Islet cell tumor and a syndrome of refractory watery diarrhea and hypokalemia

Contemporary Approaches to the Surgical Management of Pancreatic Neuroendocrine Tumors

The incidence of pancreatic neuroendocrine tumors (PNETs) is on the rise primarily due to the increasing use of cross-sectional imaging. Most of these incidentally detected lesions are non-functional PNETs with a small proportion of lesions being hormone-secreting, functional neoplasms. With recent advances in surgical approaches and systemic therapies, the management of PNETs have undergone a paradigm shift towards a more individualized approach. In this manuscript, we review the histologic classification and diagnostic approaches to both functional and non-functional PNETs. Additionally, we detail multidisciplinary approaches and surgical considerations tailored to the tumor's biology, location, and functionality based on recent evidence. We also discuss the complexities of metastatic disease, exploring liver-directed therapies and the evolving landscape of minimally invasive surgical techniques.

Chronic Diarrhea Caused by Vasoactive Intestinal Peptide-Secreting Tumor

VIPomas are a type of neuroendocrine tumor that independently produces vasoactive intestinal peptide (VIP). VIPomas causing watery diarrhea, hypokalemia, and achlorhydria (WDHA) syndrome are not frequently observed in adult patients without pancreatic ailments. However, in children, the occurrence of a VIPoma originating in the pancreas is exceedingly uncommon. Instead, WDHA syndrome is more commonly associated with neurogenic tumors that secrete VIP, often located in the retroperitoneum or mediastinum. Among infants, chronic diarrhea is a prevalent issue that often necessitates the attention of pediatric gastroenterologists. The underlying causes are diverse, and delays in arriving at a definitive diagnosis can give rise to complications affecting the overall well-being of the child. The authors present the case of an infant with chronic watery diarrhea, subocclusion manifestations, mild hypokalemia, and metabolic hyperchloremic acidosis secondary to a VIPoma in the retroperitoneum that was diagnosed via abdominal ultrasound and tomography. The laboratory results revealed lowered potassium levels and an excessive secretion of VIP. Following the surgical removal of the tumor, the diarrhea resolved, and both electrolyte levels and the imbalanced hormone levels returned to normal. Immunohistochemical examination confirmed the diagnosis of ganglioneuroblastoma, with N-MYC negative on molecular biology tests. We present the clinical and histo-genetic aspects of this rare clinical entity, with a literature review.

Surgical Management of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are relatively uncommon malignancies, characterized as either functional or nonfunctional secondary to their secretion of biologically active hormones. A wide range of clinical behavior can be seen, with the primary prognostic indicator being tumor grade as defined by the Ki67 proliferation index and mitotic index. Surgery is the primary treatment modality for PNETs. While functional PNETs should undergo resection for symptom control as well as potential curative intent, nonfunctional PNETs are increasingly managed nonoperatively. There is increasing data to suggest small, nonfunctional PNETs (less than 2 cm) are appropriate follow with nonoperative active surveillance. Evidence supports surgical management of metastatic disease if possible, and occasionally even surgical management of the primary tumor in the setting of widespread metastases. In this review, we highlight the evolving surgical management of local and metastatic PNETs.

A clinical analysis on functioning pancreatic neuroendocrine tumors (focusing on VIPomas): a single-center experience

VIPomas are generally rare functioning pancreatic neuroendocrine tumors (PanNETs) that cause watery diarrhea, hypokalemia, and achlorhydria. Due to their extreme rarity, the clinicopathological features and outcomes of VIPomas have not been well reported. This study aimed to determine the diagnostic and therapeutic characteristics and prognosis of VIPomas and to compare them with other PanNETs at a Japanese reference hospital. Medical records of 293 patients with PanNETs were collected. Patient and tumor characteristics and outcomes were retrospectively reviewed. This cohort had only 1.4% (four patients) of patients with VIPomas, and three of these patients changed from non-functioning (NF-) PanNETs during their disease course. Recurrences of hormonal symptoms were observed in all patients despite the initial controls, and all of them died from their disease, more specifically mainly from hormonal symptoms. Compared to the other PanNETs, VIPomas were all located at the pancreatic tail, were larger, and had a higher Ki-67 index and more metastasis. The median survival time was significantly shorter for patients with VIPoma than for those with NF-PanNET (5.9 vs. 26.7 years, p < 0.0001), insulinoma (21.8 years, p < 0.0001), and gastrinoma (12.3 years, p = 0.0325). This study presents the possibility of shifting from non-symptomatic to symptomatic VIPomas as they grow or of transforming from NF-PanNETs to VIPomas. VIPomas should be considered in patients with relatively large NF-PanNETs, especially those located in the pancreatic tail, when diarrhea is continuously observed. As hormonal symptoms are an important cause of death in VIPomas, long-term symptomatic control, which is relatively difficult, is of great significance.

Treatment options of metastatic and nonmetastatic VIPoma: a review

PURPOSE

VIPoma belongs to the group of neuroendocrine neoplasms. These tumours are located mostly in the pancreas and produce high levels of vasoactive intestinal peptide (VIP). In most cases, a metastatic state has already been reached at the initial diagnosis, with high levels of VIP leading to a wide spectrum of presenting symptoms. These symptoms include intense diarrhoea and subsequent hypopotassaemia but also cardiac complications, with life-threatening consequences. Treatment options include symptomatic therapy, systemic chemotherapy and targeted therapy, as well as radiation and surgery. Due to the low incidence of VIPoma, there are no prospective studies or evidence-based therapeutic standards to date.

METHODS

To evaluate the possible impact of different therapy strategies, we performed literature research using PubMed.

RESULTS

All possible treatment modalities for VIPoma have at least one of two therapy goals: antisecretory effects (symptom control) and antitumoural effects (tumour burden reduction). Symptomatic therapy is the most important in the emergency setting to rehydrate, balance electrolytes and stabilise the patient. Symptomatic therapy is also of great importance perioperatively. Somatostatin analogues play a major role in symptom control, although their efficiency is often limited. Chemotherapy may be effective in reaching stable disease for a certain time period, although its impact on symptom control is limited and often delayed. Among targeted therapy options, the usage of sunitinib appears to be the most effective in terms of symptom control and showing antitumoural effects at the same time. Experience with radiation is still limited; however, local ablative procedures seem to be promising options. Peptide receptor radiotherapy (PRRT) with radiolabelled somatostatin analogues (SSAs, 177Lu-DOTATATE) offers a targeted approach, especially in patients with high somatostatin receptor density. Surgery is the first-line therapy for nonmetastatic VIPoma. Additionally, if the resection of all visible tumour lesions is possible, the surgical approach seems preferable to other strategies in highly symptomatic patients. The role of surgery in very advanced stages where only tumour debulking is possible remains debatable. However, a high rate of immediate symptom control can be achieved by tumour debulking followed by somatostatin therapy, although the impact on survival remains unclear.

CONCLUSION

Surgery is the only curative option for nonmetastatic VIPoma. Additionally, surgery should be a first-line therapy option for highly symptomatic patients, especially if the resection of all tumour lesions (primary tumour and metastasis) is achievable. In frail patients, other modalities can be used.

Metastatic mixed VIPoma/PPoma-induced diarrhoea causing renal failure

Summary

Vasoactive intestinal peptide-secreting tumours (VIPomas) are an extremely rare form of functional pancreatic neuroendocrine tumour with an estimated annual incidence of 1 in 10 million. Associated tumour hypersecretion of other peptides, including pancreatic polypeptide (PPomas), may also be seen. These malignancies classically present with a defined triad of refractory diarrhoea, hypokalaemia and metabolic acidosis known as Verner-Morrison syndrome. Diagnosis is frequently delayed, and the majority of patients will have metastatic disease at presentation. Symptoms are usually well controlled with somatostatin analogue administration. Here we report a case of metastatic mixed VIPoma/PPoma-induced diarrhoea causing renal failure so severe that ultrafiltration was required to recover adequate renal function.

Learning points

Profuse, watery diarrhoea is a common presenting complaint with a multitude of aetiologies. This, combined with the rarity of these tumours, makes diagnosis difficult and frequently delayed. A functional neuroendocrine tumour should be suspected when diarrhoea is unusually extreme, prolonged and common causes have been promptly excluded. These patients are likely to be profoundly unwell on presentation. They are extremely hypovolaemic with dangerous electrolyte and metabolic abnormalities. Aggressive initial rehydration and electrolyte replacement are imperative. A somatostatin analogue should be commenced as soon as the diagnosis is suspected. This is an extreme example of Verner-Morrison syndrome. We are unaware of another case where renal failure secondary to diarrhoea and dehydration was so severe that renal replacement therapy was required to restore adequate renal function, further emphasising how critically unwell these patients can be. Both the primary tumour and metastases showed a remarkably good and rapid response to somatostatin analogue administration. Cystic change and involution were noted on repeat imaging within days. Prior to his illness, this patient was extremely high functioning with no medical history. His diagnosis was an enormous psychological shock, and the consideration and care for his psychological well-being were a crucial part of his overall management. It highlights the importance of a holistic approach to cancer care and the role of the clinical nurse specialist within the cancer multidisciplinary team.

Vasoactive intestinal peptide secreting tumour: An overview

Vasoactive intestinal peptide (VIP) secreting tumour (VIPoma) is a rare functional neuroendocrine tumour that typically arises from pancreatic islet cells. These present as sporadic, solitary pancreatic neoplasias with an estimated incidence of one in ten million individuals per year. Only around 5% of VIPomas are associated with multiple endocrine neoplasia type I syndrome. Excessive VIP secretion produces a clinical syndrome characterized by refractory watery diarrhoea, hypokalemia and metabolic acidosis. These coupled with elevated plasma levels of VIP are diagnostic. The majority of VIPomas are malignant and have already metastasized at the time of diagnosis (60%). Metastases occur most frequently in the liver, or regional lymph nodes, lungs, kidneys and bones. Some reports of skin metastases have been documented. Complete surgical resection continues to be the only potentially curative treatment. However, when the neoplasia cannot be excised completely, surgical debulking may provide palliative benefit. Other palliative options have included recently the peptide receptor radionuclide therapy which has shown to be effective and well-tolerated. This article will review all aspects of pancreatic VIPomas highlighting aspects such as clinical presentation, diagnosis and management.

An update on the diagnosis of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) arise from neuroendocrine cells found throughout the gastrointestinal tract and islet cells of the pancreas. The incidence and prevalence of GEP-NENs have been increasing each year due to higher awareness, improved diagnostic modalities, and increased incidental detection on cross-sectional imaging and endoscopy for cancer screening and other conditions and symptoms. GEP-NENs are a heterogeneous group of tumors and have a wide range in clinical presentation, histopathologic features, and molecular biology. Clinical presentation most commonly depends on whether the GEP-NEN secretes an active hormone. The World Health Organization recently updated the classification of GEP-NENs to introduce a distinction between high-grade neuroendocrine tumors and neuroendocrine carcinomas, which can be identified using histology and molecular studies and are more aggressive with a worse prognosis compared to high-grade neuroendocrine tumors. As our understanding of the biology of GEP-NENs has grown, new and improved diagnostic modalities can be developed and optimized. Here, we discuss clinical features and updates in diagnosis, including histopathological analysis, biomarkers, molecular techniques, and radiology of GEP-NENs. We review established diagnostic tests and discuss promising novel diagnostic tests that are currently in development or require further investigation and validation prior to broad utilization in patient care.

Vasoactive Intestinal Peptide-Secreting Pancreatic Neuroendocrine Tumor: A Case Report

A 36-year-old female with chronic watery diarrhea and persistent hypokalemia for more than eight months duration eventually being diagnosed as vasoactive intestinal peptide tumor (VIPoma) clinically and histologically is presented here. The patient achieved complete recovery after starting octreotide, a somatostatin analog. She underwent a distal pancreatectomy along with the removal of the tumor at Teaching Hospital Jaffna for the permanent cure.

Long-term treatment with streptozocin/5-fluorouracil chemotherapy in patients with metastatic pancreatic neuroendocrine tumors: Case series

RATIONALE

Pancreatic neuroendocrine tumors (pNETs) are rare entities representing 1% to 3% of all malignant pancreatic neoplasms. Current guidelines recommend a combination of streptozocin (STZ) and 5-fluorouracil (5-FU) for patients with metastatic well-differentiated pNETs requiring systemic therapy. The highest median progression-free survival rate reported in previous studies for this combination was 23 months (95% confidence interval 14.5-31.5). However, it remains unclear for how long this regimen can be safely administered.

PATIENT CONCERNS

We report about 3 therapy-naïve patients with metastatic G2 (Ki67 10%-15%) pNETs treated with STZ/5-FU, that achieved sustained disease control for longer than 36 months.

DIAGNOSIS

Metastatic, well-differentiated G2 pNETs.

INTERVENTIONS

Systemic chemotherapy with STZ/5-FU was administered until the disease progressed. In 1 case showing a mixed response, selected metastases of increasing size were additionally treated with surgery and brachytherapy.

OUTCOMES

In our 3 patients with metastatic G2 pNETs, STZ/5-FU induced long-term disease control over 44, 42, and 95 months, respectively. No side effects that led to treatment discontinuation were observed.

LESSONS

In patients with metastatic G2 pNETs achieving disease control, STZ/5-FU can be safely administered.

The 100 most cited articles on pancreatic neuroendocrine tumors from 2000 to 2020: a bibliometric analysis

PURPOSE

The present study attempted to identify 100 most cited articles on pancreatic neuroendocrine tumors and characterize them via bibliometric analysis whereby it would provide an insight into the progress and trend in this field.

METHODS

Records regarding pancreatic neuroendocrine tumors and published between 2000 and 2020 were retrieved in 2021 through the Web of Science to identify the 100 most cited articles.

RESULTS

The 100 articles were screened in 17 434 records. The number of citations of the top-cited articles ranged from 151 to 1867. These articles were published in 47 journals among which the Journal of Clinical Oncology produced the most articles (n = 10). The USA contributed most of the articles (n = 44). Articles enrolled came from 58 institutions; the University of California System of the USA came to the top (n = 7). More than half of the articles were clinical studies (n = 55), basic science research reports accounting for a quarter. In clinical topics (n = 73), treatment issues were the most concerned (n = 21), in which more articles focused on targeted inhibitors. Articles about gene mutation were cited most frequently in basic science topics (n = 27).

CONCLUSIONS

This bibliometric analysis reflected the brief the progress and highlighted current trend in pancreatic neuroendocrine tumor research, providing references for further study.

Surgical treatment of metastatic VIPoma: a case report

VIPoma, a neuroendocrine tumour mostly occurring in the human pancreas and producing high levels of vasoactive intestinal peptide, is a rare disease that presents with a wide spectrum of symptoms, including intense diarrhoea, hypokalaemia, and cardiac complications, with life-threatening consequences. In most cases, metastatic lesions are present at VIPoma diagnosis. Treatment options include symptomatic therapy, chemotherapy, radiation and surgery. Due to its low incidence, there are no evidence-based therapy recommendations to date. Here, we present a case of a 39-year-old woman with severe symptoms due to VIPoma of the pancreas with diffuse hepatic metastasis, who underwent simultaneous resection of the primary tumour, extensive liver resection and radiofrequency ablation. The patient was released in good health and was recurrence-free during 12 months surveillance. According to the existing literature and our own experience, surgical procedures appear to be the most promising therapy option for cases with diffuse hepatic metastasis, offering patients relief from their symptoms and (chemo)therapy-free time.

Efficacy of treatments for VIPoma: A GTE multicentric series

BACKGROUND

Vasoactive intestinal peptide-secreting tumor (VIPoma) is a very rare, life-threatening, functioning pancreatic neuroendocrine tumor (pNET). The efficacy of antitumor therapies against functioning symptoms and tumor burden have been poorly described in VIPoma.

OBJECTIVE

Describe the impact of treatments on the secretory syndrome, tumor burden and survival in patients with VIPoma.

METHODS

We retrospectively reviewed the records of patients with VIPoma treated in seven French expert centers between 1990 and 2016. Diagnostic of VIPoma was reassessed using strict criteria. We evaluated the antisecretory efficacy (>50 % decrease of daily bowel movements), and antitumor efficacy (RECIST 1.1) of all treatments received.

RESULTS

Twenty-two patients were included. pNETs were mostly metastatic (77 %) and classified as grade 2 (83 %). Median follow-up was 78.2 months. Surgical excision of nonmetastatic VIPoma effectively controlled the secretory syndrome. Although 4/5 patients had metastatic recurrences, all patients were alive after median post-operative follow-up of 171 months. Among the 87 treatments received for metastatic VIPoma, curative-intent surgery (n = 14), somatostatin analogs alone (n = 11), chemotherapy (n = 23), transarterial liver embolization (TALE) (n = 14), everolimus (n = 10) and sunitinib (n = 7) achieved, respectively, 100 %, 67 %, 83 %, 50 %, 20 % and 100 % antisecretory efficacy. The 5-year OS rate was 63.6 %, with pejorative impact of higher Ki-67 index (P = 0.045) and higher plasma VIP concentration (P = 0.025).

CONCLUSIONS

Surgical resection of localized VIPoma is effective but rarely curative. For metastatic VIPoma, curative-intent surgery, chemotherapy and sunitinib are the therapeutic options that best combined antitumor and antisecretory efficacies.

Progress in the Management of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are a heterogeneous and orphan group of neoplasms that vary in their histology, clinical features, prognosis, and management. The treatment of PNETs is highly dependent on the stage at presentation, tumor grade and differentiation, presence of symptoms from hormonal overproduction or from local growth, tumor burden, and rate of progression. The US Food and Drug Administration has recently approved many novel treatments, which have altered decision making and positively impacted the care and prognosis of these patients. In this review, we focus on the significant progress made in the management of PNETs over the past decade, as well as the active areas of research. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Successful laparoscopic extirpation of a vasoactive intestinal polypeptide-secreting neuroblastoma originating from the right adrenal gland: A report of an infantile case

We herein report a 10-month-old female infant with a 4-month history of diarrhea with electrolyte abnormalities and growth impairment. A 4-cm right adrenal tumor was detected by computed tomography. No metastasis or accumulation on I¹²³ -metaiodobenzylguanidine scintigraphy was recognized in the tumor. A vasoactive intestinal peptide-secreting neuroblastic tumor was suspected, and octreotide was started, but the diarrhea persisted. Tumor extirpation was laparoscopically performed. After tumor removal, the symptoms improved immediately, and her growth caught up by 9 months after surgery. A minimally invasive approach for pediatric solid tumor is difficult, especially for neuroblastoma, but may be beneficial for the patient's recovery.

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.

Case Report: Irreversible Watery Diarrhea, Severe Metabolic Acidosis, Hypokalemia and Achloridria Syndrome Related to Vasoactive Intestinal Peptide Secreting Malignant Pheochromocytoma

BACKGROUND

Pheochromocytoma (PHEO) clinical manifestations generally mirror excessive catecholamines secretion; rarely the clinical picture may reflect secretion of other hormones. Watery diarrhea, hypokalemia and achlorhydria (WDHA) is a rare syndrome related to excessive secretion of vasoactive intestinal peptide (VIP).

CLINICAL CASE

A 73-year-old hypotensive man affected by adrenal PHEO presented with weight loss and watery diarrhea associated with hypokalemia, hyperchloremic metabolic acidosis (anion gap 15 mmol/l) and a negative urinary anion gap. Abdominal computed tomography scan showed a right adrenal PHEO, 8.1 cm in maximum diameter, with tracer uptake on ⁶⁸GaDOTA-octreotate positron emission tomography. Metastasis in lumbar region and lung were present. Both chromogranin A and VIP levels were high (more than10 times the normal value) with slightly elevated urine normetanephrine and metanephrine excretion. Right adrenalectomy was performed and a somatostatin analogue therapy with lanreotide started. Immunostaining showed chromogranin A and VIP co-expression, with weak somatostatin-receptor-2A positivity. In two months, patient clinical conditions deteriorated with severe WDHA and multiple liver and lung metastasis. Metabolic acidosis and hypokalemia worsened, leading to hemodynamic shock and exitus.

CONCLUSIONS

A rare case of WDHA syndrome caused by malignant VIP-secreting PHEO was diagnosed. High levels of circulating VIP were responsible of the rapidly evolving clinical picture with massive dehydration and weight loss along with severe hyperchloremic metabolic acidosis and hypokalemia due to the profuse untreatable diarrhea. The rescue treatment with lanreotide was unsuccessful because of the paucity of somatostatin-receptor-2A on VIP-secreting PHEO chromaffin cells.

Evolution of Neuroendocrine Tumor Therapy

To better understand developments in treatment of neuroendocrine tumors of the gastroenteropancreatic system, and the pivotal roles of native somatostatin and its long-acting analogues play in normal peptide regulation and neuropeptide excess associated with neuroendocrine tumors (NETs), this article delineates and defines distinct eras in the history and discovery of gastrointestinal endocrinology. We highlight the collaboration between academia and industry in basic science and the clinical research that advanced Lu-177-DOTATATE to approval as standard of care therapy for low-grade NETs. Examples of new radioisotopes and therapy compounds currently in development for diagnosis and therapy for high-grade NETs are also discussed.

Vasoactive Intestinal Peptide-Secreting Tumors: A Review

Vasoactive intestinal peptide-secreting tumors (VIPomas) are a group of rare neuroendocrine tumors, which cause a typical syndrome of watery diarrhea. Most of these tumors are found in the pancreas and are usually detected at a later stage. Although curative resection is not possible in most of these tumors, both symptom and tumor control can be achieved by a multidimensional approach, to enable a long survival of most patients. There are no clear-cut guidelines for the management of VIPomas because of the rarity of this neoplasm and lack of prospective data. In this review, we discuss the available evidence on the clinical features and management of these rare tumors.

Evaluation and Management of Neuroendocrine Tumors of the Pancreas

Pancreatic neuroendocrine tumors are a diverse group of neoplasms with a generally favorable prognosis. Although they exhibit indolent growth, metastases are seen in roughly 60% of patients. Pancreatic neuroendocrine tumors may produce a wide variety of hormones, which are associated with dramatic symptoms, but the majority are nonfunctional. The diagnosis and treatment of these tumors is a multidisciplinary effort, and management guidelines continue to evolve. This review provides a concise summary of the presentation, diagnosis, surgical management, and systemic treatment of pancreatic neuroendocrine tumors.

Imaging of Pancreatic-Neuroendocrine Tumours: An Outline of Conventional Radiological Techniques

IIntroduction:

Pancreatic Neuroendocrine Tumours (p-NETs) are an important disease entity and comprise of peptide-secreting tumours often with a functional syndrome.

:

Accounting for a small percentage of all pancreatic tumours, they have a good overall survival rate when diagnosed early, with surgery being curative. The role of nuclear medicine in the diagnosis and treatment of these tumours is evident. However, the vast majority of patients will require extensive imaging in the form of conventional radiological techniques. It is important for clinicians to have a fundamental understanding of the p-NET appearances to aid prompt identification and to help direct management through neoplastic staging.

Methods:

This article will review the advantages and disadvantages of conventional radiological techniques in the context of p-NETs and highlight features that these tumours exhibit.

Conclusion:

Pancreatic neuroendocrine tumours are a unique collection of neoplasms that have markedly disparate clinical features but similar imaging characteristics. Most p-NETs are small and welldefined with homogenous enhancement following contrast administration, although larger and less welldifferentiated tumours can demonstrate areas of necrosis and cystic architecture with heterogeneous enhancement characteristics.

:

Prognosis is generally favourable for these tumours with various treatment options available. However, conventional radiological techniques will remain the foundation for the initial diagnosis and staging of these tumours, and a grasp of these modalities is extremely important for physicians.

Pancreatic neuroendocrine microadenomatosis presenting as a functional VIPoma

Pancreatic microadenomas are benign tumors of neuroendocrine origin less than 5 mm in size. Whereas most microadenomas are non-functional; a few rare functional pancreatic microadenomas have been described in the setting of multiple endocrine neoplasia type one (MEN-1). In this report, we describe a unique case of multiple functional microadenomas of the pancreatic head in a patient who presented with persistent secretory diarrhea, refractory hypokalemia, metabolic acidosis and elevated plasma vasoactive intestinal peptide (VIP) levels. Following extensive serologic, radiographic and endoscopic work up, our patient underwent open pancreaticoduodenectomy with subsequent resolution of diarrheal symptoms and electrolyte abnormalities on postoperative follow up.

Chronic Diarrhea Secondary to Newly Diagnosed VIPoma

Vasoactive intestinal polypeptide-secreting tumors (VIPoma) are a rare pancreatic neuroendocrine tumor that can cause chronic diarrhea with 1 case per 10 million people per year. Diagnosis is made based on a combination of laboratory evaluation (serum VIP level), imaging findings (functional positron emission tomography-computed tomography [PET-CT]), and histological analysis (chromogranin A stain). We present a case of a male with 6 months of diarrhea and malaise who was found to have significant kidney injury and hypokalemia requiring admission to the medical intensive care unit. Subsequent laboratory evaluation while admitted eventually showed a low stool osmotic gap (–11 mOsm/kg) consistent with secretory diarrhea, in addition to significantly elevated VIP levels at 940 pg/mL (normal <75). Cross-sectional imaging with functional Gallium-68 dotatate PET-CT confirmed metastatic functional neuroendocrine tumor indicative of a VIPoma. Pathology on subsequent metastatic liver lesion aspiration was consistent with a well-differentiated VIPoma, and symptoms dramatically improved following initiation of octreotide therapy.

Symptomatic and Radiological Response to 177Lu-DOTATATE for the Treatment of Functioning Pancreatic Neuroendocrine Tumors

PURPOSE

Peptide receptor radionuclide therapy (PRRT) with the radiolabeled somatostatin analogue [Lutetium-177-DOTA0-Tyr3]octreotate (177Lu-DOTATATE) is widely applied for inoperable metastatic small intestinal and nonfunctioning pancreatic neuroendocrine tumors (pNETs). The aim of this study is to describe the safety and efficacy of the treatment of functioning pNETs.

METHODS

Patients were treated with up to four cycles of 177Lu-DOTATATE with an intended dose of 7.4 Gbq per cycle. Radiological (Response Evaluation Criteria in Solid Tumors 1.1), symptomatic, and biochemical response were analyzed retrospectively for all patients with a functioning pNET (insulinoma, gastrinoma, VIPoma, and glucagonoma) treated with 177Lu-DOTATATE. Quality of life (QOL) was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core Module questionnaire.

RESULTS

Thirty-four patients with a metastatic functioning pNET (European Neuroendocrine Tumor Society grade 1 or 2) were included: 14 insulinomas, 5 VIPomas, 7 gastrinomas, and 8 glucagonomas. Subacute hematological toxicity, grade 3 or 4 occurred in 4 patients (12%) and a hormonal crisis in 3 patients (9%). PRRT resulted in partial or complete response in 59% of patients and the disease control rate was 78% in patients with baseline progression. 71% of patients with uncontrolled symptoms had a reduction of symptoms and a more than 80% decrease of circulating hormone levels was measured during follow-up. After PRRT, median progression-free survival was 18.1 months (interquartile range: 3.3 to 35.7) with a concurrent increase in QOL.

CONCLUSION

Treatment with 177Lu-DOTATATE is a safe and effective therapy resulting in radiological, symptomatic and biochemical response in a high percentage of patients with metastatic functioning pNETs. Hormonal crises occur relatively frequent and preventive therapy should be considered before and/or during PRRT.

Paraneoplastic syndromes and other systemic disorders associated with neuroendocrine neoplasms

Neuroendocrine paraneoplastic syndromes (PNS) consist of metabolic disorders that accompany benign and malignant neoplasms but remain unrelated to mass effects or invasion by the primary tumor or its metastases. The underlying pathogenesis responsible for PNS usual clinical presentation relies on aberrant production of protein hormones, proteins and other substances by the tumor. Prompt recognition of characteristic signs and symptoms combined with serological identification of key substances may result in early diagnosis of PNS and its underlying malignancy. For these reasons, healthcare professionals should familiarize themselves with tumor-induced hypercalcemia, syndrome of inappropriate antidiuretic hormone, carcinoid syndrome, virilisation syndrome, gynecomastia, acromegaly, Cushing syndrome, osteogenic osteomalacia, tumor-induced hypoglycemia, necrolytic migratory erythema, and watery diarrhea, hypokalemia and achlorydria syndrome. Medical awareness for PNS can improve patient outcomes through earlier administration of cancer therapy and treatment, better symptomatic relief and prolong overall survival.

Intertumor heterogeneity in 60 pancreatic neuroendocrine tumors associated with multiple endocrine neoplasia type 1

BACKGROUND

Patients with multiple endocrine neoplasia type 1 (MEN-1) develop multiple pancreatic neuroendocrine neoplasias (PNENs). Size at diagnosis and growth during follow-up are crucial parameters. According to the WHO 2017, grading is another important parameter. The impact of grading compared to size (WHO 2000) on the clinical course needs to be evaluated.

METHODS

Sixty PNENs of six patients with MEN-1 were retrospectively evaluated.

RESULTS

Fifty-one tumors with a diameter of < 20 mm were graded as G1. Two of 9 tumors with diameters of ≥20 mm were graded as G2. Tumor size of ≥20 mm correlated significantly with higher proliferation (p = 0.000617). Lymph node metastases were documented in two patients with a total of 19 tumors. In one patient, all 13 tumors (diameter: 0.4 to 100 mm) were classified as G1. However, metastases were documented in 9/29 lymph nodes. In the other patient, 5 tumors (3.5 to 20 mm) were classified as G1. The sixth tumor (30 mm) was classified as G2 (Ki-67: 8%). Metastases were revealed in 2/20 lymph nodes.

CONCLUSIONS

Tumor size of ≥20 mm seems to correlate with more aggressive MEN-1 related pancreatic disease, regardless of individual proliferation. Tumors ≥20 mm and tumors graded as G2 should be treated surgically regardless of their size.

Neoplasms of the Neuroendocrine Pancreas: An Update in the Classification, Definition, and Molecular Genetic Advances

This review focuses on discussing the main modifications of the recently published 2017 WHO Classification of Neoplasms of the Neuroendocrine Pancreas (panNEN). Recent updates separate pancreatic neuroendocrine tumors into 2 broad categories: well-differentiated pancreatic neuroendocrine tumors (panNET) and poorly differentiated pancreatic neuroendocrine carcinoma (panNEC), and incorporates a new subcategory of "well-differentiated high-grade NET (G3)" to the well-differentiated NET category. This new classification algorithm aims to improve the prediction of clinical outcomes and survival and help clinicians select better therapeutic strategies for patient care and management. In addition, these neuroendocrine neoplasms are capable of producing large quantity of hormones leading to clinical hormone hypersecretion syndromes. These functioning tumors include, insulinomas, glucagonomas, somatostatinomas, gastrinomas, VIPomas, serotonin-producing tumors, and ACTH-producing tumors. Although most panNENs arise as sporadic diseases, a subset of these heterogeneous tumors present as parts on inherited genetic syndromes, such as multiple endocrine neoplasia type 1, von Hippel-Lindau, neurofibromatosis type 1, tuberous sclerosis, and glucagon cell hyperplasia and neoplasia syndromes. Characteristic clinical and morphologic findings for certain functioning and syndromic panNENs should alert both pathologists and clinicians as appropriate patient management and possible genetic counseling may be necessary.

Octreotide reverses shock due to vasoactive intestinal peptide-secreting adrenal pheochromocytoma: A case report and review of literature

Vasoactive intestinal peptide-producing tumors (VIPoma) usually originate in the pancreas and are characterized by diarrhea, hypokalemia, and achlorhydria (WDHA syndrome). In adults, nonpancreatic VIPoma is very rare. Herein, we report an unusual case of VIP-producing pheochromocytoma marked by persistent shock, flushing, and watery diarrhea and high sensitivity to octreotide. A 53-year-old woman was hospitalized for sudden-onset hypertension with convulsions, which then rapidly evolved to persistent shock, flushing, and watery diarrhea. Abdominal computed tomography indicated a left adrenal mass, accompanied by bleeding; and marked elevations of both plasma catecholamine and VIP concentrations were documented via laboratory testing. Surprisingly, all clinical symptoms responded swiftly to octreotide treatment. Once surgically treated, hormonal levels normalized in this patient, and the clinical symptoms dissipated. Postoperative pathological and immunohistopathological studies confirmed a VIP-secreting pheochromocytoma with strong, diffuse positivity for somatostatin receptor type 2. During a 6-mo follow-up period, she seemed in good health and was symptom-free.

Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are heterogeneous malignancies arising from the diffuse neuroendocrine system. They frequently originate in the gastroenteropancreatic (GEP) tract and the bronchopulmonary tree, and their incidence has steadily increased in the last 3 decades. Fundamental biologic and genomic differences underlie the clinical heterogeneity of NETs, and distinct molecular features characterize NETs of different grades and different primary sites. Although surgery remains the cornerstone of treatment for localized tumors, systemic treatment options for patients with metastatic NETs have expanded considerably. Somatostatin analogs have demonstrated both antisecretory and antitumor efficacy. Peptide receptor radionuclide therapy with lutetium-177 dotatate (¹⁷⁷ Lu-DOTATATE) has been approved for advanced GEP-NETs. The antitumor activity of everolimus has been demonstrated across a wide spectrum of NETs, and the antiangiogenic agent sunitinib has been approved for pancreatic NETs (pNETs). Chemotherapy with temozolomide and capecitabine has recently demonstrated an unprecedented prolongation of progression-free survival in a randomized trial of pNETs. Multiple retrospective series have reported the efficacy of liver-directed therapies both for palliating symptoms of hormone excess and for controlling tumor growth. Telotristat, an oral inhibitor of tryptophan hydroxylase, has been shown to reduce diarrhea in patients with carcinoid syndrome. Defining the therapeutic algorithm and identifying biomarkers predictive of response to treatments are among the main priorities for the next decade of research in the NET field.

The Genesis of the Neuroendocrine Tumors Concept: From Oberndorfer to 2018

The concept of neuroendocrine tumors (NETs) began in the 1900s with Oberndorfer's description of carcinoid tumors, followed by specific cytotoxic agents and the identification of somatostatin. NETs diagnosis was confirmed by World Health Organization classification. Histopathology included immunohistochemistry with specific antibodies. Imaging was refined with molecular imaging. Somatostatin is the leading agent for controlling clinical symptoms related to hormone production. Increasing interest in these tumors, previously thought rare, led to increased incidence and prevalence. Between 1960 and 1970, the true NET-concept was established with development of radioimmunoassays for peptides and hormones, and imaging with computerized tomography.

Uncommon reasons of the digestive tract-related paraneoplastic syndromes in children with neuroblastic tumors: three case reports

Aim of the study

presentation of the uncommon paraneoplastic syndromes related to the gastrointestinal tract that may occur in children with neuroblastic tumors and their impact on the disease course.

Material and methods

Retrospective analysis of three cases of patients mainly with digestive tract-related symptoms, who were originally admitted to the gastroenterology department from 2013 to 2016 and were finally diagnosed with neuroblastic tumors.

Results

The clinical data analysis showed that the symptoms from gastrointestinal tract were dominant in analyzed subjects. The first case is a girl with weight loss, bloating and severe diarrhea, admitted to the hospital in a state of dehydration. The laboratory tests revealed severe hypokalemia. Finally, vasoactive intestinal peptide (VIP) secreting ganglioneuroblastoma was diagnosed and effective surgery was performed. The second case was also a girl who suffered from the incidents of watery diarrhea and flatulence. The tumor was detected by computerized tomography scan. The 3^rd stage of ganglioneuroblastoma was diagnosed. The patient required chemotherapy, radiotherapy and surgery treatment. The third child was a boy, hospitalized due to abdominal pain, constipation and weakness. During the diagnostic process, the 4^th stage of neuroblastoma was recognized. The chemotherapy, surgery, radiotherapy and immunotherapy were applied.

Conclusions

In children with common abdominal symptoms as chronic flatulence, diarrhea or severe constipation of unknown etiology, the neuroblastic tumors should be considered.

Nothing But NET: A Review of Neuroendocrine Tumors and Carcinomas

This review covers the diverse topic of neuroendocrine neoplasms (NENs), a relatively rare and heterogeneous tumor type, comprising ~2% of all malignancies, with a prevalence of <200,000 in the United States, which makes it an orphan disease (Basu et al., 2010).1 For functional purposes, NENs are divided into two groups on the basis of clinical behavior, histology, and proliferation rate: well differentiated (low grade to intermediate grade) neuroendocrine tumors and poorly differentiated (high grade) neuroendocrine carcinoma (Bosman et al., 2010)2; this histological categorization/dichotomization is highly clinically relevant with respect to impact on treatment and prognosis even though it is not absolute since a subset of tumors with a low-grade appearance behaves similarly to high-grade lesions. Given the relative dearth of evidenced-based literature about this orphan disease as a whole (Modlin et al., 2008),3 since the focus of most articles is on particular anatomic subtypes of NENs (i.e., gastroenteropancreatic or pulmonary), the purpose of this review is to summarize the presentation, pathophysiology, staging, current standard of care treatments, and active areas of current research.

Paediatric VIPoma: A Jamboree of Electrolytes

Vasoactive intestinal peptide secreting tumour (VIPoma) is a rare type of neuroendocrine tumour (NET), primarily located in the tail of pancreas. This type of tumour presents with myriad of metabolic and electrolyte misbalances in the preoperative period, mainly due to increased vasoactive intestinal peptide (VIP) levels. Perioperative management of patients with VIPoma is challenging, especially when dealing with paediatric patients. The anaesthetic management of a two-year-old girl who was selected for VIPoma resection is hereby presented.

Ventricular fibrillation resulting from electrolyte imbalance reveals vipoma in MEN1 syndrome

Sporadic VIPoma is an exceedingly rare tumor with an annual incidence of 1:10 million people worldwide, yet it is described in approximately 5 % of MEN1 patients. The majority of VIPomas are malignant and radical surgery is the best therapeutic option. A 58-year-old man presented with cardiocirculatory arrest due to ventricular fibrillation. The patient had a 3-month history of epigastric pain with diarrhea. After reanimation, laboratory data revealed severe hypokalemia and hypercalcemia. Further investigations showed hyperparathyroidism, left adrenal adenoma and pituitary microprolactinoma and genetic diagnosis of MEN1 syndrome was made. Abdominal computed tomography revealed a 45 × 30 mm mass of the pancreatic head and two hepatic lesions, which proved to be neuroendocrine after 68 Ga PET and needle biopsy. Vasoactive intestinal peptide (VIP) serum level had increased. Subsequently the patient underwent pylorus-preserving pancreaticoduodenectomy and hepatic resection. Intraoperative VIP returned to normal values. Histopathology confirmed a pancreatic VIPoma metastatic to the liver. The postoperative course was unremarkable and the patient is well with no evidence of disease at a 48 months follow-up. Even in case of anusual presentation, when two or more main clinical findings of MEN1 related tumors are present, unrespectively to the presence of MEN1 mutation, MEN1 syndrome should be suspected. Surgery in MEN1 pancreatic neuroendocrine tumors is indicated both to treat symptoms and to avoid oncological progression even in advanced cases.

Unremitting watery diarrhoea in early childhood period

Chronic watery diarrhoea can be a presentation of gastrointestinal disease itself or a less-evident systemic disease. A 17-month-old boy presented with intractable diarrhoea, failure to gain weight, refractory tachycardia and severe hypertension. The ability to recognise and make a quick diagnosis of secretory type of diarrhoea dictated the outcome of patients with this ailment. Catecholamine hypersecretion was considered with the additional clues of refractory tachycardia and hypertension, a well-recognised phenomenon of neuroblastic tumours. A neuroblastic tumour can lead to vasoactive intestinal peptide (VIP) overexpression, which may result in secretory diarrhoea. In this situation, measurements of plasma VIP enabled crucial diagnosis. Imaging studies were used to identify and localise a neuroblastic tumour. Subsequent removal of the tumour was curative and led to the resolution of the symptoms.

Effect of hormone secretory syndromes on neuroendocrine tumor prognosis

The treatment of hormone hypersecretory syndromes caused by neuroendocrine tumors (NETs) can be a major challenge. NETs originating from the small intestine often secrete serotonin causing flushing, diarrhea and valve fibrosis, leading to dehydration or heart failure in severe cases. NETs from the pancreas can secrete a wider variety of hormones, like insulin, glucagon and gastrin leading to distinct clinical syndromes. Historically mortality in patients with functioning NETs was high due to the complications caused by the hypersecretion of hormones. This has been reduced with several drugs: proton-pump inhibitors decrease acid secretion caused by gastrinomas. Somatostatin analogs can inhibit the secretion of multiple hormones and these are now the cornerstone for treating patients with a gastroenteropancreatic NET. However, peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs and everolimus can also decrease symptoms of hypersecretion and increase progression-free survival. Several factors affect the survival in patients with a functioning NET. Complications of hypersecretion negatively impact survival; however, secretion of hormones is also often a sign of a well-differentiated NET and due to the symptoms, functioning NETs can be detected in an earlier stage suggesting a positive effect on prognosis. The effect on survival is also dependent on the type of hormone being secreted. This review aims to study the effect of hormone secretion on the prognosis of NETs with the contemporary treatments options available today.

Neuroendocrine tumors with syndromic vasoactive intestinal polypeptide hypersecretion: a retrospective study

Aim: Vasoactive intestinal polypeptide producing neuroendocrine tumors are rare and cause severe hormonal symptoms. Patients/methods: Eighteen patients with vasoactive intestinal polypeptide producing neuroendocrine tumors were analyzed with reviews of medical records, radiology and tumor tissue specimens. Results: Twelve patients (67%) had liver metastases at diagnosis. Chemotherapy, somatostatin analogs and interferon were given as medical therapies. Streptozocin/5-fluorouracil produced an objective response in 40% of the evaluable patients. Somatostatin analogs gave a clinical/biochemical response in eight out of nine patients. Transarterial embolization of the liver and peptide receptor radionuclide therapy was given to refractory cases. Sixteen patients died during the observation period. The median overall survival from diagnosis was 102 months. Conclusion: Systemic chemotherapy and somatostatin analogs should be given in cases of advanced disease or for hormonal symptoms.

Multimodal Treatment of Vasoactive Intestinal Polypeptide-producing Pancreatic Neuroendocrine Tumors with Liver Metastases

A 53-year-old man presented with diarrhoea and hypokalaemia and was diagnosed with a neuroendocrine tumour of unknown origin with multiple liver metastases. Somatostatin analogues led to a reduction in the size of the tumours and improvement of his symptoms. However, after several years, the tumours grew in size, and the patient's clinical symptoms recurred. The patient underwent transcatheter arterial embolization (TAE) of the hepatic artery to treat the liver metastases. Immediately after embolization, the symptoms disappeared. Although the patient had an unresectable vasoactive intestinal polypeptide-producing neuroendocrine tumour, the endocrine symptoms were able to be controlled with chemotherapy and TAE, resulting in a long-term survival.

Testing for Chronic Diarrhea

Chronic diarrhea is a frequently encountered symptom in clinical practice. The etiologies for chronic diarrhea are diverse and broad with varying clinical implications. A useful method of categorizing chronic diarrhea to guide a diagnostic work-up is a pathophysiology-based framework. Chronic diarrhea may be categorized as malabsorptive, secretory, osmotic, and inflammatory or motility related. Frequently, overlap between categories may exist for any given diarrhea etiology and diagnostic testing must occur with an understanding of the differential diagnosis. Investigations to achieve a diagnosis for chronic diarrhea range from screening blood and stool tests to more directed testing such as diagnostic imaging, and endoscopic and histological evaluation. The pathophysiology-based framework proposed in this chapter will allow the clinician to select screening tests followed by targeted tests to minimize cost and complications to the patient, while providing a highly effective method to achieve an accurate diagnosis.

Primary Pancreatic Secretinoma: Further Evidence Supporting Secretin as a Diarrheogenic Hormone

OBJECTIVES

To document the existence of primary pancreatic secretinoma in patients with watery diarrhea syndrome (WDS) and achlorhydria and establish secretin as a diarrheogenic hormone.

BACKGROUND

Vasoactive intestinal peptide (VIP) has been widely accepted as the main mediator of WDS. However, in 1968, Zollinger et al reported 2 female patients with pancreatic neuroendocrine tumors, WDS, and achlorhydria. During surgery on the first, a 24-year-old patient, they noticed distended duodenum filled with fluid and a dilated gallbladder containing dilute bile with high bicarbonate concentration. After excision of the tumor, WDS ceased and gastric acid secretion returned. The second, a 47-year-old, patient's metastatic tumor extract given intravenously in dogs, produced significantly increased pancreatic and biliary fluid rich in bicarbonate. They suggested a secretin-like hormone of islet cell origin explains WDS and achlorhydria. These observations, however, predated radioimmunoassay, immunohistochemical staining, and other molecular studies.

METHODS

The first patient's tumor tissue was investigated for secretin and VIP. Using both immunohistochemistry and laser microdissection and pressure catapulting technique for RNA isolation and subsequent reverse transcription polymerase chain reaction, the expression levels of secretin, and VIP were measured.

RESULTS

Immunoreactive secretin and its mRNA were predominantly found in the tumor tissue whereas VIP and its mRNA were scarce.

CONCLUSIONS

The findings strongly support that the WDS and achlorhydria in this patient may have been caused by secretin as originally proposed in 1968 and that secretin may act as a diarrheogenic hormone.

Emergency therapy for liver metastases from advanced VIPoma: surgery or transarterial chemoembolization?

VIPoma is a rare neuroendocrine tumor (NET) with a high potential to develop hepatic metastases and poor prognosis. The primitive tumor is nonsymptomatic and usually localized within the pancreas. Liver metastasis drives the prognosis and induces profuse watery diarrhea or renal failure. We herein present severe renal failure or diarrhea in two patients hospitalized in intensive care justifying emergency treatment of liver metastasis. The two patients experienced severe diarrhea due to a hypersecretion of vasoactive intestinal peptide (VIP) from liver metastasis released into the blood circulation. Therapeutic management was discussed and liver transarterial chemoembolization (TACE) was performed with chemotherapy-loaded embospheres, which cause necrosis of tumor lesions. TACE controlled the hormonal syndrome and made patients eligible for curative surgery. Tumor necrosis occurred and VIP levels collapsed. Surgery was performed in one of the two cases after TACE and the patient was considered in remission. Both patients were still alive after 3 years of follow up. Thus, TACE is feasible and appears to be an effective emergency treatment in patients with a VIP-hormonal syndrome due to liver metastases. Despite the biological disorder due to the hormonal secretion, an aggressive approach is warranted in VIP liver metastasis.

Surgical resection of vasoactive intestinal peptideoma with hepatic metastasis aids symptom palliation: A case report

Vasoactive intestinal peptideoma (VIPoma) is a rare pancreatic endocrine tumor associated with a well-defined clinical syndrome characterized by watery diarrhea, hypokalemia and metabolic acidosis. In adults, VIPoma is most commonly found in the pancreas, with 80% of the tumors occurring in the body and tail and 20% occurring in the pancreatic head. VIPomas can represent a significant diagnostic challenge due to their nonspecific clinical presentation, which can result in the misdiagnosis of a VIPoma as another condition, such as laxative overdose or a carcinoid secreting tumor. Surgical clearance of the tumor is the first-line treatment, even in cases with metastasis. The present study describes the case of a patient who presented with chronic watery diarrhea and hypokalemia due to a tumor in the pancreatic head, which was confirmed to contain immunoreactive vasoactive intestinal polypeptide via immunohistochemistry. A hepatic metastasis lesion was diagnosed following computed tomography. Stable control of symptoms was achieved after surgery and drug treatment. The study additionally reviews the clinical, histological, radiological and diagnostic features of the condition, as well as the therapeutic modalities that can be used to treat VIPoma in the pancreatic head with hepatic metastasis.

Streptozocin and 5-Fluorouracil for the Treatment of Pancreatic Neuroendocrine Tumors: Efficacy, Prognostic Factors and Toxicity

BACKGROUND

In our center, the combination of streptozocin (STZ) and 5-fluorouracil (5-FU) has been used as the first-line treatment in the majority of patients with pancreatic neuroendocrine tumors (pNETs) over the past few decades. The objective of the current study was to assess the efficacy, prognostic factors and safety of the combination of STZ and 5-FU.

PATIENTS AND METHODS

Medical records and radiological reports of 133 patients with pNETs who received the combination of STZ and 5-FU during the period 1981-2014 were retrospectively evaluated.

RESULTS

The median survival from the start of treatment was 51.9 months in the whole group. In the radiologically evaluable patients (n = 100), progression-free survival was 23 months. Complete response was reached in 3 patients (3%), partial response in 25 patients (25%), 64 patients (64%) had stable disease, and 8 patients (8%) had progressive disease. In a multivariate analysis, surgery of the primary tumor and having a G3 tumor were significant positive and negative prognostic factors of survival from the start of treatment, respectively. Having either a G3 tumor or a stage IV tumor were significant prognostic factors for a shorter progression-free survival. Chemotherapy had to be discontinued in 29 patients due to side effects, of which kidney toxicity (mainly grades 1-2) was the most frequent.

CONCLUSION

As shown in recent reports, the combination of STZ and 5-FU is effective in the treatment of pNETs in terms of survival and radiological response and has an acceptable toxicity profile.

A short history of neuroendocrine tumours and their peptide hormones

The discovery of neuroendocrine tumours of the gastrointestinal tract and pancreas started in 1870, when Rudolf Heidenhain discovered the neuroendocrine cells, which can lead to the development of these tumours. Siegfried Oberndorfer was the first to introduce the term carcinoid in 1907. The pancreatic islet cells were first described in 1869 by Paul Langerhans. In 1924, Seale Harris was the first to describe endogenous hyperinsulinism/insulinoma. In 1942 William Becker and colleagues were the first to describe the glucagonoma syndrome. The first description of gastrinoma by Robert Zollinger and Edwin Ellison dates from 1955. The first description of the VIPoma syndrome by John Verner and Ashton Morrison dates from 1958. In 1977, the groups of Lars-Inge Larsson and Jens Rehfeld, and of Om Ganda reported the first cases of somatostatinoma. But only in 2013, Jens Rehfeld and colleagues described the CCK-oma syndrome. The most recently updated WHO classification for gastrointestinal neuroendocrine tumours dates from 2010.

[Pancreatic neuroendocrine tumours. What do we know of their history?]

Starting with Paul Langerhans, who first described pancreatic islets in 1869, this article reviews the various protagonists who, in the last century and a half, have contributed to the discovery of the main hormones originating in the pancreas, the analytical methods for their measurement, the imaging techniques for identifying tumoural location, and the various pancreatic neoplasms.