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.

Somatostatinoma of the first jejunal loop in a patient with neurofibromatosis von Recklinghausen and bilateral pheochromocytoma.

Somatostatinoma is a rare neuroendocrine tumor which especially develops in the pancreas. There are few communicated cases about extra-pancreatic localization, having as a particularity the absence of somatostatin hypersecretion syndrome and frequent association with von Recklinghausen neurofibromatosis. We present the case of a 42-year old patient with Von Recklinghausen neurofibromatosis admitted in our clinic with a chronic upper digestive obstruction syndrome. The presence of a first jejunal loop somatostatinoma was an intraoperative surprising diagnosis that imposed jejunal resection and association of complementary specific treatment. Despite the therapeutic correct management, the status of the patient deteriorated very fast, confirming the aggressiveness of this neoplasia.

Pancreatic neuroendocrine tumors: clinical features, diagnosis and medical treatment: advances.

Pancreatic neuroendocrine tumors (pNETs) comprise with gastrointestinal carcinoids, the main groups of gastrointestinal neuroendocrine tumors (GI-NETs). Although these two groups of GI-NETs share many features including histological aspects; over-/ectopic expression of somatostatin receptors; the ability to ectopically secrete hormones/peptides/amines which can result in distinct functional syndromes; similar approaches used for tumor localization and some aspects of treatment, it is now generally agreed they should be considered separate. They differ in their pathogenesis, hormonal syndromes produced, many aspects of biological behaviour and most important, in their response to certain anti-tumour treatment (chemotherapy, molecular targeted therapies). In this chapter the clinical features of the different types of pNETs will be considered as well as aspects of their diagnosis and medical treatment of the hormone-excess state. Emphasis will be on controversial areas or recent advances. The other aspects of the management of these tumors (surgery, treatment of advanced disease, tumor localization) are not dealt with here, because they are covered in other chapters in this volume.

[Diagnostics and treatment in functional pancreatic neuroendocrine tumours]. / Diagnostik und Therapie bei funktionell aktiven pankreatischen neuroendokrinen Tumoren.

Pancreatic neuroendocrine tumours (PNET) are rare entities with an annual incidence of < 100,000. About 1 - 2 % of pancreatic neoplasias are neuroendocrine tumours. About one third of these tumours secrete biologically active substances that lead to development of specific clinical syndromes. PNET may occur sporadically or in association with hereditary syndromes, such as multiple endocrine neoplasia type 1 (MEN1). Among the functional PNET, insulinomas and gastrinomas are the most common entities. In contrast, vasoactive intetinale peptide (VIP)-secreting tumours, glucagonomas, serotonin-secreting carcinoid tumors, and tumours with secretion of ectopic hormones, such as calcitonin, are extremely rare. Once diagnosis has been established on the basis of clinical and laboratory findings, localization of the source of pathologic hormone secretion is warranted. Imaging methods frequently used for localization of PNET comprise anatomical imaging modalities, computed tomography, and magnetic resonance imaging, endoscopic ultrasound, selective arterial catheterization with hepatic venous sampling, DTPA-octreotid scintigraphy and DOTA-D-Phe(1)-Tyr(3)-octreotid positron emission tomography. Therapy is based on the specific tumour entity and the extent of the disease. In the majority of patients, even in the case of malignant disease, a surgical approach is warranted, eventually combined with a medical treatment.

Tumores neuroendocrinos del páncreas / Pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors are infrequent and slow-growing neoplasms. They are classified basedon their clinical presentation as functioning and nonfunctioning tumors. The most common functionaltumors are the insulinoma and gastrinoma. They can be sporadic or be part of hereditary forms as MEN-1.The diagnosis is based on the detection of the specific clinical syndrome in association of high levels of the substance secreted by the tumor and conventional imaging studies or others such as stimulation tests, somatostatin receptor scintigraphy and endoscopic ultrasound. In general, these tumors have a better prognosis than the pancreatic adenocarcinoma and they can show metastasis to the liver and infrequently, in bones. The treatment can be managed medically diminishing the inappropriate secretion of the substances by the tumor using, for example, the somatostatin analogs. Surgery should be always considered, especially in case of insulinomas, small non-functioning tumors, and small gastrinomas that can be managed with surgery enucleation. More advanced resective surgery, such as Whipple resection, are not routinely recommended and they should be limited to selected patients. In advanced tumors, there are other treatment alternatives, for example, hepatic resection, radiofrequency, chemotherapy and new agents such as sunitinib and everolimus.

Los tumores neuroendocrinos pancreáticos son infrecuentes y de crecimiento lento. Se clasifican en tumores funcionantes o no funcionantes (TNEP-NF), de acuerdo a la presentación clínica. Los tumores funcionantes más frecuentes son los insulinomas y los gastrinomas. Pueden ocurrir en forma esporádica o asociados a síndromes hereditarios como la NEM- 1, entre otros. El diagnóstico se basa en la detección del síndrome clínico específico asociado a la demostración de niveles elevados de la sustancia secretada y exámenes imagenológicos convencionales u otros más específicos como de estimulación, cintigrafía de receptores de somatostatina y endosonografía. En general, tienen mejor pronóstico que los adenocarcinomas pancreáticos y pueden dar metástasis hepáticas y con menor frecuencia, óseas. El tratamiento puede ser médico disminuyendo la secreción inapropiada de las sustancias producidas por el tumor como los análogos de somatostatina. La cirugía siempre debe ser considerada, especialmente en caso de insulinomas, pequeños TNEP-NF, y gastrinomas pequeños, que pueden ser tratados con enucleación quirúrgica. Las cirugías resectivas más avanzadas, como la operación de Whipple no están recomendadas en forma rutinaria y sólo deben ser utilizadas en pacientes seleccionados. En casos de tumores avanzados, existen alternativas de tratamiento, como la resección hepática, radiofrecuencia, quimioterapia, y terapia con nuevos agentes en estudio como el sunitinib y everolimus.

Neuroendocrine tumors of the pancreas.

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

[Rare pancreatic endocrine tumors]. / Rzadkie guzy endokrynne trzustki.

Functional pancreatic endocrine tumors other than gastrinoma and insulinoma are quite rare. Some of these tumors may be part of multiple endocrine neoplasia type one (MEN-1) syndrome or phakomatoses. Depending on their cell type, functional pancreatic endocrine tumors may cause distinct clinical endocrine syndromes, such as the 'glucagonoma syndrome', Verner-Morrison syndrome and the 'somatostatinoma syndrome'. The significant progress made in recent years, especially in the field of imaging procedures, has brought about great improvement in the identification and differentiation of these neoplasms. Currently, the only curative treatment for islet cell tumors is complete surgical resection. The medical treatment of endocrine pancreatic tumours consists of somatostatin analogues, chemotherapy, and interferon-alpha. The purpose of this manuscript is to provide an overview of the contemporary etiopathogenesis, diagnosis and treatment of rare pancreatic endocrine tumors.

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.

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.

[Pancreatic neuroendocrine tumors]. / Tumores neuroendocrinos del páncreas.

All pancreatic neuroendocrine tumors derive from Langerhans islet cells and have a low incidence. Half of them are functioning tumors that produce diverse hormones and occasionally cause serious clinical endocrine syndromes. They may be malignant, but they have a better survival, if compared to pancreatic ductal adenocarcinoma. Insulinoma, gastrinoma, glucagonoma, VIPoma (VIP=vasoactive intestinal peptide), somatostatinoma and ACTHoma are functioning tumors and they may also be part of Multiple Endocrine Neoplasia type I (MEN 1) syndrome and of von Hippel-Lindau disease. Diagnosis of non-functioning tumors is usually late, when they reach a big size and have even developed nodal and hepatic metastases. Nowadays, there are effective medical treatments for the medical problems secondary to excessive hormone production. For example, the hypergastrinemia typical of the Zollinger-Ellison syndrome in gastrinoma, can be adequately managed. Surgical resection is the most advisable therapy for pancreatic endocrine tumors, especially when they are small, when long time survival is better. Pre and intra operative imagenology is a great aid to locate these tumors. There are several surgical alternatives, according to the tumor size and location within the pancreas. Furthermore, palliative therapy can be used in disseminated disease. Treatment success is the result of a multidisciplinary medical team work of endocrinologists, surgeons, gastroenterologists, pathologists and geneticists.

[Neuroendocrine tumors of the digestive system]. / Az emésztórendszer neuroendokrin daganatai.

Despite their rare occurrence, gastroenteropancreatic neuroendocrine tumors have been in the centre of interest because of the wide scale and variability of clinical signs and symptoms associated with oversecretion of different hormones. In the present review the authors summarize epidemiological data, pathologic findings, clinical symptoms, as well as diagnostic and therapeutic methods presently available for the management of patients with gastroenteropancreatic neuroendocrine tumors. In addition to surgical treatment and receptor-specific radionuclide therapy used in cases with surgically noncurable tumors, the therapeutic use of somatostatin analogues in recent years has resulted an important advance in the management of patients with these tumors. Somatostatin analogues alone or in combination with other pharmacological therapies may be used effectively for elimination of symptoms of hormonal oversection and, in a number of cases, for diminishing tumor progression.

Islet cell tumors of the pancreas: the medical oncologist's perspective.

Islet cell tumors of the pancreas are rare, indolent, neuroendocrine tumors. Approximately 50% of the patients diagnosed with these tumors present with symptoms related to various biologically active hormones that are secreted by these neoplasms. Currently, the only curative treatment for islet cell tumors is complete surgical resection. Management of metastatic disease is conservative. Initial treatment of these tumors includes expectant observation and medical management of symptoms with clinical monitoring and serial CT scans to assess tumor growth. Patients with rapidly progressive disease, with local symptoms caused by tumor bulk, or with uncontrolled symptoms related to hormone secretion require more aggressive medical or surgical intervention. The somatostatin analogue octreotide may help control hormone secretion and stabilize tumor growth. Patients refractory to octreotide with tumor predominantly in the liver are potential candidates for mechanical ablative techniques, such as hepatic arterial embolization. Radiofrequency ablation and cryosurgical techniques may also be useful, although specific data are limited. Surgical resection of metastatic disease may offer palliative relief of symptoms related to hormone secretion in carefully selected patients. Chemotherapy may be used for palliation when ablative techniques have failed or when significant extrahepatic disease is present. Streptozicin-based combinations remain the first line standard, but major objective responses are less common than had been previously thought. Because of the overall modest success of current chemotherapeutic regimens, patients with advanced disease in need of treatment should be encouraged to enroll in clinical trials testing newer antineoplastic agents or newer treatment strategies.

[Glucagonoma--somatostatinoma]. / Glukagonom--Somatostatinom.

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.

[Apudomas: nosographic and physiopathological aspects]. / Apudomi. Aspetti nosografici e fisiopatologici.

The authors intend to contribute to the knowledge of this complex and in part not fully defined subject of apudomas, in particular with regard to classification criteria and physiopathological aspects. After having examined the characteristics of these neoplasias (probably common embryonal origin, similar radioimmunological, immunohistochemical and ultrastructural characteristics, the capacity to convert amine precursors into amines), the authors focus on the most significant aspect of these carcinoids which, in the light of current knowledge, possess varying but undisputed degrees of biological aggressiveness. They also highlight the importance of the gastroenteric tract as an organ with an endocrine function and lastly affirm the value of the classification which, using the pancreas as the reference organ, distinguishes endocrine neoplasias in this tract into entopic and ectotopic examples.