Tumors of the endocrine pancreas

Localization Defines Streptozotocin/5-FU Response in Primary Pancreatic Neuroendocrine Tumours

INTRODUCTION

Incidence of pancreatic neuroendocrine tumours (pNETs) is on the rise. The only curative treatment is surgical resection in localized or oligo-metastatic disease. However, patients may present with locally advanced or unresectable primary tumours. So far, no conversion therapy to achieve resectability has been established, which is partly due to lack of data on primary tumour response to therapies. Here, we specifically evaluate the primary tumour response to streptozocin/5-FU in a large cohort of metastatic pNET patients.

METHODS

Five ENETS centres in Germany contributed 84 patients to the study cohort for retrospective analysis.

RESULTS

Overall response rate (ORR) in primary tumours was 34% and disease control rate (DCR) 88%. ORR was different in metastases at 44% and DCR at 70%. Partial remission in primary tumours was more frequent among those located in pancreatic tail than that in pancreatic head (49% vs. 14%, p = 0.03). Correspondingly, metastases from tumours originating from pancreatic tail responded more frequently than metastases originating from pancreatic head (88.5% vs. 41.7%, p = 0.005). The median PFS of the primary tumours was longer than that in metastases (31 months vs. 16 months; p = 0.04). Considerable downsizing of the primary tumour was rare and occurred primarily in tumours located in the pancreatic tail.

CONCLUSION

STZ/5-FU can achieve disease stabilization in a high proportion of metastatic pNET patients. In the majority of cases however it does not induce substantial downsizing of the primary tumour, thus possibly limiting its potential as conversion chemotherapy. Furthermore, the difference in response rate observed between different primary tumour locations warrants further exploration.

Vague neuroglycopenic complaints camouflage diagnosis of adolescent insulinoma: a case report

Background

Insulinoma is a rare diagnosis in the general population with estimates of 1 in 250,000 people per year. Reports of these pancreatic islet cell tumors are even more unusual in children and adolescents. Chronic hypoglycemia due to an insulinoma often presents with neuroglycopenic symptoms that can easily be overlooked, especially in adolescents where nonspecific complaints are common. This may result in delayed diagnosis with prolonged periods of untreated hypoglycemia and associated complications. The rarity of pediatric insulinoma, vagueness of presenting symptoms, and challenge of tumor localization make insulinoma a true diagnostic quandary for clinicians.

Case Presentation

In this report, we present a 15-year-old female who visited her primary care provider complaining of intermittent episodes of altered mental status including fatigue, irritability, and poor concentration. Her outpatient management included routine laboratory studies, drug screening, electroencephalogram (EEG), valproic acid initiation, CT scan of the abdomen, and endoscopic ultrasound with documentation of hypoglycemia, but otherwise inconclusive results. The patient was admitted to a tertiary children’s hospital with severe refractory hypoglycemia 8 months after the initial evaluation. A serum critical sample was obtained and magnetic resonance imaging (MRI) of the abdomen performed which confirmed the presence of a pancreatic mass ultimately identified as an insulinoma. She went on to have surgical resection of her tumor resulting in complete resolution of her hypoglycemia and associated symptoms.

Conclusion

Within this report we demonstrate the importance of being vigilant for fasting hypoglycemia secondary to insulinoma even when the patient presents with nonspecific symptoms such as fatigue, irritability, or problems with concentration. If these neuroglycopenic complaints are unnoticed or misdiagnosed, patients with a potentially curable disease are put at risk of neurologic injury, or even death, due to untreated severe hypoglycemia.

Surgical Management of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are uncommon tumors with a range of clinical behavior. Some PNETs are associated with symptoms of hormone secretion, with increased systemic levels of insulin, gastrin, glucagon, or other hormones. More commonly, PNETs are nonfunctional, without hormone secretion. Surgical resection is the mainstay of therapy, particularly for localized disease. Surgical therapy must be tailored to tumor and clinical characteristics. Resection may be particularly indicated in the setting of hormone hypersecretion. Small, incidental PNETs are increasingly managed nonoperatively. Surgery may also be indicated in some instances of metastatic disease, if all metastatic foci may be removed.

Surgical treatment and clinical outcome of nonfunctional pancreatic neuroendocrine tumors: a 14-year experience from one single center

Our primary aim of the present study was to analyze the clinical characteristics and surgical outcome of nonfunctional pancreatic neuroendocrine tumors (non-F-P-NETs), with an emphasis on evaluating the prognostic value of the newly updated 2010 grading classification of the World Health Organization (WHO).Data of 55 consecutive patients who were surgically treated and pathologically diagnosed as non-F-P-NETs in our single institution from January 2000 to December 2013 were retrospectively collected.This entirety comprised of 55 patients (31 males and 24 females), with a mean age of 51.24 ± 12.95 years. Manifestations of non-F-P-NETs were nonspecific. Distal pancreatectomy, pancreaticoduodenectomy, and local resection of pancreatic tumor were the most frequent surgical procedures, while pancreatic fistula was the most common but acceptable complication (30.3%). The overall 5-year survival rate of this entire cohort was 41.0%, with a median survival time of 60.4 months. Patients who underwent R0 resections obtained a better survival than those who did not (P < 0.005). As for the prognostic analysis, tumor size and lymph invasion were only statistically significant in univariate analysis (P = 0.046 and P < 0.05, respectively), whereas the newly updated 2010 grading classification of WHO (G1 and G2 vs G3), distant metastasis, and surgical margin were all meaningful in both univariate and multivariate analysis (P = 0.045, 0.001, and 0.042, respectively).Non-F-P-NETs are a kind of rare neoplasm, with mostly indolent malignancy. Patients with non-F-P-NETs could benefit from the radical resections. The new WHO criteria, distant metastasis and surgical margin, might be independent predictors for the prognosis of non-F-P-NETs.

Preoperative tumor studies using MRI or CT in patients with clinically suspected insulinoma

PURPOSE

Insulinomas are rare tumors that originate from the islet cells of the pancreas. The aims of this study were to localize insulinomas preoperatively using CT and/or MRI in correlation with postoperative pathological results.

PATIENTS AND METHODS

Between December 2001 and June 2010, 27 consecutive patients with clinically suspected insulinoma were surgically treated in our university hospital. Preoperative CT (14 of 27 patients) and MRI studies (14 of 27 patients, one patient had both MRI and CT), operation reports, intraoperative ultrasonography reports, and pathological diagnoses were analyzed retrospectively. For each lesion, images were analyzed based on the presence of enhancement or the characteristics of signal intensities. Pathologic correlation was available for all the lesions.

RESULTS

The female: male ratio was 2.9, with a mean age of 47.5 years (range 12-82) . Preoperative tumor localization was achieved by means of MRI and CT. A focal pancreatic lesion, which was hypointense on T(1)-weighted sequences, was detected on all the MR images (14 of 27 patients; 100%). These lesions were isointense (4 cases) to slightly hyperintense (10 of 14 cases) on T(2)-weighted sequences. In T(1)-weighted fat-suppressed contrast-enhanced sequences, there were two types of enhancement: homogeneously hyperintense lesions (in 10 of 14 cases) or peripherally hyper-, centrally isointense (in 4 of 14 cases). On all the CT images (14 of 27 patients), there was no detectable lesion on precontrast series; on arterial series in 13 of 14 patients (arterial series has not been done in one patient), lesions enhanced hypervascular in contrast to the rest of the pancreas with a mean enhancement of 147 HU (range 113-248) and 95 HU (range 65-141), respectively. On venous series in 13 of 14 patients (venous series has not been done in one patient), there was an enhanced lesion in contrast to the rest of the pancreas with a mean enhancement of 110 HU (range 91-151) and 86 HU (range 65-137), respectively. Intraoperative ultrasonography was performed in 11 of 27 patients to localize the tumor, which correlated with the results of the mentioned preoperative studies. Tumor size ranged from 9 × 11 to 31 × 37 mm. Enucleation was carried out in 14 patients, Whipple in 5, segmental resection in 3 and left distal pancreatectomy in 5 patients. The mortality rate was 0. Pathological findings were insulinoma or neuroendocrine tumors in 26 of 27 cases. One patient had a pathological finding of chronic pancreatic disease with intraepithelial neoplasia (grade 1A).

CONCLUSION

We conclude that the preoperative localization of insulinoma in clinically suspected patients can be made on the basis of MRI and/or CT studies. A hallmark lesion is hypointense in T(1)-weighted sequences, homogeneously or peripherally hyperintense in T(1)-weighted fat-suppressed contrast-enhanced sequence using MRI (100% of cases) or/and a hypervascular enhanced lesion on arterial (100% of CT studies) and on venous series using CT (66.7% of CT studies).

Imaging of neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a large group of diverse neoplasms with a wide spectrum of clinical, imaging, and pathologic findings. Imaging diagnosis of NETs can be challenging, and several complementary imaging modalities may be needed during the diagnostic workup. Accurate interpretation of the imaging findings is important to facilitate diagnosis and contribute to patient management. This article discusses the gastrointestinal site-specific features and the tumor-specific features of several NETs and the role of several imaging modalities such as computed tomography, MR imaging, ultrasonography, and positron emission tomography in the evaluation of these NETs.

Multimodality treatment of unresectable hepatic metastases from pancreatic glucagonoma

Glucagonomas are pancreatic islet cell tumors arising from the alpha cells which belong to neuroendocrine tumors. They frequently metastasize to the liver. We report the case of a 52- year old man with a pancreatic glucagonoma with synchronous multiple liver metastases treated by surgery, transarterial chemoembolization, percutaneous radiofrequency thermal ablation and long-acting octreotide. Our report confirms that a multimodal approach is very effective in patients with unresectable liver metastases from pancreatic endocrine tumors providing long-lasting palliation and probably prolonging survival.

Serum gastrin in Zollinger-Ellison syndrome: I. Prospective study of fasting serum gastrin in 309 patients from the National Institutes of Health and comparison with 2229 cases from the literature

The assessment of fasting serum gastrin (FSG) is essential for the diagnosis and management of patients with the Zollinger-Ellison syndrome (ZES). Although many studies have analyzed FSG levels in patients with gastrinoma, limited information has resulted from these studies because of their small size, different methodologies, and lack of correlations of FSG levels with clinical, laboratory, or tumor features in ZES patients. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of 309 patients with ZES and compare our results with those of 2229 ZES patients in 513 small series and case reports in the literature. In the NIH and literature ZES patients, normal FSG values were uncommon (0.3%-3%), as were very high FSG levels >100-fold normal (4.9%-9%). Two-thirds of gastrinoma patients had FSG values <10-fold normal that overlap with gastrin levels seen in more common conditions, like Helicobacter pylori infection or antral G-cell hyperplasia/hyperfunction. In these patients, FSG levels are not diagnostic of ZES, and gastrin provocative tests are needed to establish the diagnosis. Most clinical variables (multiple endocrine neoplasia type 1 status, presence or absence of the most common symptoms, prior medical treatment) are not correlated with FSG levels, while a good correlation of FSG values was found with other clinical features (prior gastric surgery, diarrhea, duration from onset to diagnosis). Increasing basal acid output, but not maximal acid output correlated closely with increasing FSG. Numerous tumoral features correlated with the magnitude of FSG in our study, including tumor location (pancreatic > duodenal), primary size (larger > smaller) and extent (liver metastases > local disease). In conclusion, this detailed analysis of FSG in a large number of patients with ZES allowed us to identify important clinical guidelines that should contribute to improved diagnosis and management of patients with ZES.

Small cell carcinoma of the pancreas in association with a choledochal cyst: immunohistochemical characterization and complete response to combination chemotherapy

Carcinomas arising in choledochal cysts are well recognized; however, small cell carcinomas have not been reported to arise in choledochal cysts. Extrapulmonary small cell carcinomas have been recognized as unique clinicopathologic entities for decades, and have been found arising in numerous sites. Recently there have been several reviews of the subject (Remick et al.: Medicine 66:457-71, 1987; Richardson and Weiland: Seminars in Oncology 9:484-496, 1982; Levenson et al.: Journal of the National Cancer Institute 67:607-612, 1981). Small cell carcinoma of the pancreas has only rarely been described (Reyes and Wang: Cancer 47:2500-2502, 1981; Corrin et al.: Cancer 31:1523-1527, 1973). These tumors must be distinguished from carcinoid tumors and islet cell tumors, which can often lead to histochemical and histologic confusion (Richardson and Weiland: Seminars in Oncology 9:484-496, 1982). Their response to therapy has not been well documented. We report here a small cell carcinoma of the pancreas that arose within a choledochal cyst and that had immunohistochemical characteristics supporting a neuroendocrine origin but that lacked evidence of islet cell differentiation. A complete response to chemotherapy is also described.

Glucose-regulated Glucagon Secretion Requires Insulin Receptor Expression in Pancreatic α-Cells

The insulin receptor (IR) and its signaling appear to be essential for insulin secretion from pancreatic beta-cells. However, much less is known about the role of the IR in alpha-cells. To assess the role of the IR in glucagon and insulin secretion, we engineered adeno-viruses for high efficiency small interference RNA (siRNA)-IR expression in isolated mouse pancreatic islets and lentiviruses for siRNA-IR expression in pancreatic alpha- and beta-cell lines (alpha-TC6 and MIN6) with specific, long term stable IR knockdown. Western blot analysis showed that these strategies resulted in 60-80% reduction of IR protein in islets and alpha- and beta-cell lines. Cell growth was reduced by 35-50% in alpha-TC and MIN6 cells stably expressing siRNA-IR, respectively. Importantly, glucagon secretion, in response to glucose (25 to 2.8 mm), was completely abolished in islets expressing siRNA-IR, whereas secretion increased 1.7-fold in islets expressing control siRNA. In contrast, there was no difference in glucose-stimulated insulin secretion when comparing siRNA-IR and siRNA control, with both groups showing a 1.7-fold increase. Islet glucagon and insulin content were also unaffected by IR knockdown. To further explore the role of the IR, siRNA-IR was stably expressed in pancreatic cell lines, which dramatically suppressed glucose-regulated glucagon secretion in alpha-TC6 cells (3.4-fold) but did not affect GSIS in MIN6 cells. Defects in siRNA-IR-expressing alpha-cells were associated with an alteration in the activity of Akt and p70S6K where insulin-induced phosphorylation of protein kinase B/AKt was greatly reduced while p70S6K activation was enhanced, suggesting that the related pathways play important roles in alpha cell function. This study provides direct evidence that appropriate expression of the IR in alpha-cells is required for glucose-dependent glucagon secretion.

Surgical treatment of non-functioning pancreatic islet cell tumors

Pancreatic endocrine tumors (PETs) are rare neoplasms originating from the amine precursor uptake and decarboxylation (APUD) stem cells. Although the majority of PETs are sporadic, they frequently occur in familial syndromes. PETs may cause a variety of functional syndromes or symptoms of local progression if they are non-functional. General neuroendocrine tumor markers are highly sensitive in the diagnostic assessment of a PET. Imaging studies for tumor localization and staging include computer tomography (CT) scan, magnetic resonance imaging (MRI), In(111)-octreotide scan, MIBG, and endoscopic ultrasonography (EUS). Treatment of PETs often requires a multi-modality approach; however, surgical resection remains the only curative therapy for localized (non-metastatic) disease. Treatment of metastatic disease includes biologic agents, cytotoxic chemotherapy, and liver-directed therapies.

Fluorouracil, doxorubicin, and streptozocin in the treatment of patients with locally advanced and metastatic pancreatic endocrine carcinomas

PURPOSE

The role of systemic chemotherapy in the management of pancreatic endocrine carcinoma (islet cell carcinoma; PEC) is an area of considerable controversy. Response rates ranging from 6% to 69% have been reported for streptozocin-based chemotherapy. We retrospectively studied 84 patients with locally advanced or metastatic PEC who had been treated with fluorouracil, doxorubicin, and streptozocin (FAS) to determine the objective response rate, duration of progression-free survival (PFS), and duration of overall survival (OS).

PATIENTS AND METHODS

Eligible patients had histologic or cytologic confirmation of their tumor and measurable disease on computed tomography or magnetic resonance imaging scans. Response to treatment was evaluated in this study using the new international criteria proposed by the Response Evaluation Criteria in Solid Tumors Committee.

RESULTS

Sixty-one of the patients were male and 23 were female, with a median age of 54 years (range, 24 to 78 years). The response rate (RR) to FAS was 39%, with a median response duration of 9.3 months. The 2-year PFS rate was 41%, and the 2-year OS rate was 74%. The extent of liver metastatic disease correlated with a worse PFS (P = .01 by log-rank test) and a worse OS (P < .0001 by log-rank test). Analyses showed that metastatic replacement of more than 75% of the liver and prior chemotherapy were independently associated with inferior PFS.

CONCLUSION

Patients with locally advanced or metastatic PEC who are treated with FAS may have a reasonable RR, and responders may experience longer PFS and OS. The volume of metastases in the liver is the most important predictor of outcome.

Surgery of resectable nonfunctioning neuroendocrine pancreatic tumors

Nonfunctioning neuroendocrine pancreatic tumors (NFNEPTs) comprise about one-third of pancreatic endocrine tumors. Based on immunohistochemistry, nonfunctioning tumors are difficult to distinguish from functioning ones; therefore the final diagnosis is basically the result of a synopsis of pathology and clinical data. Owing to their incapacity to produce hormone-dependent symptoms, NFNEPTs are detected incidentally or because of uncharacteristic symptoms resulting from local or distant growth. About two-thirds of NFNEPTs are located in the pancreatic head, so jaundice may be a late symptom of this tumor. Modern diagnostic procedures are best applied by a stepwise approach: first endoscopic ultrasonography and computed tomography/magnetic resonance imaging followed by somatostatin receptor scintigraphy or positron emission tomography (or both). Due to significant false-positive and false-negative findings, for decision-making the latter should be confirmed by a second imaging modality. Regarding indications for surgery and the surgical approach to the pancreas, three pancreatic manifestations of NFNEPTs can be distinguished: (1) solitary benign non-multiple endocrine neoplasia type 1 (non-MEN-1); (2) multiple benign MEN-1; and (3) malignant NFNEPTs. Reviewing the literature and including our experience with 18 NFNEPTs (8 benign, 10 malignant) reported here, the following conclusions can be drawn: (1) Solitary benign non-MEN-1 NFNEPTs can be removed by enucleation or by pancreas-, spleen-, and duodenum-preserving techniques in most cases. The choice of surgical technique depends on the location and site of the tumor and its anatomic relation to the pancreatic duct. (2) With multiple benign MEN-1 NFNEPTs, because of the characteristics of the underlying disease a preferred, more conservative concept (removal of only macrolesions) competes with a more radical procedure (left pancreatic resection with enucleation of head macrolesions). Further studies are necessary to clarify the best way to balance quality of life (by preserving organ function) with growth control of potentially malignant tumors in the pancreas. (3) Malignant NFNEPTs comprise more than half of all NFNEPTs. Few studies have analyzed treatment strategies for localized or metastatic tumors. Whereas radical (including multivisceral) resection of tumors without distant metastases is widely accepted, the indication for radical surgery on metastasizing tumors has been questioned, as radical removal of the primary tumor may fail to increase survival. Adjuvant regimens in these tumor stages are mandatory and should be further optimized.

ACTH-secreting islet cell tumor of the pancreas presenting as bilateral ovarian tumors and Cushing's syndrome

A 41-year-old woman presented with hirsutism, a pelvic mass, and Cushing's syndrome. Imaging studies revealed bilateral ovarian masses and a solid and cystic mass within the pancreas. Partial pancreatectomy, bilateral oophorectomy, and excision of several peritoneal tumor nodules were performed. Pathological examination revealed a neuroendocrine islet cell tumor of the pancreas with bilateral ovarian metastases. The tumor was immunoreactive for ACTH, chromogranin, neuron-specific enolase, and keratin. The patient received postoperative chemotherapy and has been disease-free for 6 years. To our knowledge, this is the first reported case of an ACTH-secreting pancreatic neuroendocrine tumor presenting as bilateral ovarian metastases.

Parathyroid hormone-related peptide in pancreatic neuroendocrine tumours associated with hypercalcaemia

BACKGROUND

Hypercalcaemia is a common paraneoplastic syndrome. In the context of pancreatic neuroendocrine tumours, it is occasionally caused by secretion of parathyroid hormone-related peptide (PTH-rP).

CASE OUTLINES

Two patients are reported in whom persistent hypercalcaemia was traced to a large neuroendocrine pancreatic tumour hypersecreting PTH-rP. Resection of the tumour reduced serum levels of calcium and PTH-rP transiently in each case until the patient developed bulky metastatic disease. A 33-year-old woman remained hypercalcaemic after the removal of all four hyperplastic parathyroid glands had rendered circulating parathormone levels undetectable. Radical distal pancreatectomy was followed over the next 4 years by operative debulking of liver metastases, multiple hepatic artery embolisations, octreotide injections and repeated admissions for intravenous fluid and biphosphonate therapy. A 41-year-old man presented with hypercalcaemia as well as features of somatostatinoma syndrome. Symptomatic improvement after radical distal pancreatectomy was short-lived, and hepatic artery embolisation failed to control his rapidly progressive disease.

DISCUSSION

Malignant hypercalcaemia associated with a neuroendocrine pancreatic tumour hypersecreting PTH-rP is difficult to treat and can be life-threatening. Aggressive surgical treatment is recommended initially, while somatostatin analogues and hepatic artery embolisation are alternative therapeutic options for metastatic disease.

Zollinger-Ellison syndrome. Clinical presentation in 261 patients

We prospectively evaluated the initial presenting symptoms in 261 patients with Zollinger-Ellison syndrome (ZES) over a 25-year period. Twenty-two percent of the patients had multiple endocrine neoplasia-type 1 (MEN-1) with ZES. Mean age at onset was 41.1 +/- 0.7 years, with MEN-1 patients presenting at a younger age than those with sporadic ZES (p < 0.0001). Three percent of the patients had onset of the disease < age 20 years, and 7% > 60 years. A mean delay to diagnosis of 5.2 +/- 0.4 years occurred in all patients. A shorter duration of symptoms was noted in female patients and in patients with liver metastases. Abdominal pain and diarrhea were the most common symptoms, present in 75% and 73% of patients, respectively. Heartburn and weight loss, which were uncommonly reported in early series, were present in 44% and 17% of patients, respectively. Gastrointestinal bleeding was the initial presentation in a quarter of the patients. Patients rarely presented with only 1 symptom (11%); pain and diarrhea was the most frequent combination, occurring in 55% of patients. An important presenting sign that should suggest ZES is prominent gastric body folds, which were noted on endoscopy in 94% of patients; however, esophageal stricture and duodenal or pyloric scarring, reported in numerous case reports, were noted in only 4%-10%. Patients with MEN-1 presented less frequently with pain and bleeding and more frequently with nephrolithiasis. Comparing the clinical presentation before the introduction of histamine H2-receptor antagonists (pre-1980, n = 36), after the introduction of histamine H2-receptor antagonists (1981-1989, n = 118), and after the introduction of proton pump inhibitors (PPIs) (> 1990, n = 106) demonstrates no change in age of onset; delay in diagnosis; frequency of pain, diarrhea, weight loss; or frequency of complications of severe peptic disease (bleeding, perforations, esophageal strictures, pyloric scarring). Since the introduction of histamine H2-receptor antagonists, fewer patients had a previous history of gastric acid-reducing surgery or total gastrectomy. Only 1 patient evaluated after 1980 had a total gastrectomy, and this was done in 1977. The location of the primary tumor in general had a minimal effect on the clinical presentation, causing no effect on the age at presentation, delay in diagnosis, frequency of nephrolithiasis, or severity of disease (strictures, perforations, peptic ulcers, pyloric scarring). Disease extent had a minimal effect on symptoms, with only bleeding being more frequent in patients with localized disease. Patients with advanced disease presented at a later age and with a shorter disease history (p = 0.001), were less likely to have MEN-1 (p = 0.0087), and tended to have diarrhea more frequently (p = 0.079). A correct diagnosis of ZES was made by the referring physician initially in only 3% of the patients. The most common misdiagnosis made were idiopathic peptic ulcer disease (71%), idiopathic gastroesophageal reflux disease (GERD) (7%), and chronic idiopathic diarrhea (7%). Other less common misdiagnosis were Crohn disease (2%) and various diarrhea diseases (celiac sprue [3%], irritable bowel syndrome [3%], infectious diarrhea [2%], and lactose intolerance [1%]). Other medical disorders were present in 55% of all patients; patients with sporadic disease had fewer other medical disorders than patients with MEN-1 (45% versus 90%, p < 0.00001). Hyperparathyroidism and a previous history of kidney stones were significantly more frequent in patients with MEN-1 than in those with sporadic ZES. Pulmonary disorders and other malignancies were also more common in patients with MEN-1. These results demonstrate that abdominal pain, diarrhea, and heartburn are the most common presenting symptoms in ZES and that heartburn and diarrhea are more common than previously reported. The presence of weight loss especially with abdominal pain, diarrhea, or heartburn is an important clue suggesting the presence of gastrinoma. The presence of prominent gastric body folds, a clinical sign that has not been appreciated, is another important clue to the diagnosis of ZES. Patients with MEN-1 presented at an earlier age; however, in general, the initial symptoms were similar to patients without MEN-1. Gastrinoma extent and location have minimal effects on the clinical presentation. Overall, neither the introduction of successful antisecretory therapy nor widespread publication about ZES, attempting to increase awareness, has shortened the delay in diagnosis or reduced the incidence of patients presenting with peptic complications. The introduction of successful antisecretory therapy, however, has dramatically decreased the rate of surgery in controlling the acid secretion and likely led to patients presenting with less severe symptoms and fewer complications. (ABSTRACT TRUNCATED)

Nonfunctioning islet cell carcinoma of the pancreas with high serum CEA & CA19-9, K-ras codon 12 mutation, and microsatellite instability

A 55-year-old man with nonfunctioning islet cell carcinoma showing elevation of serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels is described with genetic analyses. Pathological examination of the resected specimen revealed two independent islet cell carcinomas, one in the body and the other in the tail of the pancreas. It was proved immunohistochemically that the tumor cells, particularly those in the tail, were immunoreactive to CEA and CA 19-9 and had the property of duct cells, as well as endocrine cells. Gastrin was demonstrated immunohistochemically in these tumor cells, although its level in serum was not elevated. Genetic analyses of the fresh specimens from the tumor in the body revealed K-ras codon 12 mutation and microsatellite instability. These findings are consistent with its progressive clinical course and strongly suggest that these tumors originate, not from the islet cells of Langerhans, but from protodifferentiated cells, capable of giving rise to all the pancreatic cell types.

Pancreatic serous cystadenoma associated with islet cell tumour

We report the case of a 29-year-old female patient with a diffuse type of serous cystadenoma involving the entire pancreas except for part of the head, which was replaced by islet cell tumour. Ultrasound and CT showed multiple cysts in the entire pancreas and a solid mass with calcification in the head. MRI characterized the fluid content of the cysts and the extent of disease.

Protocol for the examination of specimens from patients with endocrine tumors of the pancreas, including those with mixed endocrine and acinar cell differentiation: a basis for checklists. Cancer Committee of the College of American Pathologists

No Abstract Available

Necrolytic migratory erythema, first symptom of a malignant glucagonoma: treatment by long-acting somatostatin and surgical resection. Report of three cases

We report three cases of malignant glucagonoma with necrolytic migratory erythema as the first clinical symptom. Long-acting somatostatin analogue was the first step of a multimodal therapeutic strategy which included surgical resection of the primary tumour in every case. Liver metastases which were present in two patients were treated by hepatic arterial chemoembolization and systemic chemotherapy in one case and by liver resection for cytoreduction and hepatic arterial chemoembolization in another case. Skin lesions resolved in all three patients.

Prognostic factors in patients with endocrine tumours of the duodenopancreatic area

BACKGROUND

The development of endocrine tumours of the duodenopancreatic area (ETDP) is thought to be slow, but their natural history is not well known. The aim of this study was to determine the factors that influence survival of patients with ETDP.

PATIENTS/METHODS

Eighty two patients with ETDP (44 non-functioning tumours, 23 gastrinomas, seven calcitonin-secreting tumours, four glucagonomas, three insulinomas, one somatostatinoma) followed from October 1991 to June 1997 were included in the study. The following factors were investigated: primary tumour size, hormonal clinical syndrome, liver metastases, lymph node metastases, extranodular/extrahepatic metastases, progression of liver metastases, local invasion, complete resection of the primary tumour, and degree of tumoral differentiation. The prognostic significance of these factors was investigated by uni- and multi-variate analysis.

RESULTS

Twenty eight patients (34%) died within a median of 17 months (range 1-110) from diagnosis. Liver metastases (p = 0.001), lymph node metastases (p = 0.001), progression of liver metastases (p < 0.00001), lack of complete resection of the primary tumour (p = 0.001), extranodular/extrahepatic metastases (p = 0.001), local invasion (p = 0.001), primary tumour size > or = 3 cm (p = 0.001), non-functioning tumours (p = 0.02), and poor tumoral differentiation (p = 0.006) were associated with an unfavourable outcome by univariate analysis. Multivariate analysis identified only liver metastases (risk ratio (RR) = 8.3; p < 0.0001), poor tumoral cell differentiation (RR = 8.1; p = 0.0001), and lack of complete resection of the primary tumour (RR = 4.8; p = 0.0007) as independent risk factors. Five year survival rates were 40 and 100% in patients with and without liver metastases, 85 and 42% in patients with and without complete resection of primary tumour, and 17 and 71% in patients with poor and good tumour cell differentiation respectively.

CONCLUSION

Liver metastases are a major prognostic factor in patients with ETDP. Progression of liver metastases is also an important factor which must be taken into account when deciding on the therapeutic approach. The only other independent prognostic factors are tumoral cell differentiation and complete resection of the primary tumour.

Clinical spectrum of hyperglucagonemia associated with malignant neuroendocrine tumors

OBJECTIVE

To review the clinical features associated with hyperglucagonemia in malignant neuroendocrine tumors.

MATERIAL AND METHODS

We retrospectively reviewed the medical records of patients with hyperglucagonemia encountered at our institution from Oct. 17, 1988, through February 1993 who had a fasting serum glucagon level of at least 120 pg/mL (twice the normal value). The 71 study patients also had no evidence of a secondary cause of hyperglucagonemia and had pathologic confirmation of a neuroendocrine tumor.

RESULTS

The study group consisted of 46 men and 25 women with a median age of 57 years. Two patients had multiple endocrine neoplasia. Forty-nine patients had biochemically polyfunctional tumors, and 22 had hyperglucagonemia only. The most common initial symptoms were weight loss, abdominal pain, diarrhea, nausea, peptic ulcer disease, diabetes, and necrolytic migratory erythema (NME). Diabetes eventually developed in 25 patients and was associated with NME in 11. The highest median serum glucagon values occurred in patients with the glucagonoma syndrome or insulinomas, and the lowest median values were in those with carcinoid syndrome, Zollinger-Ellison syndrome, or diabetes without NME. Fasting glucagon and glucose measurements were not correlated. The most common hormonal syndromes were the Zollinger-Ellison syndrome and the glucagonoma syndrome. All the neuroendocrine tumors were malignant. Several methods of treatment, including surgical debulking, chemotherapy, somatostatin, and hepatic artery embolization, were used. Death occurred in 29 patients at a median of 2.79 years after diagnosis; 42 patients were alive at a median of 2.86 years after diagnosis.

CONCLUSION

A mild degree of hyperglucagonemia can commonly be associated with multifunctional neuroendocrine tumors. The glucagonoma syndrome occurs in a few patients with malignant neuroendocrine tumors and hyperglucagonemia and is associated with very high serum glucagon levels. The correlation between serum glucagon levels and the development of diabetes is limited, and other factors such as insulin may be more important than hyperglucagonemia in the development of diabetes.

Fine-needle aspiration cytology of islet cell tumors

Islet cell tumors of the pancreas are neuroendocrine neoplasms whose biologic behavior has been well characterized. Frequently, these tumors produce one or more hormones which may strongly affect the patients' clinical presentation. In this study, we have examined fine-needle aspirates (FNA) from 13 islet cell tumors and have summarized their cytomorphologic appearances. The smears prepared from aspirates of the islet cell tumors displayed loose cellular arrangements and numerous single cells, with most cases demonstrating a predominance of single cells over the loose groups. An important diagnostic feature was the uniform appearance of the neoplastic cells. Nuclei were small to moderate in size, always round to oval in shape, and frequently contained small nucleoli. In 11 cases, the nuclear chromatin pattern was finely granular and evenly-distributed while in two cases the chromatin was coarser. Eccentrically located nuclei were commonly found and binucleated cells were seen in one-half of the aspirates. At least a moderate amount of finely granular cytoplasm was always identifiable. Immunocytochemical stains for neuron-specific enolase were positive in all five of our cases in which staining for this marker was attempted and chromogranin was positive in five of six cases. Generally, our cytomorphologic observations were supported by the findings of other investigators as reported in the cytology literature. The cytomorphologic characteristics of islet cell tumors are distinctive, and appropriate ancillary studies can be used to support the FNA diagnosis of this entity.

A retrospective study of pancreatic tumors in slaughter cattle

Sixteen primary pancreatic tumors were found in a retrospective study of bovine pancreatic lesions detected in slaughtered cattle. Eleven islet cell tumors and three pancreatic exocrine carcinomas were identified based on light microscopy and immunohistochemistry. Nine of 11 islet cell tumors were classified as malignant. Metastatic sites included iliac, mediastinal, hepatic, and mesenteric lymph nodes, peritoneum, mesentery, and liver. Six cows with multiple islet cell tumors also had pheochromocytomas. All 11 islet cell tumors had positive immunoreactivity to insulin and somatostatin. Three tumors also contained cells immunoreactive for glucagon and two tumors contained pancreatic polypeptide immunoreactive cells. Immunoreactivity of tumor cells in metastatic sites was similar to their respective primary tumors. All exocrine pancreatic carcinomas metastasized widely and were immunonegative for insulin, somatostatin, glucagon, and pancreatic polypeptide. No mixed endocrine-exocrine tumors were identified. None of the endocrine or exocrine tumors contained amyloid. Additional primary tumors of the bovine pancreas included one neurofibroma and one neurofibrosarcoma. Additional cases with lesions of the bovine pancreas included nodular hyperplasia in 15 cows, exocrine acinar atrophy and fibrosis in four cows (two of which also had pancreatic lithiasis), pancreatitis in one cow, peripancreatic fibrosis in two cows, pancreatic steatosis in one animal, and pancreatic hemorrhages in one cow.

Multiple intracerebral metastases from an islet cell carcinoma of the pancreas: case report

Computed tomography and magnetic resonance imaging of an 85-year-old woman with bitemporal headaches revealed cystic lesions in the basal ganglia and cerebellum. The patient remained neurologically asymptomatic until just before her death at age 89. Autopsy revealed tumors of the brain, lungs, liver, periaortic lymph nodes, adrenal gland, and the pancreas. Light microscopy demonstrated a malignant small cell tumor with scant cytoplasm. Electron microscopy revealed intracytoplasmic dense core vesicles, characteristic of neuroendocrine tumors, which prompted the diagnosis of islet cell carcinoma. All lesions were found to be microscopically similar. Previous reports of islet cell carcinoma metastatic to the brain could not be found. This case emphasizes the importance of electron microscopy in cases of small cell neoplasms in the brain.

Determinants of metastatic rate and survival in patients with Zollinger-Ellison syndrome: a prospective long-term study

BACKGROUND/AIMS

It is unclear whether tumor location, size, or the presence of multiple endocrine neoplasia type 1 (MEN-1) alters metastatic rate and survival in patients with pancreatic endocrine tumors. The purpose of this study was to determine the prognostic factors of survival and metastatic rate in patients with Zollinger-Ellison syndrome (ZES).

METHODS

Data were analyzed from 185 consecutive patients with ZES who were followed up prospectively.

RESULTS

Liver metastases were present in 24% of patients and correlated with the size of the primary tumor. Duodenal tumors were smaller than pancreatic tumors. Liver metastases occurred more often (P < 0.00001) with pancreatic than duodenal tumors, whereas the metastatic rate to lymph nodes was not different. Survival of patients with liver but not lymph node metastases was shortened. In patients with sporadic ZES, liver metastases were more common during the initial evaluation and survival was decreased compared with patients with MEN-1; however, during follow-up, an equal percentage of patients with and without MEN-1 developed liver metastases.

CONCLUSIONS

Survival was primarily determined by the presence of liver metastases. The frequency of liver metastases depends on the size and location of the primary tumor and on the presence of MEN-1 at the initial presentation. Metastases to the lymph nodes do not depend on these factors. A benign and malignant form of ZES exists.

Malignant islet cell tumor associated with hypercalcemia

BACKGROUND

Three cases of islet cell tumors of the pancreas with hypercalcemia were studied, and 16 similar cases have been found in a 25-year review of the English-language literature. The purpose of the study was to review the cause of the hypercalcemia and the clinical characteristics of the tumors.

METHODS

Tumor tissue retrieved from paraffin-embedded blocks was studied immunohistochemically for both parathyroid hormone (PTH) and PTH-related protein (PTHrP). PTH was measured in the serum in each patient and the serum PTHrP was measured by immunoassay in one patient.

RESULTS

One of our patients had a fatal serum calcium level of 26.4 mg/dl. PTHrP stains were positive in two of our tumors, and one patient had an elevated PTHrP serum level. Serum PTH levels were normal or low in each patient. All three tumors were malignant and extremely vascular. The total group of 19 patients have in common hypercalcemia associated with a normal or low serum PTH level. Although the cause of hypercalcemia has not been proved, the tumors apparently produce PTHrP, because seven of eight tumors stained positive for PTHrP and each of the four patients tested had an elevated PTHrP serum titer. The tumors are extremely vascular, are usually malignant (17 of 18), and become large, but they are compatible with a relatively long patient survival time.

CONCLUSIONS

These neuroendocrine tumors associated with hypercalcemia share several characteristics, but a claim that they represent another type of "functioning islet cell tumor" should await a clearer delineation of the cause of the hypercalcemia.

Embryologic concepts in the APUD system

The amalgamation of the neural and endocrine physiologic mechanisms for functional homeostasis as a neuroendocrine system is brought into focus in this chapter on the embryologic concepts in the APUD system. The neuroendocrine system, now regarded as the third division of the nervous system, is a regulatory mechanism that links the functions of the autonomic nerves and the endocrine cells throughout the body. The current realization that both neural and endocrine actions are often involved in the clinical manifestations of many syndromes is clarified by the theories on the embryologic origin of the APUD system described here. Relevant historical developments, as well as cytochemical discoveries, have been gradually integrated into the evolving theories of the embryologic origin of the APUD system. These theories have not been without controversy, but new developments stimulate new concepts and, as new investigative tools have produced a plethora of new information that continues to push investigators, basic and clinical into new horizons, earlier theories have been modified and new theories have been developed. These theories are reviewed in chronological order in this chapter.

Giant nonfunctioning islet cell tumor requiring pancreaticoduodenectomy and complete liver revascularization

Pancreaticoduodenectomy with revascularization of the hepatic artery and portal vein was performed on a 17-year-old girl with giant nonfunctioning islet cell tumor of the pancreas. She had a remote history of neonatal hypoglycemia leading to mental retardation and a right Wilms' tumor resected at 8 months. Serum pancreatic polypeptide levels were elevated. Her postoperative course was complicated by an ischemic perforation of the colon, which did not infect her prosthetic vascular grafts. The relationship between her neonatal hypoglycemia, Wilms' tumor, and subsequent islet cell neoplasm is unclear.

Use of octreotide acetate for control of symptoms in patients with islet cell tumors

Gut tumor syndromes are rare, occurring in less than two cases per million population per year: Insulinomas are most common and gastrinomas are less common; all the others are extremely rare. Conventional treatment of the symptoms caused by these tumors has included surgery, hepatic arterial embolization, and chemotherapy; some patients with Zollinger-Ellison syndrome (ZES) have been treated with specific agents such as gastric antisecretory drugs. The development of octreotide, a synthetic, long-acting analogue of the natural peptide somatostatin, has offered an alternative to such therapies. Octreotide has a half life of > 100 minutes and inhibits both physiological- and tumor release of many peptides. It also has direct effects on the gut that modify secretion and motility. Octreotide has been shown to be particularly useful for the symptoms of tumors producing vasoactive intestinal peptide (VIP), and of the carcinoid syndrome. It is also useful in patients with glucagonomas, with growth hormone-releasing hormone producing tumors, and in some patients with Cushing's syndrome and unresectable insulinomas. Octreotide is effective in patients with ZES, but alternative therapies such as omeprazole are more effective, safer, and more convenient for those patients. Side effects of octreotide have not been troublesome in these patients, but the incidence of long term effects is still not entirely clear. Octreotide has proved to be a significant advance in the treatment of patients with islet cell tumors.

Clinical characteristics, treatment and survival in patients with pancreatic tumors causing hormonal syndromes

Eighty-five patients with endocrine pancreatic tumors associated with clinical syndromes of hormone excess were retrospectively analyzed regarding symptomatology, means of diagnosis, and results of surgical and medical treatment during follow-up of 3-18 years (median 8 years). The combination of angiography and computed tomography was most successful in pre-operative localization of both primary tumors and metastases. Surgery provided long term cure in 39 of 44 patients with benign islet cell lesions, the majority having insulinomas. Forty-one patients had malignant tumors, which at the time of diagnosis or operation were associated with liver and/or regional lymph gland metastases in 56% and 24%, respectively. Sixteen patients with metastatic disease and/or very large tumors were considered inoperable, 5 patients underwent palliative resection of their malignant tumors, while grossly radical tumor removal was accomplished in 20 patients. Long-term cure was achieved in 5 patients by excision of primary tumors and localized liver or lymph gland metastases. Half of the patients, particularly those with insulinoma, gastrinoma, or vipoma, showed response to streptozotocin, in combination with other cytostatics, for a median of 24 months or a response to interferon for a median of 10 months. The overall 5-year and 10-year survival among the patients with malignant islet cells tumors was 54% and 28%, respectively. Absence of liver metastases at time of operation/diagnosis, smaller size of the primary tumor, grossly radical tumor resection as well as response to medical therapy predicted the more favorable survival.

Cystic pancreatic glucagonoma in contact with insulinoma found in a hypoglycemic patient

Cystic glucagonoma in contact with insulinoma was found in the pancreas of a 28-year-old female patient with characteristic hypoglycemic syndrome. Among six tumors in total detected in the tail of the resected pancreas, the largest solid tumor (2.5 cm in diameter) consisted mostly of insulin-containing cells with conspicuous amyloid deposition. Contiguous to this tumor, the second largest nodule, measuring 1.8 cm in diameter, showed cystic changes and consisted of glucagon-containing cells. High concentration of immunoreactive glucagon was demonstrated in the cystic fluid. In addition to the cystic changes of endocrine pancreatic tumors, simultaneous occurrence of glucagonoma in contact with insulinoma appears to be extremely rare and repeated episodes of hypoglycemia may contribute to its pathogenesis.

Loss of heterozygosity on chromosome 11 in sporadic gastrinomas

Gastrinomas are pancreatic endocrine neoplasms that arise either sporadically or are inherited as part of the multiple endocrine neoplasia type I syndrome (MENI). Loss of heterozygosity (LOH) in the region flanking the MENI gene at chromosome 11q13 has been documented in a few sporadic and familial pancreatic endocrine tumors, but not previously in sporadic gastrinomas. It has therefore been suggested that gastrinomas develop by a mechanism different from other tumors associated with the MENI syndrome. We report LOH on chromosome 11 in 5 of 11 sporadic gastrinomas. Four of these tumors have LOH for markers flanking the MENI region. Molecular evaluation of segments of chromosomes 3, 13, and 17 known to contain cloned or putative tumor suppressor genes fail to show LOH except at one locus in one tumor. These data suggest that a tumor suppressor DNA segment exists at 11q13 that may be involved in the development of sporadic gastrinomas.

Hyperinsulinaemia causes a preferential increase in hepatic P4501A2 activity

Male NEDH (New England Deaconess Hospital) rats were transplanted with a radiation-induced tumour from a donor male rat and were killed 18 days following transplantation. At the time of killing the insulinoma-bearing animals were severely hypoglycaemic but plasma ketone levels were normal. Insulinoma-bearing animals exhibited higher hepatic O-deethylation of ethoxyresorufin and N-demethylation of ethylmorphine activities when compared to control animals. Similarly, hepatic microsomal preparations from insulinoma-bearing rats were more efficient than control animals in converting the promutagen 2-amino-6-methyldipyrido[1,2-a:3',2']imidazole (Glu-P-1) to mutagenic intermediates in the Ames test. Immunoblot analysis employing polyclonal antibodies against the P4501A and P453A families revealed that insulinoma-bearing rats had higher hepatic P4501A2 apoprotein levels. No major differences in P4503A1 apoprotein levels between insulinoma-bearing and control rats were noted. Subcutaneous administration of insulin to male Wistar rats gave rise to a modest increase in ethoxyresorufin O-deethylase activity and in the ability to activate Glu-P-1 to mutagens in the Ames test. Immunoblot analysis revealed an increase in hepatic P4501A2 apoprotein levels following the treatment with insulin. It is concluded that insulinoma-bearing rats display high P4501A2 activity and the hyperinsulinaemia that characterize this condition is responsible for the effect. Moreover, administration of insulin to other strains of rat, such as Wistar, also enhances P4501A2 activity, presumably as a result of hyperinsulinaemia.

Curative resection in Zollinger-Ellison syndrome. Results of a 10-year prospective study

Since 1980, 73 patients with Zollinger-Ellison syndrome (ZES) without radiographic evidence of liver metastases were studied on a prospective protocol including medical management of gastric acid hypersecretion, extensive radiographic tumor localization, and exploratory surgery to find and resect gastrinoma for potential cure. Each patient had gastric acid hypersecretion effectively controlled with either H2-blockers or omeprazole. Patients were divided prospectively into two groups, with all patients undergoing the same preoperative localization studies and extensive laparotomy. In contrast to group 1 (1980-1986) (36 patients), group 2 (1987-Oct. 1990) (37 patients) also underwent additional procedures (transillumination and duodenotomy) at surgery to find duodenal gastrinomas. Preoperative imaging studies localized tumor in 38 (52%) patients, and portal venous sampling for gastrin determinations was positive in 49 (67%) patients. Gastrinomas were found and resected in 57 (78%) patients. Significantly more gastrinomas (92% of patients) were found in group 2 than in group 1 patients (64%) (p less than 0.01). This increase was due to increased numbers of duodenal gastrinomas in group 2 than in group 1 patients (43% versus 11%; p less than 0.01). The increased ability to find duodenal gastrinomas did not significantly improve the immediate disease-free rate, which was 58% for all patients. Duodenal primary gastrinomas were found to have a significantly greater incidence of metastases (55%) and a significantly shorter disease-free interval (12 months) than pancreatic gastrinomas (22% and 84 months, respectively) suggesting that duodenal gastrinomas may be more malignant and not more frequently curable than pancreatic gastrinomas. Operations were performed with no deaths and 11% morbidity rate. Long-term follow-up showed that 50% of patients initially rendered disease free would develop recurrent disease by 5 years. Survival was excellent for all patients, and none died of malignant spread of the tumor or uncontrolled peptic ulcer disease, with a mean follow-up of 5 years. This finding is in contrast to patients who presented with metastatic disease on imaging studies and had a 20% 5-year survival rate. This study suggests that all patients with localized sporadic ZES can have the gastric acid hypersecretion managed medically, that overall survival of these patients is excellent, most (78%) can have all gastrinoma found and resected, and some (30%) will be cured (long-term disease-free survival).

Four year treatment with a long acting somatostatin analogue in a patient with Verner-Morrison syndrome

The case is described of a woman with a Verner-Morrison syndrome of extreme severity, caused by an occult VIPoma. Administration of SMS 201-995 (Sandoz) (SMS) at the dose of 150 and subsequently of 250 micrograms daily, decreased plasma levels of vasoactive intestinal polypeptide (VIP) from about 500 to 100 pg/ml (highest normal limit 60 pg/ml). This was associated with complete regression of the diarrhea and normalization of serum potassium levels and hence with the return of the patient to a fully normal life. After 36 months of clinical remission, watery diarrhea recurred together with elevation of VIP plasma levels and appearance of liver metastases. Laparotomic exploration led to the removal of a pancreatic VIPoma and its liver secondarisms, which was followed by a second remission. Reappearance of the symptoms and development of new liver metastases 8 months later required reinstitution of SMS therapy, which allowed once again to control the clinical picture. Anterior pituitary function, assessed by dynamic testing, was unaffected by chronic SMS administration with the exception of the stimulated growth hormone secretion that was inhibited. Glucose tolerance and insulin secretion remained normal during treatment. Glucose intolerance ensued after pancreatectomy and was not worsened by reintroduction of SMS. Treatment with SMS may allow long-lasting remission of Verner-Morrison syndrome associated to VIPoma, though it does not arrest the progression of the tumor.

Unresolved surgical issues in the management of patients with Zollinger-Ellison syndrome

In the last 10 years, there have been a number of major advances that have markedly changed the management of patients with Zollinger-Ellison syndrome. These advances have been described recently in a number of excellent reviews. After reading each of these reviews, including our own, one is left generally with the impression that most of the important problems and particularly those involving surgery in the treatment of this disease have been resolved; however, in considering the possible problems to address in protocols in the coming years in our patients with Zollinger-Ellison syndrome followed at the National Institutes of Health, it became apparent to us that not only will surgery play an increasingly important role in the management of this disease, but that there are a number of major questions in which various aspects involving surgery are not resolved. Furthermore, resolution of a number of these areas will have applicability to the surgical treatment of other islet cell tumors. The purpose of this article is to call attention to these questions with the hope that other investigators may also consider these and specifically attempt to address some of these issues in the surgical treatment of Zollinger-Ellison syndrome in prospective studies.

Anesthesia for glucagonoma resection

Anesthetic experience with three cases of the resection of glucagonoma, a rare tumor of alpha cells of pancreatic islets, is presented. Marked increases of blood glucagon and glucose levels, with the potential for clinically significant metabolic and myocardial dysfunction, did not occur during anesthesia and surgery. Associated tumors of other endocrine cell types also were absent in the three study patients. Strategies for anticipating and managing other perioperative problems associated with glucagonoma also are discussed.

Localization and peptide content of endocrine pancreatic tumors

Endocrine pancreatic tumors contain and frequently secret neurohormonal peptides. This phenomenon can be used as a diagnostic and classifying tool. This study analyzes 31 patients operated on because of an endocrine pancreatic tumor, including the diagnostic procedures and the localization methods. In 15 insulinoma cases only 6 patients had a positive arteriography, while all 11 selective pancreatic vein samplings were positive. The immunoreactivity showed that, besides insulin, most tumors also contained other peptides. Of four gastrinoma cases the arteriography was positive in three, but the selective vein sampling localized the tumor in all. The tumor's content of peptides showed mixed patterns. In the four glucagonomas, the arteriography was positive in all and the venous sampling performed in three of the cases also was positive. In five pancreatic polypeptide-containing tumors (PP-omas) the arteriography was positive in four and sampling performed in two was positive in both. In the PP-omas the peptide pattern showed that these tumors frequently contain several peptides. We used selective pancreatic vein sampling in 21 cases with positive result in all. In the cases in which arteriography was negative, the sampling results helped the surgeon to find the tumor. The peptide pattern in the tumors varied greatly and most tumors were multihormonal.

Parathyroid hormone-related protein and hypercalcemia in pancreatic neuro-endocrine tumors

We investigated the possible involvement of parathyroid hormone-related protein (PTHrP) in 2 cases of metastatic pancreatic neuro-endocrine tumors associated with severe hypercalcemia. Both patients displayed biochemical alterations in renal tubular reabsorption of calcium and phosphate, as well as in urinary cAMP excretion, similar to those encountered in primary hyperparathyroidism, although plasma levels of parathyroid hormone were within the normal range. Tumor protein extracts stimulated cAMP production, which was inhibited by the PTH-antagonist (8,18 Nle, 34 Tyr)bPTH-(3-34)amide, in the PTH-responsive osteoblastic cell line UMR-106. Northern blot analysis of tumor extracts revealed the presence of PTHrP mRNA transcripts, while PTH mRNA was undetectable. In contrast, neither PTHrP mRNA(s) nor cAMP-stimulating activity was detectable in other neuroendocrine tumors not accompanied by hypercalcemia. These results demonstrate that certain pancreatic neuroendocrine tumors associated with hypercalcemia can synthesize and release PTHrP.