Novel insights into the polycythemia-paraganglioma-somatostatinoma syndrome

Worldwide, the syndromes of paraganglioma (PGL), somatostatinoma (SOM) and early childhood polycythemia are described in only a few patients with somatic mutations in the hypoxia-inducible factor 2 alpha (HIF2A). This study provides detailed information about the clinical aspects and course of 7 patients with this syndrome and brings into perspective these experiences with the pertinent literature. Six females and one male presented at a median age of 28 years (range 11-46). Two were found to have HIF2A somatic mosaicism. No relatives were affected. All patients were diagnosed with polycythemia before age 8 and before PGL/SOM developed. PGLs were found at a median age of 17 years (range 8-38) and SOMs at 29 years (range 22-38). PGLs were multiple, recurrent and metastatic in 100, 100 and 29% of all cases, and SOMs in 40, 40 and 60%, respectively. All PGLs were primarily norepinephrine-producing. All patients had abnormal ophthalmologic findings and those with SOMs had gallbladder disease. Computed tomography (CT) and magnetic resonance imaging revealed cystic lesions at multiple sites and hemangiomas in 4 patients (57%), previously thought to be pathognomonic for von Hippel-Lindau disease. The most accurate radiopharmaceutical to detect PGL appeared to be [¹⁸F]-fluorodihydroxyphenylalanine ([¹⁸F]-FDOPA). Therefore, [¹⁸F]-FDOPA PET/CT, not [⁶⁸Ga]-(DOTA)-[Tyr3]-octreotate ([⁶⁸Ga]-DOTATATE) PET/CT is recommended for tumor localization and aftercare in this syndrome. The long-term prognosis of the syndrome is unknown. However, to date no deaths occurred after 6 years follow-up. Physicians should be aware of this unique syndrome and its diagnostic and therapeutic challenges.

Case report: recurrent acute pancreatitis secondary to papillary somatostatinoma--a new association

Acute pancreatitis may rarely be caused by papillary mass lesions such as adenocarcinomas and neuroendocrine tumours. Occasionally these papillary lesions may cause recurrent episodes of acute pancreatitis and patients presenting in this way require further pancreatic investigation. We believe this to be the first reported case of a duodenal papillary somatostatinoma causing recurrent acute pancreatitis. The patient was investigated with multiple imaging modalities, both at endoscopy and with more traditional radiology, and treated with resection by Whipple's pancreaticoduodenectomy. If diagnosed early in the absence of distant metastases the prognosis of papillary somatostatinoma with tumour resection is excellent.

Severely fluctuating blood glucose levels associated with a somatostatin-producing ovarian neuroendocrine tumor

CONTEXT

Somatostatin-producing tumors are a rare type of neuroendocrine tumor. Their effects on blood glucose levels have been variously reported, and detailed reports have been scarce.

OBJECTIVE

The aim of this study was to identify the reasons for the extraordinary blood glucose fluctuations in a case with no previous history of diabetes.

PATIENTS AND METHODS

A 68-yr-old nondiabetic woman with an ovarian tumor was suffering from hyper- and hypoglycemia. Based on the results of an oral glucose tolerance test and continuous glucose monitoring, we speculated that the fluctuating blood glucose level was accompanied not only by a low insulin level but also by low counter-regulatory hormones levels, and that those broad hormonal suppressions were caused by a high somatostatin level produced in the ovarian tumor. We performed an oophorectomy and assessed the pathology of the tumor and changes in the blood glucose profile as well as hormonal levels postoperatively.

RESULTS

The blood glucose level was completely normalized after the oophorectomy. Insulin secretion was also normalized. Histological examination showed that the tumor comprised a mature cystic teratoma and a stromal carcinoid. Immunohistochemically, the stromal carcinoid component was positive for somatostatin. The somatostatin level was 8505 pmol/liter preoperatively, which dropped down to 71.5 pmol/liter postoperatively. We found two previous reports of somatostatin-producing ovarian neuroendocrine tumors. Somatostatin levels among cases of ovarian origin were much higher than those among cases of gastrointestinal origins, and cases of ovarian origin all experienced blood glucose fluctuations.

CONCLUSION

Extremely high somatostatin levels and blood glucose fluctuations may be characteristics of somatostatin-producing ovarian neuroendocrine tumors.

Somatic HIF2A gain-of-function mutations in paraganglioma with polycythemia

Hypoxia-inducible factors are transcription factors controlling energy, iron metabolism, erythropoiesis, and development. When these proteins are dysregulated, they contribute to tumorigenesis and cancer progression. However, mutations in genes encoding α subunits of hypoxia-inducible factors (HIF-α) have not previously been identified in any cancer. Here we report two novel somatic gain-of-function mutations in the gene encoding hypoxia-inducible factor 2α (HIF2A) in two patients, one presenting with paraganglioma and the other with paraganglioma and somatostatinoma, both of whom had polycythemia. The two mutations were associated with increased HIF-2α activity and increased protein half-life.

A rare cause of obstructive jaundice and weight loss in Von Recklinghausen's disease

We present the case of a patient with the rare triad of Von Recklinghausen's disease associated with a somatostatinoma and a gastrointestinal stromal tumour (GIST). The patient had recurrent jaundice, the typical somatostatinoma syndrome, positive MR imaging but negative ⁶⁸Ga-DOTATOC PET scanning in a histopathology-proven somatostatinoma tumour.

Pancreatic somatostatinoma manifested as severe hypoglycemia

Somatostatinoma is a rare somatostatin-producing endocrine tumor, probably malignant. Due to its nonspecific symptoms such as vague abdominal pain, weight loss, or occult clinical features, misdiagnosis occurs. We report a case of pancreatic somatostatinoma with severe hypoglycemia. The patient had experienced severe hypoglycemic attacks for 11 months periodically. Contrast computed tomography scan revealed an isodensity mass about 2 cm in the head of the pancreas. Ultimately, a local excision was carried out as the tumor was located exactly on the surface of the pancreas. Somatostatinoma was established after immunohistochemical technique. The patient led a normal life without any complaint at 1 year follow-up.

Large somatostatin-producing endocrine carcinoma of the ampulla of vater in association with GIST in a patient with von Recklinghausen's disease. Case report and review of the literature

CONTEXT

Somatostatin-producing endocrine tumors of the duodenum are very rare neoplasms of the gastrointestinal tract. These tumors may be associated with von Recklinghausen's disease.

CASE REPORT

We present the case of a 49-year-old female patient with von Recklinghausen's disease and an incidentally diagnosed ampullary neoplasm. The patient was treated with a classical pancreaticoduodenectomy. At surgery, a mass was found in the greater curve of the stomach which was resected using the classic Whipple procedure. Histology and immunohistochemistry showed that the duodenal tumor was an ampullary somatostatin-producing endocrine carcinoma while the gastric tumor was a gastrointestinal stromal tumor (GIST). The postoperative course was uneventful and the patient is alive, without tumor recurrence, six years after surgery.

CONCLUSION

Somatostatin-producing endocrine tumors of the duodenum are rare tumors, often associated with von Recklinghausen's disease; these neoplasms should be treated aggressively using radical surgical resection. Although local resection may be appropriate for small duodenal somatostatin-producing tumors, a pancreaticoduodenectomy is usually required for larger tumors.

[Somatostatinoma of the Vater's papilla in a patient with von Recklinghausen's disease]

BACKGROUND

Somatostatinomas of the gastrointestinal tract secret hormon somatostatin which can cause "inhibitory syndrom" comprising diabetes mellitus, cholelithiasis and steatorrheic diarrhea. It is also secreted by the D cells of Langerhans's islands of the pancreas as well as endocrine cells of the stomack, small bowel, salivary glands and parafollicular cells of the thiroid gland. Somatostatinomas of the digestive tract appear within the pancreas and duodenum. Patients suffering from von Recklinghausens's disease are paticularly prone to the somatostatinomas of the duodenum.

CASE REPORT

In this paper we presented a 51-year-old female patient with von Recklinghausen's disease in whom, during the investigation for obstructive jaundice, tumor of the Vater's papilla was found. The patient was submitted to Whipple's duodenopancreatectomy. Histology and immunohistochemistry discovered type B glandular carcinoid tumor with strong antisomatostatin and mild antigastrin immunoreactivity. The patient stayed symptom-free more than four years now.

CONCLUSION

Patients with von Recklinghausen's disease should be examined for other tumors, particularly carcinoids of the duodenum and papilla, especially if the signs of cholestasis are present.

[Type I neurofibromatosis, pheochromocytoma and somatostatinoma of the ampulla. Literature review]

Gastrointestinal involvement in Von Recklinghausen's neurofibromatosis (autosomal dominant disease) is observed in 25% of patients and is frequently represented by duodenal carcinoids. We report a case of somatostatinoma of the ampulla in a 42-year-old female with neurofibromatosis and pheochromocytoma and show a literature review about the association of neurofibromatosis and somatostatinoma. This pathological association appears non hasardous and surgical ampullectomy offers a good alternative to pancreaticoduodenectomy in localised tumors treatment.

Duodenal somatostatinoma associated with Von Recklinghausen's disease

Somatostatinomas are rare, malignant, somatostatin-producing neuroendocrine tumors with a prevalence of one in 40 million. The coincidence of Von Recklinghausen's disease and duodenal somatostatinoma has been known since 1982. We report the case of a 57-year-old female patient with Von Recklinghausen's disease and a tumor of the pancreatic head that was diagnosed due to painless icterus. Histopathological examination after pylorus-preserving pancreatoduodenectomy revealed the existence of a duodenal somatostatinoma with lymph node metastases. Characteristics of the association of von Recklinghausen's disease and somatostatinoma, and therapy and prognosis will be discussed. In patients with Von Recklinghausen's disease and an ampullary tumor, a somatostatinoma should be considered. In contrast to its pancreatic counterparts, duodenal somatostatinoma is frequently associated with Von Recklinghausen's disease, often contains psammoma bodies, is rarely associated with a recognizable "somatostatin syndrome", and is hardly ever associated with demonstrable metastases at the time of diagnosis. Small tumors arising in the duodenum may be treated with local excision, whereas larger tumors should be treated by total excision, which may entail a partial pancreatoduodenectomy.

Large duodenal somatostatinoma in the third portion associated with severe glucose intolerance

A 51-year-old man was admitted with hyperglycemia and a duodenal tumor. Although his glycemic control was poor, basal C-peptide levels were not suppressed. Further examination revealed a mass measuring 7.8 cm in diameter in the third portion of the duodenum. Duodenectomy revealed a slow-growing sessile tumor located near Treitz's ligament. The immunohistochemical profile of sections of the specimen revealed the presence of somatostatin. The patient's serum somatostatin was elevated to 300 pg/ml preoperatively, but was reduced to 10 pg/ml postoperatively. Glycemic control also normalized after the operation.

Von Recklinghausen's neurofibromatosis associated with duodenal somatostatinoma. A case report and review of the literature

Somatostatin producing duodenal carcinoids are rare, comprising a mere 2% of small bowel carcinoids and 5-10% of all duodenal tumors. Since the 1st case described by Kaneko in 1979 more than 50 cases have been reported in the world literature. From these reports, it is gradually emerging that duodenal somatostatinomas may show a strong association with von Recklinhausen's neurofibromatosis (VRNF) as a distinct neuroendocrine syndrome. A case of a patient affected by VRNF associated with duodenal somatostatinoma with consequent obstructive jaundice is reported. The authors discuss the characteristics of these tumors and review the literature. A total of 27 patients with Von Recklinghausen's disease associated with immunohistologically proved duodenal somatostatinoma have been identified and compared with 29 duodenal somatostatinoma not associated with VRNF, and with 32 cases of pancreatic somatostatinomas.

Somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease

We report a case of somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease (VRD). A 64-year-old woman who had had recurrent attacks of acute pancreatitis and cholangitis was found, on gastroduodenal endoscopy, to have a tumor of the papilla of Vater and multiple submucosal tumors of the stomach and duodenum. Numerous submucosal tumors were observed in the stomach, duodenum, and jejunum, and total excision of the papilla of Vater and resection of the duodenal and jejunal submucosal tumors was performed. The tumor of the papilla of Vater showed the histologic appearance of a dense proliferation of tumor cells in acinar form, from the duodenal mucosa to the muscle layer, and psammoma bodies were revealed within the tumor. Immunohistologically, the tumor cells were intensely positive for somatostatin. The submucosal tumors of the duodenum and jejunum were negative for smooth muscle actin, s-100, and neuron-specific enolase (NSE), and positive for CD34 and c-kit, and they were diagnosed as gastrointestinal stromal tumors (GISTs) according to the strict definition. The only 25 cases of papilla of Vater somatostatinoma associated with VRD to have been reported in the English-language literature since 1982 are reviewed, as well as our own case.

[Von Recklinghausen's disease associated with pancreatic somatostatinoma]

INTRODUCTION

Pancreatic somatostatinoma is a rare entity and its association with Von Recklinghausen's disease has only been described on two occasions. We report a new observation, with clinical and evolving status differing from those described in isolated cases of somatostatinoma.

OBSERVATION

A 28 year-old man presenting with familial Von Recklinghausen's disease, had suffered for 10 years from paroxysmic abdominal pain. He was hospitalized for intense pain. Imaging revealed a retroperineal tumoral formation. Following duodenopancreatectomy, somatostatinoma was diagnosed. Diffuse metastatic miliary was revealed and multiple glandular metastases.

DISCUSSION

Other than the rarity of the morbid association (pancreatic somatostatinoma and Von Recklinghausen's disease) described, this case is particular in that the patient was very young, symptomatology was unapparent and tumoral evolution was minimal.

Duodenal somatostatinoma presenting with complete somatostatinoma syndrome

Somatostatinomas are the rarest pancreatic endocrine tumors and can arise in the pancreas or duodenum. Duodenal somatostatinomas are less common than, and are distinguished from, their pancreatic counterparts by a frequent association with type I neurofibromatosis, the presence of psammoma bodies, the less frequent presence of metastatic disease, and the absence of somatostatinoma syndrome (diabetes mellitus, steatorrhea, and cholelithiasis). We report a case of somatostatinoma with metastases and psammoma bodies presenting with all three features of the syndrome in a patient with neurofibromatosis. Although several reports have documented portions of the syndrome in patients with duodenal somatostatinomas, to our knowledge, this is the first report of the complete syndrome associated with a duodenal lesion.

[Duodenal somatostatinoma. Anatomic/clinical study of 12 operated cases]

STUDY AIM

Duodenal somatostatinomas (DS) are very rare neuro-endocrine tumours. The aim of this retrospective and multicentric study was to report the clinical and pathological characteristics of these neoplasms in a series of 12 patients and to compare them with the literature.

PATIENTS AND METHODS

From 1987 to 1998, 12 patients were operated for a DS. There were seven women and five men ranging in age from 23 to 72 years (mean age: 56.6 years). Four patients had an associated von Recklinghausen's disease, one of them with multiple endocrine neoplasia (MEN type IIa) and medullary carcinoma of the thyroíd. The surgical procedures were pancreaticoduodenectomy (n = 8), small bowel resection (n = 2), inferior gastrectomy (n = 1) and gastrojejunostomy with hepatic metastases biopsies (n = 1). The tumour was mainly located on the 2nd duodenum (n = 10), with a mean size of 2.7 cm (ranging from 0.4 to 6 cm) and with a pancreatic invasion in three patients. A metastatic disease was present at the time of diagnosis in eight patients. There were, according to Capella's classification, two patients in the groups I and II, and ten patients in group III (83%), respectively.

RESULTS

There was one postoperative death after a pancreaticoduodenectomy. Three patients secondarily died from tumoral progression. Eight patients were alive, with a mean follow-up of 84 months (ranging from 5 to 290 months), at the end-point of the study.

CONCLUSION

Duodenal somatostatinomas are rare neuroendocrine, generally non-functioning, well-differentiated tumours with a low grade of malignancy. The association with the von Recklinghausen's disease is frequent. The clinical somatostatinoma syndrome with diabetes, diarrhea and biliary lithiasis is rare. The treatment is surgical even with a metastatic disease. The 5-year survival rate is better than those of the pancreatic somatostatinomas or the duodenal gastrinomas.

[Duodenal somatostatinomas associated with von Recklinghausen's neurofibromatosis. Apropos of 2 cases]

Somatostatinomas are rare neuroendocrine tumors; they are essentially located in the pancreas and in the duodenum. The association with a neurofibromatosis type I is especially observed when the tumor is located in the ampulla of Vater. These tumors are not associated with a "somatostatin syndrome", but often present with gastrointestinal bleeding, abdominal pain and obstructive jaundice. The diagnosis is confirmed by immunohistochemical studies. The aim of this study is to report 2 cases of metastazing duodenal periampullary somatostatinomas associated with von Recklinghausen's disease and to discuss the prognosis of these tumors. Future genetic research are necessary as point out the familial feature of this association in one of our cases.

[Glucagonoma--somatostatinoma]

Glucagonoma and somatostatinoma are tumors which produce the respective hormone. When these peptides are also secreted into the circulation the clinical syndromes are characterized by the signs and symptoms due to hormone overproduction. In case of the glucagonoma-syndrome diabetes and typical skin lesions are dominating while patients with the somatostatinoma syndrome have diabetes frequently associated with steatorrhea. Surgical resection of the tumor and its metastases as far as possible is the therapy of choice. For symptomatic relief and inhibition of the growth of the metastases interferon-a and somatostatin analogues can be employed.

Duodenal somatostatinoma presenting as upper gastrointestinal bleeding

Duodenal somatostatinoma is a rare cause of upper gastrointestinal bleeding. We report the case of a 55-yr-old woman who presented with upper gastrointestinal hemorrhage due to a duodenal somatostatinoma. We discuss the characteristics of these tumors, and review the literature on diagnostic workup and management.

Heterotopic pancreas, periampullary somatostatinoma and type I neurofibromatosis: a pathogenetic proposal

This case documents the association of ectopic pancreatic tissue with a duodenal somatostatinoma in a patient with type I neurofibromatosis. Pancreatic ducts have been noted within the centres of somatostatinomas, but little significance has been attached to this finding. Here we describe a patient in whom a separate proliferation of somatostatin cells occurred in association with the ectopic pancreatic ductular epithelium. This lesion bore a striking resemblance to the ductulo-insular or ductulo-endocrine complexes that are seen in nesidioblastosis in the pancreas. We therefore postulate that the ducts, which are sequestered within somatostatinomas, are of pathogenetic significance. The somatostatin-producing cells arise from these ducts, very much in the fashion of ductulo-endocrine complexes in nesidioblastosis.

[Duodenal somatostatinomas associated with von Recklinghausen disease]

A case of von Recklinghausen's disease with double somatostatin producing neuroendocrine tumour of the ampulla and duodenum is reported. A search of the world's literature revealed 28 patients with immunohistologically proven duodenal somatostatinoma associated with type I neurofibromatosis. These tumours are seldom associated with a recognizable "somatostatin syndrome", but often present with obstructive jaundice, duodenal obstruction, weight loss or gastrointestinal bleeding. Histologically, psammoma bodies are frequently encountered in the glandular lumina of duodenal somatostatinomas (66%), whereas their presence in other neuroendocrine tumours of the gastrointestinal tract is very rare. Metastatization is rare (27%) and mainly confined to lymph nodes (88%). In the world literature duodenal somatostatinoma is associated with von Recklinghausen's disease in 50%.

[Duodenal somatostatinoma associated with von Recklinghausen's neurofibromatosis]

This case report describes a 27-year-old man with von Recklinghausen's neurofibromatosis, manifested as cutaneous cafè au lait spots and neurofibromas, associated with duodenal somatostatinoma. The patient presented with ultrasonographic evidence of dilatation of the biliary and pancreatic ducts, in absence of clinical symptoms. The reason for the performance of ultrasonography was to identify the cause of an increase of hepatic enzymes during the last two years. Diagnostic ERCP showed an ulcerated tumor in the papillary region and pathological findings were compatible with somatostatinoma. Endoscopic sphincterotomy with placement of endoprostheses was successful in achieving biliary and pancreatic drainage. Subsequently a curative resection of the tumor was performed by the Whipple procedure and provocative tests demonstrated normal plasma somatostatin concentrations.

Ampullary somatostatinoma in a patient with von Recklinghausen's disease

We report a case of somatostatinoma of the ampulla of Vater associated with von Recklinghausen's disease in a 44-year-old woman. On admission the patient was jaundiced, and percutaneous Cholangio-drainage was performed. Cholangiography revealed stenosis of the common bile duct at the lower end Duodenoscopy showed a yellowish tumor of the ampulla of Vater, and the biopsy specimens showed no malignant cells. Pylorus-preserving pancreaticoduo-denectomy was performed. Histologically, the tumor was composed of small round cells with a solid or trabecular pattern and with multiple psammoma bodies. Immunohistochemical examination showed that the tumor cells stained for somatostatin. Genomic examination showed neither K-ras nor p53 gene mutations of the resected specimen.

Ampullary somatostatinoma associated with von Recklinghausen's neurofibromatosis presenting as obstructive jaundice

A case of von Recklinghausen's disease associated with a somatostatinoma of the pancreas causing obstructive jaundice is described. Discussion on the association of von Recklinghausen's disease with somatostatinoma is presented.

Carcinoid syndrome due to a malignant somatostatinoma

Somatostatinoma is one of the rarest tumours of the endocrine pancreas. Cardinal manifestations of a somatostatinoma include gallstones, mild diabetes mellitus, steatorrhoea, diarrhoea and dyspepsia. Like any other pancreatic islet cell carcinoma, a somatostatinoma may also produce several different hormones such as adrenocorticotropic hormone, calcitonin, vasoactive intestinal polypeptide, pancreatic polypeptide, gastrin, insulin, and glucagon. In many cases, the clinical picture is dominated by the effect of these other hormones. We present a patient with somatostatinoma in which an immunocytochemical study of the specimens from pancreas and liver showed a weak positive reaction for gastrin besides a strong positive reaction for somatostatin. Interestingly, this patient also showed the signs of carcinoid syndrome which was successfully treated with octreotide.

Somatostatinoma of the pancreas associated with von Hippel-Lindau disease

A 39-year-old man was admitted because of lumbago, vomiting and massive gastrointestinal bleeding. Oliguria developed a few days later, which was followed by hyperkalemia and cardiac arrest. Autopsy disclosed multiple renal cell carcinomas with diffuse metastasis to the liver, adrenal gland, psoas muscle and vertebrae. In addition, a somatostatinoma was found in the pancreas. From these findings and past history of cerebellar hemangioblastoma and spinal hemangioma he was diagnosed to have von Hippel-Lindau disease. Von Hippel-Lindau disease with islet cell tumor is very rare and is reported here with a review of literature.

Von Recklinghausen's disease associated with duodenal somatostatinoma: contrast of duodenal versus pancreatic somatostatinomas

A case of Von Recklinghausen's disease with duodenal somatostatinoma is reported. A search of the world's literature revealed 27 patients with Von Recklinghausen's disease associated with an immunohistologically proved duodenal somatostatinoma. Twenty-nine cases of duodenal somatostatinoma not associated with Von Recklinghausen's disease and 32 cases of pancreatic somatostatinomas have been identified for comparison. While their histology may be similar in many respects, the duodenal and pancreatic somatostatinomas show significant differences, especially in hormonal and growth behaviors. In contrast to its pancreatic counterpart, the duodenal somatostatinoma is frequently associated with Von Recklinghausen's disease, is seldom associated with a recognizable "somatostatin syndrome," often contains psammoma bodies, and is less frequently associated with demonstrable metastases at the time of operation.

Somatostatinoma of the pancreas with hypercalcaemia. A case report

A unique case of somatostatinoma of the pancreas complicated by severe hypercalcaemia is described. Surgical resection was not possible owing to tumour extent. A dramatic and prolonged clinical and biochemical response was achieved with streptozotocin.

Exocrine pancreatic insufficiency and pancreatic fibrosis due to duodenal somatostatinoma in a patient with neurofibromatosis

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).

von Recklinghausen's disease associated with somatostatin-rich duodenal carcinoid (somatostatinoma), medullary thyroid carcinoma and diffuse adrenal medullary hyperplasia

This report describes the concomitant occurrence of a somatostatin-rich duodenal carcinoid, a medullary thyroid carcinoma and a diffuse adrenal medullary hyperplasia in a patient with von Recklinghausen's disease. A 50-year-old Japanese man died from lung metastasis of a malignant schwannoma. In addition to extensive viscero-cutaneous neurofibromatosis, two different types of neuroendocrine tumors were found in the duodenum and thyroid gland at autopsy. The duodenal tumor, which was located in the second portion, showed the histologic appearance of a carcinoid tumor with glandular differentiation and psammoma-bodies. Immunohistochemically the tumor cells were intensely positive for somatostatin. The thyroid tumor was composed of nests of tumor cells arranged in an endocrine pattern, and showed immunoreactivity for calcitonin. A review of the literature revealed no previously reported case of concomitant occurrence of duodenal somatostatinoma and medullary thyroid carcinoma in a single patient with von Recklinghausen's disease. Morphometric analysis of adrenal glands disclosed the presence of diffuse medullary hyperplasia. Thus, the present case exhibited a similarity in some respects with multiple endocrine neoplasia (MEN) syndrome, Type IIa or IIb.

Duodenal somatostatinoma with congenital pseudoarthrosis

We describe a previously unreported association between somatostatinoma and congenital pseudoarthrosis. Because pseudoarthrosis is part of von Recklinghausen's disease, in turn with an association with somatostatinoma, we speculate on a link between pseudoarthrosis and somatostatinoma.

Duodenal carcinoid (somatostatinoma) combined with von Recklinghausen's disease. A case report and review of the literature

We report the immunohistochemical and ultrastructural features of a case of duodenal carcinoid (somatostatinoma) combined with cutaneous-type von Recklinghausen's disease in a 65-year-old woman. The duodenal tumor located at the 2nd portion was composed of tumor cells arranged in a trabecular, glandular or nest-like pattern, occasionally associated with eosinophilic globules in the glandular structures. The tumor cells mostly showed strong immunoreactivity with anti-somatostatin antibody. Electron microscopy revealed that every tumor cell contained intracytoplasmic granules with electron-dense cores, 100-300 nm in size, in varying numbers, and intracytoplasmic lumina were rarely detected. The present case including identical cases reported so far suggest that the disease entity is likely to be a combination of duodenal somatostatinoma and von Recklinghausen's disease and/or phaeochromocytoma. This is the tenth case of duodenal carcinoid associated with von Recklinghausen's disease and/or phaeochromocytoma in the world literature and the third case reported as duodenal somatostatinoma.

Pancreatic somatostatinoma: presentation with recurrent episodes of severe hyperglycaemia and ketoacidosis

A 47-year-old woman was admitted on four occasions over a four-year period with severe hyperglycaemia associated with marked ketoacidosis. She had weight loss with hepatomegaly and ultrasonography indicated a pancreatic tumour which was shown to be a somatostatinoma. Resection resulted in prolonged survival. The biochemical and morphological features of this rare tumour are presented, and an explanation for the unusual presentation of a somatostatinoma with episodes of ketoacidosis is given.

Malignant pancreatic somatostatinoma in a patient with dermatitis herpetiformis and coeliac disease

A case of malignant somatostatinoma is reported in a patient with long-standing dermatitis herpetiformis and coeliac disease. The patient had non-specific abdominal pain of several years duration and came to attention because of weight loss despite strict adherence to a gluten-free diet. Plasma somatostatin levels were raised, and laparotomy showed a pancreatic tumour with metastases, which on histology, electron microscopy and immunohistochemistry proved to be a somatostatinoma. After a promising initial response to streptozotocin, she died 30 months later. This is the first reported occurrence of a somatostatinoma in a patient with coeliac disease, adding to the growing list of neoplastic complications in this condition.

Clinical and pathophysiological aspects of somatostatin and the gastrointestinal tract

Somatostatin is present in the gastrointestinal tract in appreciable amounts. The highest concentrations of the polypeptide are found in the stomach, the upper small intestine, and the pancreas. Within the gastrointestinal tract, somatostatin inhibits various functions, including endocrine and exocrine secretion, motility, blood flow, absorption, and growth. The polypeptide regulates these functions by endocrine, paracrine, neurocrine or luminal mechanisms. Abnormalities of endogenous somatostatin have been implicated in several gastrointestinal disorders, including the somatostatinoma syndrome, antroduodenal D-cell hyperplasia, peptic ulcer, obesity, and liver cirrhosis. Because of its potent inhibitory effects, somatostatin or somatostatin-analogues have been used as therapeutic agents in various clinical conditions, such as upper gastrointestinal haemorrhage, endocrine pancreatic tumours, gastrointestinal and pancreatic fistulas, pancreatitis, secretory diarrhoea, and dumping syndrome. The recent availability of the synthetic long-acting somatostatin-analogue SMS 201-995 (Sandostatin) has greatly facilitated the therapeutical application of somatostatin-polypeptides.

Malignant somatostatinoma presenting with diabetic ketoacidosis

High circulating levels of somatostatin (SRIF) were detected in a patient with a metastatic tumour after development of diabetic ketoacidosis (DKA). Fasting insulin and C-peptide levels were markedly suppressed, but plasma glucagon was not suppressed below normal. Progressive cachexia ensued; at autopsy a poorly differentiated non-small cell neuroendocrine carcinoma metastatic to liver was found. Small gallstones were noted. Electron microscopy of tumour tissue showed neurosecretory granules and tonofilament bundles. Immunohistochemical staining of tumour cells was diffusely positive for carcinoembryonic antigen, bombesin-like immunoreactivity, and calcitonin with focal immunoreactivity for SRIF, serotonin, neuron-specific enolase, chromogranin, and epithelial membrane antigen. Column chromatography of plasma and tumour extract revealed five or more peaks of material with SRIF-like immunoreactivity (SRIF-LI): predominantly SRIF-28 and intermediates in tumour extract, and SRIF-14 and an intermediate between SRIF-28 and SRIF-14 in plasma, DKA in this case of somatostatinoma syndrome may reflect differential effects of tumour production of larger molecular weight SRIF forms on insulin and glucagon secretion.

Pancreatic somatostatinoma

The presence of cholelithiasis, steatorrhea, diabetes mellitus, and a pancreatic tumor initiated a diagnostic workup for somatostatinoma in a 43 year old black woman. The hypothesis of somatostatinoma was supported by a high level of plasma-like immunoreactivity and secretory granules resembling D-cell granules by electron microscopy. The patient has been euglycemic and well since complete resection of the tumor. This is the seventh reported case of somatostatinoma and the second to be benign.