horseshoe kidney with cyst: report of a case and review of literature

Abstract

Neuroendocrine tumors are a heterogeneous group of neoplasms that arise from neuroendocrine cells. Primary renal neuroendocrine tumors are among the most unusual of all renal neoplasms, since neuroendocrine cells are not found within normal renal parenchyma. Here, a case of primary micro neuroendocrine tumor (about 4.7 mm*2 mm) arising in the horseshoe kidney with a cyst of a 45-year-old man was reported and a literature review was written.

Virtual Slides

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