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

Slow and Steady: A Slowly Progressing Neuroendocrine Tumor

Neuroendocrine tumors (NETs) are rare malignant tumors that arise from neuroendocrine cells throughout the body, most commonly in the gastrointestinal and respiratory tracts. We report a case of well-differentiated grade 2 NET with a computed tomography scan showing multiple liver lesions consistent with the liver lesions seen 11 years before diagnosis. This case highlights the possibility of an indolent or prolonged clinical course of metastatic NET with an unknown primary vs primary hepatic NET.

Small bowel neuroendocrine tumours - casting the net wide

PURPOSE OF REVIEW

Our aim is to provide an overview of small bowel neuroendocrine tumours (NETs), clinical presentation, diagnosis algorithm and management options. We also highlight the latest evidence on management and suggest areas for future research.

RECENT FINDINGS

Dodecanetetraacetic acid (DOTATATE) scan can detect NETs with an improved sensitivity than when compared with an Octreotide scan. It is complimentary to small bowel endoscopy that provides mucosal views and allows the delineation of small lesions undetectable on imaging. Surgical resection is the best management modality even in metastatic disease. Prognosis can be improved with the administration of somatostatin analogues and Evarolimus as second-line therapies.

SUMMARY

NETs are heterogenous tumours affecting most commonly the distal small bowel as single or multiple lesions. Their secretary behaviour can lead to symptoms, most commonly diarrhoea and weight loss. Metastases to the liver are associated with carcinoid syndrome.

The effect of long-acting somatostatin analogues on the uptake of [177Lu]Lu-HA-DOTATATE

PURPOSE

According to IAEA/EANM/SNMMI guidelines, long-acting somatostatin analogues (LA-SSAs) should be discontinued 4-6 weeks prior to peptide receptor radionuclide therapy (PRRT) to prevent somatostatin receptor saturation. The aim of this study was to determine the effect of continued use of long-acting SSAs during PRRT on the uptake of [177Lu]Lu-HA-DOTATATE on SPECT/CT.

METHODS

Consecutive patients with neuroendocrine tumours who were treated with PRRT receiving 7.4 GBq of [177Lu]Lu-HA-DOTATATE were included. Patients were divided into 3 groups: (1) control (LA-SSA stopped > 6 weeks prior to PRRT), or continued treatment with (2) long-acting octreotide < 6 weeks prior to PRRT, or (3) long-acting lanreotide < 6 weeks prior to PRRT. The uptake of [177Lu]Lu-HA-DOTATATE was quantified in healthy tissues (spleen, liver, kidneys, bone marrow) and tumour lesions on SPECT/CT performed 24 h after PRRT. A Mann-Whitney U test was used to determine differences in uptake between the long-acting octreotide and long-acting lanreotide groups compared to the control group.

RESULTS

Forty-two patients with 135 cycles of PRRT were included: 28 with lanreotide, 50 with octreotide, and 57 cycles without LA-SSAs. Uptake of [177Lu]Lu-HA-DOTATATE was significantly decreased in liver parenchyma in patients with lanreotide (p < 0.001) and in the spleen in patients with either octreotide or lanreotide (both p < 0.001). No differences were observed for uptake in kidneys, bone marrow, and blood pool. Uptake of [177Lu]Lu-HA-DOTATATE in tumours was the same in patients with lanreotide compared to the control (p = 0.862) and in patients with octreotide compared to the control (p = 0.201), independent of tumour location.

CONCLUSION

Long-acting octreotide and lanreotide do not interfere with the uptake of [177Lu]Lu-HA-DOTATATE in tumour lesions 24 h post-injection. Uptake in healthy liver parenchyma significantly decreases after lanreotide administration prior to PRRT, while uptake in healthy spleen tissue significantly decreases with both octreotide and lanreotide administration.

Gastrointestinal Neuroendocrine Tumours: A Single-Centre Experience

Objectives

Gastrointestinal neuroendocrine tumours (GI-NETs) are actually malignant tumours, and their most common location of metastasis is the liver. In this study, we define the epidemiologic features of NETs and investigate the demographic factors, clinicopathologic features, survival, and the oncologic results related to GI-NETs.

Materials and Methods

In this 10-year study (2009–2019), all GI and liver NETs were taken out from the pathology records. When classification based on the WHO classification criteria, patients were categorized based on their location, sex, age, and proliferative index. After studying clinical charts of GI-NET cases, a complete panel of IHC markers such as Chromogranin A, ‘Ki67’ and synaptophysin were used. Results: Based on published data, the liver is not a common primary site for NETs; most liver lesions are most likely to have been metastases. The mean age of patients at diagnosis was 52.72 years. In this research, 27.78% of patients had colon NETs and 27.78 liver. Two (11.11%) patients were classified as stage II, seven (38.89%) as stage III, and one (5.56%) as stage IV. After a 120-month follow-up, 13 (72.22%) patients with colorectal NETs were alive, and 5 (27.78%) of the patients had died.

Conclusion

Treatment of colon and rectal NETs is difficult because it affects the patient's initial site of involvement, and this often makes treatment difficult for the patient. With suitable management, the prognosis can be positive with long survival, but it is related to the tumour variation grade, the efficiency of the selected treatment, and also to the patient's adherence to the follow-up.

Ewing sarcoma of the ileum with wide multiorgan metastases: A case report and review of literature

BACKGROUND

Ewing sarcoma (ES) is an aggressive small round cell tumor that usually occurs in younger children and young adults but rarely in older patients. Its occurrence in elderly individuals is rare. ES of the ileum with wide multiorgan metastases is rarely reported and difficult to distinguish radiologically from other gastrointestinal tract tumors.

CASE SUMMARY

A 53-year-old man presented with right lower quadrant pain for 2 wk. Computed tomography results showed a heterogeneous mass within the ileum and widespread multiorgan metastases. This mass was biopsied, and pathological examination of the resected specimen revealed features consistent with an extraskeletal ES.

CONCLUSION

This case emphasizes the importance of recognizing this rare presentation in the small intestine to broaden the differential diagnosis of adult intraabdominal tumors.

Overview of microRNAs as liquid biopsy biomarkers for colorectal cancer sub-type profiling and chemoresistance

Colorectal cancer (CRC) is the third most common cancer worldwide. It has also been demonstrated that over the last ten years the incidence of CRC among younger people below the age of 50 is also increasing. Screening for colorectal cancer is of utmost importance; the rationale behind screening is to target the malignancy and reduce the incidence and mortality of the disease. Diagnostic methods to screen for incidence or relapse are therefore a requisite to detect cancer as early as possible. Scientific findings demonstrate that many deaths are due to lack of screening and therefore early identification will lead to greater survivability. In colorectal cancer, diagnostic tests include liquid biopsy biomarkers. Since the discovery of microRNAs (miRNAs), many studies have demonstrated the relationship between miRNAs and the various sub-types of CRC. Several miRNAs have been identified after analysing serum or plasma samples in patients, and such miRNAs were found to be significantly dysregulated. Such findings place the possibility of miRNAs to be at the epicentre of novel diagnostic techniques for CRC identification and sub-type stratification, including other characteristics associated with CRC development such as patient prognosis. The following review serves to underline the latest findings for miRNAs with such potential for routine diagnostic employment in CRC diagnostics and treatments.

A Patient with an Ileocecal MiNEN and a Synchronous Squamous Non-Small-Cell Lung Cancer: Case Report and Review of the Literature

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are rare tumors composed of two different histological components, one of which is of a neuroendocrine origin. Given its suggested underdiagnosis and consequent low prevalence, no clear diagnostic and treatment guidelines are available, and treatment usually follows regimens similar to that of the most aggressive component. On the other hand, multiple primary tumors (MPTs) are also rare neoplastic entities that usually confer a challenge regarding treatment options, for a regimen that comprises both the primary and the synchronous/metachronous malignancy should be used. Here, we discuss the challenging diagnostic and therapeutic management of a patient with an ileocecal MiNEN that presented along with a synchronous squamous non-small-cell lung cancer (SQ-NSCLC). The patient presented with intestinal obstruction symptoms for which he underwent an emergency resection of the ileocecal MiNEN. An initial CT scan showed an additional lung mass later identified as an SQ-NSCLC after bronchoscopy biopsy analysis. Given the rapid hepatic metastatic progression, palliative platinum-based chemotherapy was initiated, with an adequate response of the local and metastatic lesions of the MiNEN, but suggested platinum resistance and progression of the pulmonary neoplasm. Second-line treatment with pembrolizumab directed for the SQ-NSCLC was initiated; however, it was stopped after immune-mediated toxicities developed. A third-line chemotherapy scheme with carboplatin/gemcitabine was initiated, but central nervous system (CNS) progression developed, with the patient dying 11 months after initial diagnosis.

Incidence of Gastrointestinal Neuroendocrine Tumor: Case Series, Armed Forces Hospital Southern Region, Hospital-Based Tumor Board Registry

Neuroendocrine tumors are aggressive and rare tumors which can occur almost everywhere in the body. The annual incidence of neuroendocrine tumors is 2.5-5 per 100000. We report seven cases of gastrointestinal neuroendocrine tumors which were diagnosed and treated at our hospital from the time period of 2016-2018 knowing that the total number of our hospital tumor board cases registry during the same period was 444 cases.

Comprehensive Genomic Profiling of Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs)

PURPOSE

GEP-NENs are rare malignancies with increasing incidence. Their molecular characteristics are still undefined. We explored the underlying biology of GEP-NENs and the differences between gastrointestinal (GI) and pancreatic (PNEN), high-grade (HG), and low-grade (LG) tumors.

EXPERIMENTAL DESIGN

GEP-NENs were analyzed using next-generation sequencing (NGS; MiSeq on 47 genes, NextSeq on 592 genes), IHC, and in situ hybridization. Tumor mutational burden (TMB) was calculated on the basis of somatic nonsynonymous missense mutations, and microsatellite instability (MSI) was evaluated by NGS of known MSI loci.

RESULTS

In total, 724 GEP-NENs were examined: GI (N = 469), PNEN (N = 255), HG (N = 135), and LG (N = 335). Forty-nine percent were female, and median age was 59. Among LG tumors, the most frequently mutated genes were ATRX (13%), ARID1A (10%), and MEN1 (10%). HG tumors showed TP53 (51%), KRAS (30%), APC (27%), and ARID1A (23%). Immune-related biomarkers yielded a lower prevalence in LG tumors compared with HG [MSI-H 0% vs. 4% (P = 0.04), PD-L1 overexpression 1% vs. 6% (P = 0.03), TMB-high 1% vs. 7% (P = 0.05)]. Compared with LG, HG NENs showed a higher mutation rate in BRAF (5.4% vs. 0%, P < 0.0001), KRAS (29.4% vs. 2.6%, P < 0.0001), and PI3KCA (7% vs. 0.3%, P < 0.0001). When compared with GI, PNEN carried higher frequency of MEN1 (25.9% vs. 0.0%, P < 0.0001), FOXO3 (8.6% vs. 0.8%, P = 0.005), ATRX (20.6% vs. 2.0%, P = 0.007), and TSC2 (6.3% vs. 0.0%, P = 0.007), but lower frequency of mutations in APC (1.0% vs. 13.8%, P < 0.0001).

CONCLUSIONS

Significant molecular differences were observed in GEP-NENs by tumor location and grade, indicating differences in carcinogenic pathways and biology.

Clinical and pathological characteristics and prognosis of 132 cases of rectal neuroendocrine tumors

BACKGROUND

Neuroendocrine tumors (NETs) frequently occur in the gastrointestinal tract, lung, and pancreas, and the rectum and appendix are the sites with the highest incidence. Epidemiology statistics show that an estimated 8000 people every year in the United States are diagnosed with NETs occurring in the gastrointestinal tract, including the stomach, intestine, appendix, colon, and rectum. The pathological changes and clinical symptoms of NETs are not specific, and therefore they are frequently misdiagnosed.

AIM

To investigate the clinical symptoms, pathological characteristics, treatment, and prognosis of rectal neuroendocrine tumors (RNETs) by analyzing the clinical and pathological data of 132 RNET cases at our hospital.

METHODS

All RNETs were graded according to Ki-67 positivity and mitotic events. The tumors were staged as clinical stages I, II, III, and IV according to infiltrative depth and tumor size. COX proportional hazard model was used to assess the main risk factors for survival.

RESULTS

These 132 RNETs included 83 cases of G1, 21 cases of G2, and 28 cases of G3 (neuroendocrine carcinoma) disease. Immunohistochemical staining showed that 89.4% of RNETs were positive for synaptophysin and 39.4% positive for chromogranin A. There were 19, 85, 23, and 5 cases of clinical stages I, II, III, and IV, respectively. The median patient age was 52.96 years. The diameter of tumor, depth of invasion, and pathological grade were the main reference factors for the treatment of RNETs. The survival rates at 6, 12, 36, and 60 mo after operation were 98.5%, 94.6%, 90.2%, and 85.6%, respectively. Gender, tumor size, tumor grade, lymph node or distant organ metastasis, and radical resection were the main factors associated with prognosis of RNETs. Multivariate analysis showed that tumor size and grade were independent prognostic factors.

CONCLUSION

The clinical symptoms of RNETs are not specific, and they are easy to misdiagnose. Surgery is the main treatment method. The grade and stage of RNETs are the main indices to evaluate prognosis.

Gastrointestinal neuroendocrine tumors in 2020

Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological, biological, and clinical characteristics that have increased in incidence and prevalence within the last few decades. They contain chromogranin A, synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor. Ki-67 index and mitotic index correlate with cellular proliferation. Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors. Most of the gastrointestinal neuroendocrine tumors are non-functional. World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm. Gastric neuroendocrine tumors arise from enterochromaffin like cells. They are classified into 4 types. Only type I and type II are gastrin dependent. Small intestinal neuroendocrine tumor is the most common small bowel malignancy. More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve. Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs. Duodenal and jejuno-ileal neuroendocrine tumors are distinct biologically and clinically. Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver. Appendiceal neuroendocrine tumors are generally detected after appendectomy. Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis. Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000. Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy, endoscopic ultrasound, serology of biomarkers, imaging studies and functional somatostatin scans. Various treatment options are available for curative and palliative treatment of gastrointestinal neuroendocrine tumors.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Rare Location of a Neuroendocrine Tumor

Neuroendocrine tumors (NETs) arising in the duodenum are rare neoplasms that are often classified as indolent and have a low potential to metastasize. Although rare, multiple reports cite an increasing incidence of duodenal NETs. Symptoms are usually nonspecific and the diagnosis is made via endoscopy. Endoscopic resection is the mainstay of therapy. The prognosis is usually favorable. We describe a case of a duodenal NET that presented with vague symptoms in order to increase the awareness of this rare but increasing in frequency entity.

Infection with multidrug-resistant Campylobacter coli mimicking recurrence of carcinoid syndrome: a case report of a neuroendocrine tumor patient with repeated diarrhea

BACKGROUND

Campylobacteriosis caused by Gram-negative bacteria of the genus Campylobacter (mainly C. jejuni and C. coli) is one of the most common gastrointestinal zoonotic infections with increased incidence in humans worldwide. The typical symptoms are severe abdominal cramps, diarrhea and sometimes fever. The clinical course of Campylobacter infection is mainly mild and after one week self-limiting, but can take several weeks in some rare cases. However, patients with neuroendocrine tumors in the gastrointestinal tract, a neoplasm of enterochromaffin/neuroendocrine cell origin, can develop severe diarrhea during progression of tumor growth caused by hormonal excess due to the tumor. Both diseases have very similar clinical symptoms and this case report elaborates the differences. So far it is known in the literature that the clinical symptoms of campylobacteriosis can mimic appendicitis or acute colitis of inflammatory bowel disease but a mimicking of recurrence of carcinoid syndrome in a patient with neuroendocrine tumor is not reported.

CASE PRESENTATION

A 72-year-old man with already diagnosed and treated metastatic neuroendocrine tumor of the terminal ileum (G1 rated, Ki-67 index 1 %) was again suffering from increasing diarrhea, abdominal cramps and weight lost. These symptoms were similar to the initial symptoms due to the tumor which improved at the time after total resection of the primary in the terminal ileum and regular therapy with long-acting release depot octreotide intramuscularly. As progression/tachyphylaxis in symptomatic patients with carcinoid syndrome undergoing therapy, reassessment of disease and analysis of tumor markers was initiated, and the interval of intramuscular injections was shortened. Radiological findings and tumor marker levels disclosed no evidence of neuroendocrine tumor progression and the symptoms continued. After 4 weeks with symptoms the patient developed additionally fever. Due to impaired renal function and elevated signs of systemic inflammation fluid replacement and empiric antimicrobial therapy were started. At this time-point the first stool cultures were taken which disclosed an infection with C. coli. The empiric antimicrobial therapy was stopped after five days because of multidrug-resistant isolated strain. During the ongoing symptomatic therapy the patient becomes gradually symptom-free 6 weeks later, resulting a total duration of symptoms caused by campylobacteriosis of 13 weeks.

CONCLUSION

This case of infection with C. coli mimicking recurrence of carcinoid syndrome suggests that assessment for bacterial gastrointestinal infections should be taken into account also in patients with neuroendocrine tumors who present worsening of their symptoms in spite of initially successful management. The duration of symptoms caused by campylobacteriosis were significantly extended which might be due to gastroenteric dysfunctions/mucosal changes caused by the carcinoid syndrome in this patient.

Update on medical treatment of small intestinal neuroendocrine tumors

INTRODUCTION

Small intestinal (SI) neuroendocrine tumors (NETs) are relatively rare tumors. Due to the lack of symptom or specific symptoms, SI-NETs are often diagnosed at an advanced stage, making therapy challenging. The management of patients with advanced stage SI-NETS requires a multidisciplinary approach that combines surgical and medical treatment including novel targeted molecular therapies.

AREAS COVERED

This article summarizes current strategies for the medical treatment of SI-NETS. Expert commentary: The treatment plan of advanced-stage SI-NETs should be tailored in a case-by-case manner with the adoption of a multidisciplinary approach that combines different treatment options, including biological targeted therapies. In particular, we believe that the identification of the optimal treatment sequence(s), correct treatment timing and the selection of patients eligible to different treatments need specific investigation in controlled clinical trials.

Giant type III well-differentiated neuroendocrine tumor of the stomach: A case report

INTRODUCTION

We describe a case of a large type III neuroendocrine tumor of the stomach. Management and current literature are reviewed.

PRESENTATION OF CASE

A 37year old female presented with upper gastrointestinal bleed and epigastric pain. Further workup demonstrated a large ulcerated gastric mass near the GE junction. Computer tomography scan and endoscopic ultrasound showed a 10cm mass with no evidence of distant disease. Fine needle aspiration pathology was consistent with a well differentiated neuroendocrine tumor (Ki67 index<2%), with elevated levels of chromogranin A and serotonin levels but normal gastrin. The patient underwent an uneventful total gastrectomy. Final pathology analysis reported a higher KI67 index (7.54%) and a final pathology of grade 2 type III, T3 N3, neuroendocrine tumor of the stomach. The chromogranin levels normalized and no recurrent disease has been detected in one year follow up.

DISCUSSION

Gastric neuroendocrine tumors are extremely rare, accounting for 4% of all neuroendocrine tumors of the body and 1% of all neoplasms of the stomach. Based on histomorphologic characteristics and pathogenesis, gastric neuroendocrine tumors are classified into four types with differing prognosis and behavior. Current literature describes type 3 gastric neuroendocrine tumors as larger than 2cm. However, there is no precedent in the literature for a tumor of this size.

CONCLUSION

The incidence of gastric neuroendocrine tumors has been increasing during the last decade, underscoring the need to improve our understanding of their biology and behavior. When identified histologically, patient outcomes depend on appropriate determination of tumor biology and subsequent choice of treatment.

Chronic intermittent abdominal pain in young woman with intestinal malrotation, Fitz-Hugh-Curtis Syndrome and appendiceal neuroendocrine tumor: a rare case report and literature review

Background

There are a lot of different causes of abdominal pain; in this case, a young woman suffers from three diseases with similar symptoms. Adult intestinal mal-rotation is a rare condition of deviation from the normal 270° counter clockwise rotation of the midgut resulting in, not only mal-position of the small intestine, but also mal-fixation of the mesentery. Fitz-Hugh-Curtis syndrome is a rare complication of pelvic inflammatory disease; it involves liver capsule inflammation associated with genital tract infection, which is usually caused by Neisseria gonorrhoea and Chlamydia trachomatis. Neuroendocrine tumors are enterochromaffin cell neoplasms that arise from cells of the endocrine (hormonal) and nervous systems; the appendicular one is the most common primary malignant lesion of these tumors, it’s incidence is about 0.3 – 0.9 % of appendectomies done. Just for knowledge, this is the first described case of concomitant presence of all these diseases with clinical symptoms attributable to each one.

Case presentation

40-years-old woman suffers from acute abdominal pain, predominantly on the right quadrants, without abdominal distension, no guarding nor rigidity and normal intestinal peristalsis. She has a long history of abdominal intermittent pain, with cramps every 30–40 min, resolving spontaneously. She was diagnosed as intestinal mal-rotation through computed tomography scan which has evidenced a mobilized intra - peritoneal duodenum with cecum/ascending colon predominately lying on the left side and the small intestine almost entirely lying on the right side of abdomen, without evidence of effusion, edema or signs of intestinal ischemia or infarction. Exploratory laparoscopy demonstrated an inflammatory process in the hepatic-renal space, with bloody adhesions above the liver capsule; this is additional to the typical pelvic inflammatory disease signs (Fitz-Hugh-Curtis syndrome). Appendectomy was performed with histological analysis resulting in appendicular neuroendocrine tumor.

Conclusions

Although the patient has an intestinal mal-rotation which could explain the abdominal painful symptoms, it is not possible to exclude other concomitant causes, such as perihepatitis on pelvic inflammatory disease or neuroendocrine tumors. Even if all these diseases are rarely seen in daily clinical practice, they should be considered in the differential diagnosis of chronic intermittent abdominal pain in a young woman.

Retrospective analysis of the clinicopathological characteristics of gastrointestinal neuroendocrine neoplasms

The aim of the present study was to analyze and summarize the clinicopathological characteristics and factors affecting prognosis for patients with gastrointestinal neuroendocrine neoplasms (GINENs). Retrospective analysis was conducted on the clinicopathological data of 74 patients who were diagnosed with GINEN, and immunohistochemical methods were used to detect the expression levels of relevant markers [synaptophysin (Syn), chromogranin A (CgA) and Ki-67]. Among the 74 cases with GINEN, there were 39 males and 35 females, with an average age of 56.9 years. There were 32 neoplasms in the rectum, 29 in the stomach, 6 in the colon, 2 in the small intestine and 5 in the appendix. All 74 cases underwent surgical resection. According to the World Health Organization Classification of Tumors of the Digestive System (2010), the diagnosis of the 74 cases showed 41 cases (55.4%) of neuroendocrine tumor (NET; 25 cases of G1 and 16 cases of G2), 21 cases (28.4%) of neuroendocrine carcinoma (NEC) and 12 cases (16.2%) of mixed adenoneuroendocrine carcinoma (MANEC). Additionally, 19 cases had metastasis to lymph nodes. During 10-34 months of follow-up, 15 patients had distant metastasis and 24 patients succumbed, and the accumulative survival rate in 1 or 2 years was 87.8 and 74.3%, respectively. Six factors, namely neoplasm size, depth of invasion, lymph node metastasis, distant metastasis, pathological type and the expression or lack of expression of CgA, significantly affected the survival time of patients. Definitive diagnosis of GINEN mainly relies on pathological diagnosis. GINENs with different histopathological types and grading have different clinicopathological characteristics and prognosis: NETs are mainly early lesions with a good prognosis, whereas NECs and MANECs have high malignancy and strong invasion with a worse prognosis.

Diagnosing and treating neurogenic orthostatic hypotension in primary care

In response to a change in posture from supine or sitting to standing, autonomic reflexes normally maintain blood pressure (BP) by selective increases in arteriovenous resistance and by increased cardiac output, ensuring continued perfusion of the central nervous system. In neurogenic orthostatic hypotension (NOH), inadequate vasoconstriction and cardiac output cause BP to drop excessively, resulting in inadequate perfusion, with predictable symptoms such as dizziness, lightheadedness and falls. The condition may represent a central failure of baroreceptor signals to modulate cardiovascular function, a peripheral failure of norepinephrine release from cardiovascular sympathetic nerve endings, or both. Symptomatic patients may benefit from both non-pharmacologic and pharmacologic interventions. Among the latter, two pressor agents have been approved by the US Food and Drug Administration: the sympathomimetic prodrug midodrine, approved in 1996 for symptomatic orthostatic hypotension, and the norepinephrine prodrug droxidopa, approved in 2014, which is indicated for the treatment of symptomatic neurogenic orthostatic hypotension caused by primary autonomic failure (Parkinson's disease, multiple system atrophy and pure autonomic failure). A wide variety of off-label options also have been described (e.g. the synthetic mineralocorticoid fludrocortisone). Because pressor agents may promote supine hypertension, NOH management requires monitoring of supine BP and also lifestyle measures to minimize supine BP increases (e.g. head-of-bed elevation). However, NOH has been associated with cognitive impairment and increases a patient's risk of syncope and falls, with the potential for serious consequences. Hence, concerns about supine hypertension - for which the long-term prognosis in patients with NOH is yet to be established - must sometimes be balanced by the need to address a patient's immediate risks.

Metastatic extrapulmonary small cell carcinoma to the cerebellopontine angle: a case report and review of the literature

Extrapulmonary small cell carcinomas (EPSCC) are rare malignancies with poor patient prognoses. We present the case of a 63-year-old male who underwent surgical resection of a poorly differentiated small cell carcinoma, likely from a small intestinal primary tumor that metastasized to the cerebellopontine angle (CPA). A 63-year-old male presented with mild left facial paralysis, hearing loss, and balance instability. MRI revealed a 15 mm mass in the left CPA involving the internal auditory canal consistent with a vestibular schwannoma. Preoperative MRI eight weeks later demonstrated marked enlargement to 35 mm. The patient underwent a suboccipital craniectomy and the mass was grossly different visually and in consistency from a standard vestibular schwannoma. The final pathology revealed a poorly differentiated small cell carcinoma. Postoperative PET scan identified avid uptake in the small intestine suggestive of either a small intestinal primary tumor or additional metastatic disease. The patient underwent whole brain radiation therapy and chemotherapy and at last follow-up demonstrated improvement in his symptoms. Surgical resection and radiotherapy are potential treatment options to improve survival in patients diagnosed with NET brain metastases. We present the first documented case of skull base metastasis of a poorly differentiated small cell carcinoma involving the CPA.

A cause to consider for chronic unresolving diarrhea

A 36-year-old male who carried a diagnosis of irritable bowel syndrome presented with chronic watery diarrhea and was found to have hepatomegaly on physical exam. A computed tomography (CT) scan of the abdomen revealed hepatomegaly with lesions suspicious for metastatic disease. A colonoscopy revealed a polypoid lesion in the terminal ileum, which was biopsied, revealing a neuroendocrine tumor (NET). He was treated with palliative octreotide and chemoembolization of liver metastases until disease progression. The case highlights the importance of considering functional NETs, especially carcinoid syndrome, in patients with chronic unresolving diarrhea, since early diagnosis allows for further treatment options that can prolong survival.