Percutaneous Irreversible Electroporation for Pancreatic VIPoma: A Case Report.

The purpose of this study was to investigate the safety and efficacy of irreversible electroporation (IRE) for the management of unresectable pancreatic vasoactive intestinal peptide tumor (VIPoma) in a 34-year-old male patient. The initial symptom was watery diarrhea, which could not be stopped by fasting. Laboratory tests revealed high vasoactive intestinal peptide (VIP) hormone levels, hypokalemia, and metabolic acidosis. Computed tomography examination showed a 6.0 × 5.0-cm, contrast-enhanced lesion in the neck and body of the pancreas and obliteration of the portal vein. Pathological and immunohistochemical findings were indicative of pancreatic VIPoma. The patient was treated with octreotide and IRE, and had no obvious IRE-related complications, except for moderate pain at the puncture sites. The patient reported that the watery diarrhea had decreased gradually; moreover, the VIP hormone level was normalized 15 days after IRE. Computed tomography scans showed a large area of necrosis in the pancreatic lesion. The findings from this case indicated that IRE could be a feasible and safe technique in controlling pancreatic VIPoma; however, additional follow-up and findings from more cases are required to further confirm the efficacy of IRE ablation therapy for pancreatic VIPoma.

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.

Pancreatic Neuroendocrine Tumor Secreting Vasoactive Intestinal Peptide and Dopamine With Pulmonary Emboli: A Case Report.

CONTEXT: The vasoactive intestinal peptide-secreting neuroendocrine tumor (VIPoma) is a very rare pancreatic tumor. We report the first case of a patient with VIPoma that co-secreted dopamine and had pulmonary emboli. CASE DESCRIPTION: A 67-year-old woman presented with 2 months of watery diarrhea, severe generalized weakness,6.8 kg of weight loss, a facial rash, and hypokalemia. Colonoscopy did not reveal the cause of the chronic diarrhea. Initial biochemical testing showed markedly elevated serum vasoactive intestinal peptide (VIP) and pancreatic polypeptide. Computed tomography scan of the abdomen and pelvis revealed a 5.4-cm distal pancreatic mass. Octreoscan showed an intense uptake in the area of the pancreatic mass. Incidental pulmonary emboli were found and treated. Additional biochemical testing revealed a markedly elevated urinary dopamine level. The patient received preoperative α-blockade and octreotide. She underwent a successful laparoscopic distal pancreatectomy. Postoperative urinary dopamine and pancreatic polypeptide were within normal limits. Serum VIP decreased by half but remained elevated. Pathology confirmed a grade 1 pancreatic neuroendocrine tumor without lymph node metastasis. The patient's symptoms resolved and no longer required octreotide. Metastatic workup including computed tomography, F18-fluorodeoxglucose positron emission tomography, and Ga68-DOTATATE scans were negative during 4 years of follow-up. CONCLUSIONS: VIPoma is a rare subtype of pancreatic neuroendocrine tumor that can secrete dopamine and can be associated with thromboembolism.

A tale of two tumors: treating pancreatic and extrapancreatic neuroendocrine tumors.

Despite their perceived rarity, gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rising in incidence and prevalence. The biology, natural history, and therapeutic options for GEP-NETs are heterogeneous: NETs arising in the pancreas can be distinguished from those arising elsewhere in the gastrointestinal tract, and therapy is dichotomized between these two groups. Somatostatin analogues are the mainstay of oncologic management of bowel NETs; everolimus, streptozocin, and sunitinib are approved to treat pancreatic NETs. There are significant differences in molecular genetics between pancreatic and extrapancreatic NETs, and studies are evaluating whether additional NET patients may benefit from targeted agents. We discuss the distinguishing features of these two groups of tumors, as well as the therapeutic implications of the distinction. We also examine the evolving therapeutic landscape and discuss the likelihood that treatment will be developed independently for pancreatic and extrapancreatic gastrointestinal NETs, with novel therapeutics effective for newly identified pathologically or molecularly defined subgroups.

Diarrhea caused by circulating agents.

Circulating agents cause intestinal secretion or changes in motility with decreased intestinal transit time, resulting in secretory-type diarrhea. Secretory diarrhea as opposed to osmotic diarrhea is characterized by large-volume, watery stools, often more than 1 L per day; by persistence of diarrhea when patients fast; and by the fact that on analysis of stool-water, measured osmolarity is identical to that calculated from the electrolytes present. Although sodium plays the main role in water and electrolyte absorption, chloride is the major ion involved in secretion.

Inflammatory breast cancer with refractory diarrhea: a case report.

Excessive amounts of vasoactive intestinal polypeptide (VIP) cause a special clinical syndrome characterized by secretory diarrhea, hypokalemia and dehydration. A careful clinical workup of a 62-year-old female admitted for refractory diarrhea revealed a neglected inflammatory right breast ductal carcinoma with VIP hypersecretion without any localized abdominal tumor. Immunohistochemistry of the breast biopsy showed neuroendocrine characteristics with positive staining for VIP, and Octreotide scan showed hyperfixation to the right breast and axilla. Primary therapy of breast cancer with hormones and chemotherapy achieved transitory regression of diarrhea, VIP level decrease, and tumor border reduction. Bilateral modified radical mastectomy and irradiation of the tumor failed to prevent liver and bone dissemination of the disease. Once more, partial response was obtained by octreotide and salvage chemotherapy; however, the patient died from progressive disease 23 months after initial diagnosis. To our best knowledge, this unusual presentation of a breast carcinoma with related VIPoma syndrome is the first reported case in the literature.

Vasoactive intestinal polypeptide secreting pancreatic tumour with hepatic metastases: long term survival after orthotopic liver transplantation.

BACKGROUND: VIPomas are rare neuroendocrine tumours, with metastases often confined to the liver. Orthotopic liver transplantation may be considered in patients with metastases confined to the liver, however the long term benefits have yet to be shown. AIMS: To discuss the role of orthotopic liver transplantation for neuroendocrine tumours including VIPomas. METHODS: We describe the case of a very rare pancreatic VIPoma, the therapeutic modalities employed, including orthotopic liver transplantation, and present the results of a relevant literature search. RESULTS: This case is the longest (25 years) reported in the literature for survival from a VIPoma after initial diagnosis and long term survival after liver transplantation (9 years). CONCLUSION: Liver transplantation for metastatic VIPomas confined to the liver may be justified in selected patients to provide symptomatic hormonal control and pain from tumour bulk, provided there is no extra hepatic disease and medical treatment has been exhausted.

Neuroendocrine tumors of the pancreas.

The neuroendocrine tumors (NET) of the pancreas are very rare lesions with frequency of about 3 to 10 per 1 000 000 inhabitants. The neuroendocrine tumors composes a heterogeneous group of tumors. The gastro-entero-pancreatic tumors (GEP) constitute 70% of all NET and 2% of all digestive system tumors. There have been several attempts to classify those lesions and since 2000 exists WHO classification which divides NET according to malignancy and histologic structure. The most often NET of the pancreas are insulinoma, gastrinoma, glucagonoma, somatostatinoma, VIPoma. There is a recommendation to assay hormonal activity, measure concentration of specific peptides, biogenic amines and hormones produced by NET cells to establish diagnosis. Those tests are useful in monitoring treatment and in prognostication course of the disease. Imaging methods especially useful in localization GEP-NET are: ultrasound (US), endoscopic ultrasound (EUS), somatostatin receptor scintigraphy (SRS), computer tomography (CT), magnetic resonance (MR) and angiography. The most sensitive method in preoperative diagnosis seems to be EUS or less accessible intra ductal ultrasonography (IDUS). Surgical treatment depends on progression of disease as well as on localization of tumor and consists in both radical methods and palliative operations. The gold standard in pharmacological treatment are somatostatin analogs which can induce long-term remission even in inoperable lesions. Although NET of pancreas are very rare. they are still important diagnostic and therapeutic problem and requires interdisciplinary co-operation. The neuroendocrine tumors should be treated in centers with highest rank of references.

BRAF gene mutations are rare events in gastroenteropancreatic neuroendocrine tumors.

The BRAF gene, one of the human isoforms of RAF, is activated by ras, leading to cooperative effects in cells responsive to growth factor signals. We studied the frequency of BRAF and k-ras-2 mutations in primary neuroendocrine gastroenteropancreatic (GEP) tumors. Mutation analysis of the BRAF and k-ras-2 genes was performed in 40 primary neuroendocrine tumors of the GEP system. The expression of extracellular signaling-related kinase (ERK) 1/2, an important downstream point of convergence in the ras-RAF-mitogen-activated protein-ERK pathway was analyzed immunohistochemically. We detected one 1796 T-->A BRAF mutation that led to a substitution of valine by glutamic acid at position 599 (V599E) in 40 primary neuroendocrine GEP tumors (3%). We failed to detect specific mutation of the k-ras-2 gene. We identified constitutively activated ERK in almost all neuroendocrine tumor tissues tested irrespective of BRAF mutation or localization or functional activity. These results suggest that BRAF mutations do not have a role in tumorigenesis of neuroendocrine tumors. Nevertheless, activation of the RAF/mitogen-activated protein kinase pathway might have a causative role in the development of neuroendocrine tumors, independent of BRAF or k-ras-2 mutation.

[The VIP-secreting tumor as a differential diagnosis of protracted diarrhea in pediatrics]. / Der VIP-produzierende Tumor in der Pädiatrie als Differenzialdiagnose der protrahierten Diarrhö

BACKGROUND: Vasoactive intestinal peptide (VIP) can be produced by mature neurogenic tumors. Pathologically elevated VIP plasma levels cause secretory diarrhea with excessive loss of water and electrolytes. Despite the clinical severity diagnosis of a VIP-secreting tumor is often delayed and subsequently its extirpation as the mainstay of therapy. PATIENTS: We report on two patients with ganglioneuroblastoma and secretory diarrhea. We contrast the case of a 13-month-old boy with advanced symptoms of secretory diarrhea, high VIP plasma levels, and late diagnosis to the case of a 14-month-old boy with mild secretory diarrhea and normal VIP plasma levels but positive proof of VIP in tumor tissue. Reviewing the literature we found 57 cases of pediatric VIP-secreting tumors. RESULTS: The clinical situation is characterized by the typical symptoms of secretory diarrhea with hypokalemia and metabolic acidosis. Histopathology predominantly reveals ganglioneuroblastoma or ganglioneuroma. The symptoms mostly stop after complete resection of the tumor whereas lack of resection is associated with elevated mortality rates. CONCLUSIONS: In case of prolonged therapy-resistant secretory diarrhea the existence of a VIP-secreting tumor should be considered. Diagnostic work-up should include the assessment of VIP plasma levels, catecholamines in urine, and appropriate imaging techniques in order to rule out or confirm the possibility of a VIP producing tumor.

Diagnosis and treatment of VIPoma in China: (case report and 31 cases review) diagnosis and treatment of VIPoma.

OBJECTIVES: To discuss the experience of diagnosis and treatment of VIPoma by summarizing clinical information of 31 patients with VIPoma in China. METHODS: To analyze clinical manifestations, laboratory examinations, imaging features, operation, pathologic findings, and follow-up survey of 31 patients, among them 1 case was from our hospital and the other 30 cases were reported in Chinese literature from 1977 to 2002. RESULTS: Periodical backache, skin rash, and polyps of colon were never reported previously, all of which except polyps disappeared after operation. Partial resection of superior mesenteric vein was also never reported. The mean serum value of VIP which had been very high before operation, decreased markedly after the operation (963.2 pg/ml Versus 131.9 pg/ml),the immunohistochemical expression of many kinds of digestive hormone including VIP presented positive. Hepatic involvement was 29.0%,nodal metastasis was 9.7%. CONCLUSIONS: VIPoma is rare. Typical symptoms and the serum value of VIP are keys to diagnosis before operation, Surgical resection is the most effective means for cure. surgical debulking of the tumor, somatostatin analogues can be used for good palliation.

Coproantibodies to the enteropathogenic Escherichia coli vaccine candidates BfpA and EspB in breastfed and artificially fed children.

A diagnostic test was developed to discriminate active from past enteropathogenic Escherichia coli (EPEC) infection, which uses the affinity-purified recombinant proteins BfpA (bundle-forming pilus (BFP) structural repeating subunit A) and EspB (pore-forming secreted protein B) as reliable markers of virulence to detect antigen-specific coproantibodies by immunoblot analysis, and verification of active typical EPEC infection by gene-specific (bfpA and espB) PCR amplification using DNA extracted directly from specimens and/or culture-enriched preparations. To begin addressing the potential protective role of anti-EPEC antibodies at early age, the prevalence of IgA coproantibodies to these antigens was determined in either breastfed or artificially fed children <2 years of age hospitalized for watery diarrhea.

[Sonographic detection of a "VIPoma" in a small child with intractable gastroenteritis]. / Sonographische Detektion eines "VIPoms" bei einem Kleinkind mit therapieresistenter Gastroenteritis.

As case report we describe a rare cause of intractable "gastroenteritis" detected by ultrasonography. The 14 months-old boy was admitted to hospital because of intensive dehydration due to massive vomiting and diarrhoea. A salmonella enteritis with intractable hyponatraemia and hypokalaemia was thought to be the cause. After a dramatic relapse during oral treatment measures, further extensive laboratory tests finally disclosed an elevated serum level of vasoactive intestinal polypeptide ("VIP"). The VIP secreting tumor ("VIPoma") was detected ultrasonographically in a retroperitoneal localization mediocaudally of the right kidney. Diffuse distinct calcifications and an increased perfusion could be demonstrated. Intraspinal tumour spread was excluded by magnetic resonance imaging. After complete surgical removal of the tumour the clinical symptomatology normalized promptly and permanently. A VIP-excreting ganglioneuroblastoma with low grade growth fraction ("VIPoma") was diagnosed histologically. Common gastroenteritis in childhood represents no indication for ultrasound. In cases of unclear and therapy-resistant symptomatology, however, diagnostic work-up should include ultrasonography to search for retroperitoneal or pancreatic VIP-excreting tumours.

Expression of somatostatin receptor and effects of somatostatin analog on pancreatic endocrine tumors.

PURPOSE: Somatostatin analogs have been administered to patients with pancreatic endocrine tumors in an attempt to inhibit hormone hypersecretion and prevent tumor growth. It is speculated that their efficacy is correlated with the expression of specific subtypes of somatostatin receptors. The aim of this study was to immunohistochemically evaluate the expression of somatostatin receptor subtypes in human pancreatic endocrine tumors, and to determine whether the expression of these subtypes is correlated with the effectiveness of the somatostatin analogs. METHODS: Somatostatin receptor subtypes 1, 2, and 3 (sst 1, 2, and 3) were immunohistochemically investigated in seven pancreatic endocrine tumors: four insulinomas, one VIPoma, and two nonfunctioning tumors associated with multiple endocrine neoplasia type I, using paraffin sections. Three of the four patients with insulinoma were given an octreotide injection. RESULTS: Cells were homogeneously stained in the tumor region. More than 85% of the specimens expressed sst 1, 2, and 3. There was no difference among the immunohistochemical stainings of somatostatin receptor subtypes according to most tumor characteristics; however, the expression of sst 2 was extremely positive, and the expression of sst 3 was moderately positive in the specimen from a patient in whom the octreotide injection had proven very effective. CONCLUSION: These findings indicate that the efficacy of octreotide may be correlated with the density of sst 2 and 3 in an immunohistological study using paraffin sections.

Surgical treatment of pancreatic vasoactive intestinal polypeptide-secreting tumor: a case report.

A 68-year-old woman presented with secretory watery diarrhea causing hypokalimia, hypoalbuminemia and dehydration for 5 years. Subsequent investigations including abdominal ultrasonography and computed tomography scanning revealed a mass measuring 7 x 6 cm in the pancreatic tail. The diagnosis of pancreatic VIPomas was suspected on the basis of clinical symptoms. The patient underwent distal pancreatectomy and splenectomy after resuscitation of electrolyte imbalance, dehydration and malnutrition. The pathological examination with histoimmunochemical stain confirmed the diagnosis. Postoperative course is uneventful and the patient does not have symptoms any longer during the follow-up period.