Unresectable Mesenteric Mass Causing Small Bowel Obstruction

Small bowel obstruction (SBO) has a variety of etiologies, including but not limited to adhesions, malignancy, hernia, and inflammatory bowel diseases. Treatment for SBO may be nonoperative or operative, depending on the underlying condition and clinical symptoms. Clinical judgment and radiological findings cooperate in formulating an appropriate assessment and treatment plan. Mass effect due to malignancy is an indication for surgical intervention, as tumor resection is a mainstay of treatment. However, patient safety and chances of vascular compromise must be considered when determining if the tumor is resectable. Reported is a case of a 65-year-old female with severe abdominal pain, nausea, vomiting, and obstipation due to a malignant neuroendocrine tumor within the mesentery adjacent to the aortic bifurcation. Management included surgical intervention to alleviate bowel obstruction and biopsy of the tumor.

Clinicopathological Features of Primary Neuroendocrine Tumors of Gastrointestinal/Pancreatobiliary Tract With Emphasis on High-Grade (Grade 3) Well-Differentiated Neuroendocrine Tumors

Introduction

The two broad subcategories of neuroendocrine neoplasms (NENs) are well-differentiated neuroendocrine tumors (WDNETs) and poorly differentiated neuroendocrine carcinomas (PDNECs), based on tumor architecture and cytology. Grade 3 WDNETs are a subset of WDNETs that not only are high grade by mitotic activity or proliferative index but exhibit a well-differentiated histology. In this study, we evaluated the clinicopathological features of primary neuroendocrine tumors of the gastrointestinal (GI)/pancreatobiliary tract with emphasis on high-grade WDNETs, as it is a newly defined entity.

Methods

We conducted a retrospective observational study, including a total number of 122 cases of primary GI and pancreatobiliary tract NENs. Slides and blocks of all cases were retrieved from the departmental archives. Immunohistochemical stains including Ki67 were applied to selected tissue blocks of all cases. Tumors were then evaluated for their histological differentiation and tumor grade.

Results

Our results showed that the mean age of patients was 46.8 ± 17.1 years. Majority of the NENs were GI tract origin (86.9%). The most common site of tumor in gastroenteropancreatic tract was the small bowel (31.1%), followed by the stomach (26.2%). Ninety five percent of the tumors were WDNETs, of which the most common grade was G2. The mean Ki67 index was 15.8 ± 23.8. Grade 3 WDNETs were noted to have an older mean age than grades 1 and 2 WDNETs. Ten out of 102 (9.8%) WDNETs of GI tract were grade 3, compared with four out of 14 (28.6%) of pancreatobiliary tract. 

Conclusion

In this study, we found that high-grade (grade 3) WDNETs were more frequent in pancreatobiliary tract than GI tract. Moreover, high-grade WDNETs were associated with a higher mean age than low-grade (grade 1-2) WDNETs. It is extremely important to recognize this subset (high grade) of WDNETs and to distinguish it from PDNECs, as the latter are known to be associated with a worse overall survival. Despite high mitotic rate/proliferative index, high-grade WDNETs are characterized by organoid architecture and monomorphic cell population.

When Adenocarcinoma Went Hand in Hand with Neuroendocrine Tumor: A Rare Case of Adenocarcinoma Synchronous with Neuroendocrine Tumor in Ampulla of Vater

Neuroendocrine tumors (NETs) of gastrointestinal tract are rare entities. Their presence as synchronous lesions with adenocarcinoma has rarely been described in the literature. Cases of synchronous lesions of adenocarcinoma with neuroendocrine component have been described in the colon in the past. However, synchronous presence in the ampulla of Vater is quite uncommon. In the duodenum, NETs constitute 5.7 to 7.9% of the neuroendocrine neoplasms of the gastroenteropancreatic tract. We present a case of 65-year-old male who presented with abdominal symptoms and weight loss, was found to have adenocarcinoma of the ampulla of Vater on biopsy via endoscopic retrograde cholangiopancreatography (ERCP), for which he underwent Whipple’s surgery and was found to have neuroendocrine component along with adenocarcinoma postoperatively on histology.

Carcinoid Tumor Arising from the Sphenoid Sinus Treated with Definitive Intensity-modulated Radiation Therapy: A Case Report

Head and neck neuroendocrine tumors (NET) are a rare type of cancer. NET can be classified according to the histopathological features. The typical carcinoid tumor is a well-differentiated tumor that is the least common among other types. Owing to its indolent behavior and variable radiological and pathological features, treatment of carcinoid tumors remains a challenge. We report a case of a 54-year-old man presenting with a non-operable carcinoid tumor arising in the sphenoid sinuses treated with radiotherapy with stable disease control after three years follow-up.

Menin and Daxx Interact to Suppress Neuroendocrine Tumors through Epigenetic Control of the Membrane Metallo-Endopeptidase

Neuroendocrine tumors (NET) often harbor loss-of-function mutations in the MEN1 and DAXX tumor suppressor genes. Here, we report that the products of these genes, menin and Daxx, interact directly with each other to suppress the proliferation of NET cells, to a large degree by inhibiting expression of the membrane metallo-endopeptidase (MME). Menin and Daxx were required to enhance histone H3 lysine9 trimethylation (H3K9me3) at the MME promoter, as mediated partly by the histone H3 methyltransferase SUV39H1. Notably, the menin T429K mutation associated with a NET syndrome reduced Daxx binding, MME repression, and proliferation of NET cells. Conversely, inhibition of MME in NET cells repressed proliferation and tumor growth in vivo Our findings reveal a previously unappreciated cross-talk between two crucial tumor suppressor genes thought to work by independent pathways, focusing on MME as a common target of menin/Daxx to treat NET. Cancer Res; 77(2); 401-11. ©2016 AACR.

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.

Pancreatic neuroendocrine tumors: clinical features, diagnosis and medical treatment: advances

Pancreatic neuroendocrine tumors (pNETs) comprise with gastrointestinal carcinoids, the main groups of gastrointestinal neuroendocrine tumors (GI-NETs). Although these two groups of GI-NETs share many features including histological aspects; over-/ectopic expression of somatostatin receptors; the ability to ectopically secrete hormones/peptides/amines which can result in distinct functional syndromes; similar approaches used for tumor localization and some aspects of treatment, it is now generally agreed they should be considered separate. They differ in their pathogenesis, hormonal syndromes produced, many aspects of biological behaviour and most important, in their response to certain anti-tumour treatment (chemotherapy, molecular targeted therapies). In this chapter the clinical features of the different types of pNETs will be considered as well as aspects of their diagnosis and medical treatment of the hormone-excess state. Emphasis will be on controversial areas or recent advances. The other aspects of the management of these tumors (surgery, treatment of advanced disease, tumor localization) are not dealt with here, because they are covered in other chapters in this volume.