Spectrum of malignant somatostatin-producing neuroendocrine tumors.

OBJECTIVE: To evaluate the clinical manifestations and outcome of patients with somatostatinomas--rare neuroendocrine tumors of pancreaticoduodenal origin. METHODS: We searched the medical archives and tumor registry of our institution for somatostatinomas or somatostatin-staining tumors for the 12-year period from January 1990 to February 2002. In addition, we reviewed laboratory databases for patients who had an elevated serum somatostatin level. Patients with a neuroendocrine tumor and an elevated serum somatostatin level or somatostatin-positive tumor immunostaining were included in this study. RESULTS: Eleven patients qualified (9 men and 2 women; median age at diagnosis, 45 years; age range, 22 to 73). The diagnosis of a somatostatinoma was made by immunostaining of the tumor in 9 patients and by finding elevated serum somatostatin levels in 2. Five primary tumors were of duodenal and 6 of pancreatic origin. Psammoma body formation and association with neurofibromatosis were seen only in the duodenal tumors. The known primary tumor sizes varied from 2 to 6 cm. Liver metastatic lesions were present in 6 patients, abdominal lymph node involvement was found in 10 patients, and lung, spleen, and ovarian metastatic involvement was noted in 1 patient each. Diabetes was present in 4 patients (36%) and cholelithiasis in 7 (64%). The presence of a mass led to the diagnosis in most patients with primary duodenal tumors, whereas patients with pancreatic tumors were more likely to have endocrine manifestations. A Whipple procedure was performed in 6 patients, distal pancreatectomy in 3, hepatic artery embolization or ligation in 3, and partial hepatectomy in 1. Cancer-related death occurred in 4 patients, 1 to 8 years after diagnosis (median, 4.5 years). At last follow-up, 2 patients were alive without evidence of disease (8 and 10 years after diagnosis), and 3 were alive with liver metastatic lesions. The status of 2 patients was unclear. CONCLUSION: Somatostatinomas occurred with approximately equal frequency in the duodenum and the pancreas. The duodenal tumors were more likely to be pure somatostatinomas and have psammoma bodies. Pancreatic tumors were more likely to be multihormonal. Cholelithiasis and diabetes were seen in 64% and 36%, respectively, of the patients. Mass effect of the tumor was the usual manifestation leading to diagnosis. These tumors are slow growing, and long-term survival is possible.

Duodenal neuroendocrine tumors: Classification, functional syndromes, diagnosis and medical treatment.

Duodenal neuroendocrine tumors (NETs) comprise 2-3% of all GI endocrine tumors and are increasing in frequency. These include gastrinomas, somatostatinomas, nonfunctional NETs, gangliocytic paragangliomas, and poorly differentiated NE carcinomas. Although, the majority are nonfunctional, these tumors are a frequent cause of Zollinger-Ellison syndrome and can cause other clinical hormonal syndromes (carcinoid, Cushing's, etc.). In this chapter, their epidemiology, clinical aspects, localization, diagnosis and medical treatment are reviewed including the latest advances in each area.

Endocrine tumours of the pancreas.

Endocrine pancreatic tumours (EPTs) are uncommon tumours occurring in approximately 1 in 100,000 of the population, representing 1-2% of all pancreatic neoplasms. Some of the tumours may be part of multiple endocrine neoplasia type one (MEN-1) syndrome or von Hippel-Lindau (vHL) disease. EPTs are classified as functioning or non-functioning tumours on the basis of their clinical manifestation. The biochemical diagnosis of EPT is based on hormones and amines released. Besides specific markers such as insulin, there are also general tumour markers such as chromogranin A, which is the most valuable marker and has been reported to be increased in plasma in 50-80% of patients with EPTs and correlates with tumour burden. The location of endocrine tumours of the pancreas includes different techniques, from endoscopic investigations to scintigraphy (e.g. somatostatin receptor scintigraphy) and positron emission tomography. The medical treatment of endocrine pancreatic tumours consists of chemotherapy, somatostatin analogues and alpha-interferon. None of these can cure a patient with malignant disease. In future, therapy will be custom-made and based on current knowledge of tumour biology and molecular genetics.

Rare endocrine tumours of the GI tract.

Functional pancreatic endocrine tumors other than gastrinoma and insulinoma are quite rare. The principles of management include the diagnosis and management of the functional hormonal syndrome, and management of the potentially malignant tumor. Optimally, control of the hormonal syndrome is achieved preoperatively to stabilize the patient status for the operation, however, resection may be an important part of the control of the hormonal syndrome. Ultimately, the only curative treatment for these neoplasms is complete tumour resection, when feasible.

Prevalence, characteristics and prognosis of MEN 1-associated glucagonomas, VIPomas, and somatostatinomas: study from the GTE (Groupe des Tumeurs Endocrines) registry.

UNLABELLED: Few studies have concerned the rare functioning endocrine pancreatic tumors associated with multiple endocrine neoplasia type 1 (MEN 1). When sporadic, these tumors have a poor prognosis. AIM: To analyze the frequency, characteristics and prognosis of MEN 1-associated glucagonomas, VIPomas and somatostatinomas recorded in the GTE (Groupe des Tumeurs Endocrines) registry. METHODS: Records of the patients whose GTE registry codes included glucagonoma, VIPoma or somatostatinoma were reviewed. The diagnosis was confirmed when there were clinical signs of a functioning tumor and/or when blood levels of the peptide were higher than twice the upper limit of normal. RESULTS: Among 580 patients with MEN 1, duodeno-pancreatic involvement was present in 307 (52.9%). Five (1.6%) had a glucagonoma, 3 (0.98%) a VIPoma and 2 (0.65%) a somatostatinoma. A clinical syndrome was present in 1 patient with glucagonoma, in the 3 with VIPomas and in 1 with somatostatinoma. Tumor size was greater than 3 cm more often for these rare tumours (67%) than in patients with other type of duodeno-pancreatic involvement (28%) (P=0.02) and visceral metastases were more frequent (40% vs 15%; P=0.056). Ten-year survival of patients with glucagonomas, VIPomas or somatostatinomas (53.8%; CI95%: 15.5-92.1) was poorer than that of patients with insulinomas (91.4%; CI95%: 83.399.5; P=0.01) or gastrinomas (81.7%; CI95%: 74.9-88.5; P=0.20) and close to that of patients with non-functioning tumors (62.2%, CI95%: 41.0-83.9; NS). CONCLUSION: Glucagonomas, VIPomas and somatostatinomas, especially the functioning type, are very rare in patients with MEN 1. Prognosis is poor, probably because of large tumor size and high rate of metastasis. Survival is similar to that in patients with non-functioning tumors.

Malignant duodenal somatostatinoma presenting in association with von Recklinghausen disease.

Somatostatinomas are extremely rare periampullary malignant neuroendocrine tumors that may be associated with von Recklinghausen disease or type-I neurofibromatosis. Duodenal somatostatinomas are distinguished from pancreatic somatostatinomas by their frequent association with type-I neurofibromatosis and typically absence of somatostatinoma syndrome. We report a very rare and atypical case of malignant duodenal somatostatinoma presenting with somatostatinoma syndrome in association with type-I neurofibromatosis.

Carcinoid somatostatinoma of the papilla of Vater: a case report.

A 57 year-old Japanese man with a carcinoid somatostatinoma of the papilla of Vater is presented. He was found to have cholecystolithiasis without any symptoms. Physical examination showed no abnormal findings. Routine laboratory data gave normal results, except for glucose intolerance and an elevated somatostatin concentration. A yellowish papillary tumor was found at the papilla of Vater, and histological examination suggested the diagnosis of carcinoid. He underwent a pancreatoduodenectomy in March 1992. The gallbladder contained a single pure cholesterol stone. Histological, immunohistochemical, and electron microscopic studies resulted in the diagnosis of a carcinoid somatostatinoma of the papilla of Vater, without regional lymph node metastases. Post-operative pancreatic juice output from the total pancreatic duct drainage increased to more than 1000 mL/day. Although an anastomotic leakage of the pancreatojejunostomy was noted, the pancreatic fistula closed 8 weeks later. His postoperative somatostatin value was normal. He has been well for 54 months following surgery, without any signs of recurrence.