[Pancreatic endocrine tumors]

Incidence of the endocrine tumors of the pancreas is about 4 to 10/1.000.000 peoples. We present 10 cases of endocrine pancreatic tumors which were operated in the First Surgical Clinic Iaşi in the last 20 years (1984-2003); these cases represent about 2.21% from all the pancreatic tumors (454 cases). It was 4 insulinoma, 2 gastrinoma, 2 gastrinoma associated with other endocrine neoplasia (Wermer syndrome) and 2 non-functioning endocrine pancreatic tumors. Female/men ratio was 9/1 and median age was about 41.9 yo (27-67 yo). In the four cases of insulinoma (all females) the diagnosis was delayed by two to five years due to misinterpretation of neurological symptoms generated by hypoglycemia. The diagnosis of insulinoma was based on Whipple triad, high plasma insulin levels associated with low plasma glucose levels, as well as the symptomatic relief after intravenous glucose injection. The surgical option was based on biological data, ultrasonography, computed tomography and arteriography. In two cases the localization of the insulinoma was established only by intraoperative ultrasonography. All tumors were localized in the tail of pancreas. In three cases we decided for a distal pancreatic resection with splenectomy and in one case for spleen preserving left pancreatectomy. Postoperative course was uneventful and all the symptoms disappeared. The diagnosis was confirmed on pathological examination in all cases. We also present two cases of gastrinoma with multiple ulcers and multiple surgical interventions for haemorrhage and perforation with peritonitis. Both patients died and diagnosis of pancreatic endocrine tumors was post-mortem. The two patients with Wermer syndrome also had ulcers complicated with haemorrhage and peritonitis and parathyroid adenoma. One case also had ante-hypophyseal and pituitary adenoma and the other had thyroid colloid hypertrophy. We performed left pancreatectomy with spleen preservation in one case and enucleation associated with total gastrectomy in the second case. The two cases of non-functioning pancreatic endocrine tumors had a non-specific symptoms. Diagnostic was established by abdominal ultrasound exam. We performed spleno-pancreatectomy in one case and pancreatectomy with spleen preservation in the other patient. Postoperative course was un-eventful.

[Pseudo Zollinger-Ellison syndrome in a patient with duodenal stenosis caused by tuberculosis]

We report the case of a 32-year-old Indian man with symptoms suggesting Zollinger-Ellison syndrome including abdominal pain, esaphagitis, duodenal stenosis that did not improve with antisecretory medication, elevated fasting gastrin serum levels that increased after intravenous secretin injections, elevated chromogranin A serum levels and tumoral aspect of pancreatic uncus on CT scan examination. A pancreaticoduodenectomy was performed. Histological examination of the resected specimen showed that there was no endocrine tumour of the pancreas or the duodenum, but identified marked lesions of follicular and caseous tuberculosis. The final diagnosis retained pseudo Zollinger-Ellison syndrome due to gastric outlet obstruction caused by duodenal stenosis of a tuberculosis origin.

Zollinger-Ellison syndrome in 2006: concepts from a clinical point of view

Zollinger-Ellison syndrome (ZES) is characterised by peptic ulcers of the upper gastrointestinal tract failing to heal despite maximal medical therapy, diarrhoea and marked gastric acid hypersecretion associated with a gastrin-secreting tumour (gastrinoma). ZES might be associated with multiple endocrine neoplasia type 1. The main diagnostic features are hypergastrinemia and acid hypersecretion. When these parameters give borderline results, provocation test (with secretin or calcium) may be required. To identify the localisation of gastrinoma several imaging techniques have been proposed. Somatostatin receptor scintigraphy is capable to localise the tumour in 80% of the cases and to identify it even in anatomic sites other than pancreas and duodenum. Endoscopic ultrasonography has a sensitivity as high as 79-93% and a specificity of 93%. The 2 main principal therapeutic strategies are to control both the gastric acid hypersecretion and the growth of the neoplasia. Proton pump inhibitors (PPIs) are the drugs of choice for patients with ZES. Furthermore, safety of PPIs in the maintenance therapy has been proven both in short- and in long-term studies. The best surgical treatment is excision of gastrinoma before metastatic spread has occurred. Somatostatin-analogues can reduce both gastric acid hypersecretion and serum gastrin levels. Moreover, they have an antiproliferative effect. Chemotherapy, interferon and embolisation are indicated in rapidly evolving tumours or in cases in which the tumoral symptoms cannot be treated by other approaches.

[Diagnosis and treatment of Zollinger-Ellison syndrome]

In 1970-2005 yrs. 65 patients with Zollinger-Ellison syndrome were observed and operated on in the clinic. The decisive meaning in diagnosis owes radioimmunological determination of gastrin level in the blood and its changes while conduction of tests with calcium and secretin. Surgical tactics was determined by localization, number and character of gastrinomas. During the first period of work gastrectomy with complete excision of gastrinproducing tumor constituted the operation of choice. Implementation of intraoperative method of ultrasonography have permitted to excise the benign gastrinoma when her localization was favourable with preservation of stomach. Minimal life span after gastrectomy, performed for nonresectable malignant gastrinoma, have constituted 9 years.

Surgery and prognosis of duodenal gastrinoma as a duodenal neuroendocrine tumor

It has become increasingly clear that duodenal gastrinomas are the most common cause of Zollinger-Ellison syndrome (ZES). However, attempts to find these tumors before and during surgery for ZES have had limited success until duodenotomy (opening the duodenum) was described. The routine use of duodenotomy in patients with non-familial gastrinoma increases the number of duodenal tumors found, and the immediate and long-term cure-rate. The increase in cure-rate appears to be secondary to increased detection of small, previously undetectable duodenal gastrinomas. Duodenotomy detects small tumors (<1 cm) in the proximal duodenum. It does not detect more duodenal gastrinomas per patient, nor does it detect tumors in unusual duodenal locations. Duodenotomy decreases the death-rate associated with these tumors. However, it has not affected the rate of development of liver metastases. Duodenotomy is a critical method to find duodenal gastrinomas. It should be routinely performed in all surgery to find and remove gastrinoma for cure of ZES.

[Surgical treatment of gastric, enteric, and pancreatic endocrine tumors Part 1. Treatment of primary endocrine tumors]

Endocrine tumors (ET) of the digestive tract (formerly called neuroendocrine tumors) are rare. They are classified into two principal types: gastrointestinal ET's (formerly called carcinoid tumors) which are the most common, and pancreaticoduodenal ET's. Functioning ET's secrete polypeptide hormones which cause characteristic hormonal syndromes. The management of ET is multidisciplinary. Poorly-differentiated ET's have a poor prognosis and are treated by chemotherapy. Surgical excision is the only curative treatment of well-differentiated ET's. The surgical goals are to: 1. prolong survival by resecting the primary tumor and any nodal or hepatic metastases, 2. control the symptoms related to hormonal secretion, 3. prevent or treat local complications. The most common sites of gastrointestinal ET's ( carcinoids) are the appendix and the rectum; these are often small (<1 cm), benign, and discovered fortuitously at the time of appendectomy or colonoscopic removal. Ileal ET's, even if small, are malignant, frequently multiple, and complicated in 30-50% of cases by bowel obstruction, mesenteric invasion, or bleeding. The carcinoid syndrome (consisting of abdominal pain, flushing, diarrhea, hypertension, bronchospasm, and right sided cardiac vegetations) is caused by the hypersecretion of serotonin into the systemic circulation; it occurs in 10% of cases and is usually associated with hepatic metastases. More than half of the cases of pancreatic ET are non-functional. They are usually malignant and of advanced stage at diagnosis presenting as a palpable or obstructing mass or as liver metastases. Insulinoma and gastrinoma (cause of the Zollinger-Ellison syndrome) are the most common functional ET's. 80% are sporadic; in these cases, tumor size, location, and malignant potential determine the type of resection which may vary from a simple enucleation to a formal pancreatectomy. In 10-20% of cases, pancreaticoduodenal ET presents in the setting of multiple endocrine neoplasia (NEM type I), an autosomal-dominant genetic disease with multifocal endocrine involvement of the pituitary, parathyroid, pancreas, and adrenal glands. For insulinoma with NEM-I, enucleation of lesions in the pancreatic head plus a caudal pancreatectomy is the most appropriate procedure. For gastrinoma with NEM-I, the benefit of surgical resection for tumors less than 2-3 cm in size is not clear. The lesions are frequently small, multiple, and widespread and recurrence is frequent after excision. The long-term prognosis is nevertheless fairly good. But the eventual development of liver metastases which are the most common cause of mortality still argues for an aggressive surgical approach in the early stages of the disease.

Treatment of Zollinger-Ellison Syndrome

In this article, we have reviewed the main therapeutic measures for the treatment of Zollinger-Ellison syndrome (ZES). Review of the literature was based on computer searches (Pub-Med, Index Medicus) and personal experiences. We have evaluated all the measures now available for treating patients with sporadic gastrinomas or gastrinomas associated with Multiple Endocrine Neoplasia Type 1, (MEN 1) including medical therapy such as antisecretory drugs and somatostatin analogs (SST), chemotherapy and chemoembolization, and surgical procedures. In ZES patients, the best therapeutic procedure is surgery which, if radical, can be curative. Medical treatment can be the best palliative therapy and should be used, when possible, in association with surgery, in a multimodal therapeutic approach.

[Zollinger-Ellison syndrome]

The preoperative localization of gastrinomas often fails despite all modern imaging methods. Therefore, after biochemical confirmation of the diagnosis and exclusion of diffuse metastases, a meticulous surgical exploration including intraoperative ultrasound (IOUS) and duodenal exploration after duodenotomy should be performed. The experienced surgeon will be able to identify more than 90% of the primary tumors. Depending on the localization, excision of the tumor in the duodenal wall or enucleation from the pancreatic head should be performed. If the tumor is localized in the tail of the pancreas, distal pancreatectomy is the treatment of choice. Complete resection of the tumor is the only curative approach for the patients. For MEN-1 gastrinomas a spleen-preserving distal pancreatectomy with enucleation of tumors of the pancreatic head and duodenotomy with excision of duodenal gastrinomas should be performed. If the source of gastrin secretion can be regionalized to the pancreatic head by a preoperative SASI angiography, a pylorus-preserving partial pancreaticoduodenectomy might be the treatment of choice.

Zollinger-Ellison syndrome associated with neurofibromatosis type 1: a case report

BACKGROUND

Neurofibromatosis type 1 is an autosomal dominant neurocutaneous disorder with characteristic features of skin and central nervous system involvement. Gastrointestinal involvement is rare, but the risk of malignancy development is considerable. Zollinger-Ellison syndrome is caused by gastrin-secreting tumors called gastrinomas. Correct diagnosis is often difficult, and curative treatment can only be achieved surgically.

CASE PRESENTATION

A 41-year-old female affected by neurofibromatosis type 1 presented with a history of recurrent epigastric soreness, diarrhea, and relapsing chronic duodenal ulcer. Her serum fasting gastrin level was over 1000 pg/mL. An abdominal CT scan revealed a 3 x 2-cm, well-enhanced mass adjacent to the duodenal loop. She was not associated with multiple endocrine neoplasia type 1. Operative resection was performed and gastrinoma was diagnosed by immunohistochemical staining. The serum gastrin level decreased to 99.1 pg/mL after surgery, and symptoms and endoscopic findings completely resolved without recurrences.

CONCLUSION

Gastrinoma is difficult to detect even in the general population, and hence symptoms such as recurrent idiopathic peptic ulcer and diarrhea in neurofibromatosis type 1 patients should be accounted for as possibly contributing to Zollinger-Ellison syndrome.

Zollinger-Ellison syndrome. Diagnosis and therapy

Zollinger-Ellison syndrome (ZES) is characterised by refractory peptic ulcer disease, severe diarrhoea and gastric acid hypersecretion associated with an islet-cell tumor of the pancreas (gastrinoma). ZES is sporadic in 62-80% of cases and in 20-38% of cases is associated with multiple endocrine neoplasia type 1 (MEN 1). The diagnosis of ZES is certain when the plasma gastrin is >1000 pg/mL and the basal acid output is >15 mEq/h in patients with an intact stomach, >5 mEq/h in gastrectomised patients, or when the hypergastrinemia is associated with a pH <2. Treatment is based on the control of gastric acid hypersecretion and of the malignant tumor and its possible metastases. Proton pump inhibitors are the most effective antisecretory drugs and can be administered at high dosages without drug-related adverse effects. All sporadic, localised gastrinomas should be excised if possible. When liver metastases are also present, their debulking may improve symptoms and survival, and facilitate medical treatment. There is some controversy as to the surgical approach for gastrinomas associated with MEN 1. Somatostatin analogues can be useful in reducing gastric acid hypersecretion, serum gastrin and gastric enterochromaffin-like cells, and can thus contribute to treating the disease more effectively. Their antiproliferative effect can be used in treating liver metastases. Chemotherapy and/or interferon are indicated only in patients with malignant progressive disease. Embolisation and chemoembolisation are effective in controlling clinical symptoms; however, they do not seem to improve survival.

A follow-up study of patients with Zollinger-Ellison syndrome in the period 1966-2002: effects of surgical and medical treatments on long-term survival

AIM

To evaluate the clinical history of a series of patients with Zollinger-Ellison syndrome (ZES) in the period 1966 to 2002, before and after the introduction of the current antisecretive H2 receptor antagonists and proton pump inhibitors into clinical practice.

PATIENTS AND METHODS

The study involved 18 ZES patients (9 males; mean age, 43 years; range, 12-70 years), 8 with Type 1 multiple endocrine neoplasia (MEN-1), diagnosed on the basis of standard criteria. We considered the type, number and effectiveness of surgical interventions before and after appropriate treatment, the localization of the gastrinoma, the presence of associated diseases, the causes of death, and the duration of survival.

RESULTS

Total gastrectomy (but not antrectomy and vagotomy) and full compliance to antisecretory treatment reduced the number of operations from 29 to 9. One patient was cured (5.5%), whereas relapsing gastrinomas occurred in 4 patients and associated diseases or complications in ten. Death was related to ZES in 5 patients and to other causes in 4.

CONCLUSIONS

Curing gastrinoma or appropriately inhibiting gastric acid hypersecretion in ZES patients prevent death and favors long-term survival, regardless of gastrin levels and the size or number of tumors.

Idiopathic gastric acid hypersecretion presenting as a diarrheal disorder and mimicking both Zollinger-Ellison syndrome and Crohn's disease

Many gastric acid hypersecretory states (basal acid output of greater than 15.0 mEq/h) exist for which the etiology is known, such as Zollinger-Ellison syndrome, systemic mastocytosis, antral exclusion, antral predominant Helicobacter pylori gastritis (antral G cell hyperplasia), chronic gastric outlet obstruction, short gut syndrome and basophilic leukemias. However, many hypersecretory patients have no identified etiology for their acid hypersecretion and are designated as idiopathic gastric acid hypersecretors with a basal acid output of greater than 10 mEq/h and a normal serum gastrin level. Because of the gastric acid hypersecretion these patients also commonly have an increased frequency of stools. Idiopathic gastric acid hypersecretion represents a known cause of gastric acid hypersecretion that is far more common than Zollinger-Ellison syndrome and it has a markedly different treatment regimen and natural history. We report a case of a patient with idiopathic gastric acid hypersecretion previously misdiagnosed as having Crohn's disease because of a presenting complaint of diarrhea and mimicking Zollinger-Ellison syndrome because her fasting serum gastrin level was elevated when incorrectly measured in the presence of antisecretory treatment.

Zollinger-Ellison syndrome revisited: diagnosis, biologic markers, associated inherited disorders, and acid hypersecretion

Despite general awareness of Zollinger-Ellison syndrome (ZES) by most physicians and more than 3000 articles written about it since 1955, the diagnosis of ZES is still delayed for a mean of 5 years. Recent studies show it is being delayed even more with the widespread use of proton pump inhibitors. A number of tumor markers, in addition to assessing serum gastrin, such as chromogranin A, neuron-specific enolase, and subunits of chorionic gonadotropin, have been proposed for use in either the diagnosis of pancreatic endocrine tumors, such as gastrinomas, or for assessment of tumor extent and growth. In this article important recent insights into the diagnosis of ZES as well as the clinical usefulness of assessing tumor markers for diagnosis and determination of disease extent and growth are discussed. Approximately 25% of ZES cases are due to multiple endocrine neoplasia type 1 (MEN1). A number of important studies in this group of patients are also reviewed. Finally, almost every patient with ZES has marked gastric acid hypersecretion, and its current treatment as well as the long-term possible side effects are reviewed briefly.

Resolved and unresolved controversies in the surgical management of patients with Zollinger-Ellison syndrome

OBJECTIVE

Highlight unresolved controversies in the management of Zollinger-Ellison syndrome (ZES).

SUMMARY BACKGROUND DATA

Recent studies have resolved some of the previous controversies including the surgical cure rate in patients with and without Multiple Endocrine Neoplasia-type1 (MEN1), the biological behavior of duodenal and pancreatic gastrinomas, role of imaging studies to localize tumor, and gastrectomy to manage acid output.

METHODS

Review of the literature based on computer searches in Index Medicus, Pubmed and Ovid.

RESULTS

Current controversies as identified in the literature include the role of endoscopic ultrasound (EUS), surgery in ZES patients with MEN1, pancreaticoduodenectomy (Whipple procedure), lymph node primary gastrinoma, parietal cell vagotomy, reoperation and surgery for metastatic tumor, and the use of minimally invasive surgical techniques to localize and remove gastrinoma.

CONCLUSIONS

It is hoped that future studies will focus on these issues to improve the surgical management of ZES patients.

Endocrine tumors of the duodenum. A study of 55 cases relative to clinicopathological features and hormone content

BACKGROUND/AIMS

Study of prognosis of duodenal endocrine tumors.

METHODOLOGY

Retrospective study concerned 55 duodenal endocrine tumors discovered in biopsy or surgical specimens. Follow-up records available for 49 patients indicated that inconspicuous associated clinical manifestations were often found subsequently. Seven patients were classified as Zollinger-Ellison syndrome and seven as multiple endocrine neoplasia (6 MEN I and 1 MEN II).

RESULTS

Tumors were small (mean 1.28cm) and located preferentially in the first and second part of the duodenum. Fifty-four were well-differentiated and one poorly differentiated. Immunochemistry revealed 30 G-cell tumors (54.6%), 15 D-cell (27.3%), two plurihormonal (EC cell and G cell), and one GRH-cell, whereas seven could not be classified. Fifteen patients died (five in relation to their disease). Twenty-one had metastases (liver, nodes, lung), eight of whom are still alive.

CONCLUSIONS

Eighty-eight percent of duodenal endocrine tumors were gastrinomas, small plurifocal tumors and somatostatinomas preferentially located in the ampullar region and diagnosed because of hematemesis or icterus. Size is an important prognostic factor in determining whether surgery is required. The prognosis is better for D- and G-cell tumors than pancreatic endocrine tumors. Duodenal endocrine tumors in multiple endocrine neoplasia have a good prognosis, but can be associated with pancreatic plurihormonal tumors and metastases.