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

Hereditary Syndromes Associated with Pancreatic and Lung Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PanNETs) and lung NETs (LNETs) represent a rare but clinically significant subgroup of neoplasms. While the majority is sporadic, approximately 17% of PanNETs and a subset of LNETs develop in the context of monogenic familial tumor syndromes, especially multiple endocrine neoplasia type 1 (MEN1) syndrome. Other inherited syndromes associated with PanNETs include MEN4, von Hippel-Lindau (VHL) syndrome, neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC). These syndromes are highly penetrant and their clinical manifestations may vary even among members of the same family. They are attributed to genetic mutations involving key molecular pathways regulating cell growth, differentiation, and angiogenesis. Pancreatic NETs in hereditary syndromes are often multiple, develop at a younger age compared to sporadic tumors, and are associated with endocrine and nonendocrine tumors derived from multiple organs. Lung NETs are not as common as PanNETs and are mostly encountered in MEN1 syndrome and include typical and atypical lung carcinoids. Early detection of PanNETs and LNETs related to inherited syndromes is crucial, and specific follow-up protocols need to be employed to optimize diagnosis and management. Genetic screening is recommended in childhood, and diagnostic screening starts often in adolescence, even in asymptomatic mutation carriers. Optimal management and therapeutic decisions should be made in the context of a multidisciplinary team in specialized centers, whereas specific biomarkers aiming to identify patients denoted to follow a more aggressive course need to be developed.

What Are the Place and Modalities of Surgical Management for Pancreatic Neuroendocrine Neoplasms? A Narrative Review

Pancreatic neuroendocrine neoplasms (panNENs) are a heterogeneous group of tumors derived from cells with neuroendocrine differentiation. They are considered malignant by default. However, their outcomes are variable depending on their presentation in the onset of hereditary syndromes, hormonal secretion, grading, and extension. Therefore, although surgical treatment has long been suggested as the only treatment of pancreatic neuroendocrine neoplasms, its modalities are an evolving landscape. For selected patients (small, localized, non-functional panNENs), a "wait and see" strategy is suggested, as it is in the setting of multiple neuroendocrine neoplasia type 1, but the accurate size cut-off remains to be established. Parenchyma-sparring pancreatectomy, aiming to limit pancreatic insufficiency, are also emerging procedures, which place beyond the treatment of insulinomas and small non-functional panNENs (in association with lymph node picking) remains to be clarified. Furthermore, giving the fact that the liver is generally the only metastatic site, surgery keeps a place of choice alongside medical therapies in the treatment of metastatic disease, but its modalities and extensions are still a matter of debate. This narrative review aims to describe the current recommended surgical management for pancreatic NENs and controversies in light of the actual recommendations and recent literature.

Somatostatinoma and Neurofibromatosis Type 1-A Case Report and Review of the Literature

Somatostatinomas are rare neuroendocrine tumors (NET) that arise in the gastrointestinal (GI) tract. Because of their insidious growth, they are usually asymptomatic until late stages, presenting as malignant disease. We report the case of a 50-year-old woman who presented with epigastric abdominal pain, diarrhea and significant weight loss in the last two years. On clinical examination the patient met the criteria for neurofibromatosis type 1 (NF1). Abdominal CT and MRI revealed an infiltrative duodenal mass, with pancreatic invasion, locoregional enlarged lymph nodes and disseminated hepatic nodules. Microscopy and immunohistochemistry uncovered a neuroendocrine tumor, staining positive for chromogranin A (CgA), synaptophysin and somatostatin, with a Ki67 = 1%. Somatostatin receptors (SSTRs) type 2 were negative and SSTRs type 5 were positive in less than 50% of tumoral cells. Our patient was classified as a T3N1M1 stage IV metastatic duodenal grade 1 somatostatinoma and treatment with somatostatin analogues and chemotherapy with capecitabine and temozolomide was started, with so far abdominal imaging follow-up showing stable disease. When a patient is diagnosed with a rare NET, such as a somatostatinoma, it is of utmost importance to determine if it is a sporadic tumor or just a feature of a genetic disorder.

The North American Neuroendocrine Tumor Society Consensus Paper on the Surgical Management of Pancreatic Neuroendocrine Tumors

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the surgical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The group reviewed a series of questions of specific interest to surgeons taking care of patients with pancreatic neuroendocrine tumors, and for each, the available literature was reviewed. What follows are these reviews for each question followed by recommendations of the panel.

Pancreatic neuroendocrine tumors

PURPOSE OF REVIEW

Pancreatic neuroendocrine tumors (pNETs) are a rare, heterogeneous group of pancreatic neoplasms with a wide range of malignant potential. They may manifest as noninfiltrative, slow-growing tumors, locally invasive masses, or even swiftly metastasizing cancers.

RECENT FINDINGS

In recent years, because of the increasing amount of scientific literature available for pNETs, the classification, prognostic stratification criteria, and available consensus guidelines for diagnosis and therapy have been revised and updated.

SUMMARY

The vast majority of new pNET diagnoses consist of incidentally discovered lesions on cross-sectional imaging. The biologic behavior of pNETs is defined by the grade and stage of the tumor. Surgery is the only curative treatment and it, therefore, represents the first therapeutic choice for any localized pNET; however, recent evidence suggests that patients with small (<2 cm), nonfunctioning G1 tumors can be safely observed.An aggressive surgical approach towards liver metastases is recommended in selected cases, as well as liver-directed therapies for disease control. In the presence of unresectable progressive disease, somatostatin analogs, targeted therapies such as everolimus, peptide receptor radionuclide therapy, and systemic chemotherapy are all useful tools for prolonging survival.

Somatostatinoma Presented as Double-Duct Sign

Somatostatinoma is a rare neuroendocrine tumor with an incidence rate of 1 in 40 million people. It presents mostly as asymptomatic tumor diagnosed incidentally on imaging or surgery when evaluating or treating possible causes of abdominal pain. It also can present with vague symptoms, or as a clinical triad of glucose intolerance, steatorrhea, and achlorhydria. The majority of somatostatinomas are present in the pancreatic head, followed by the duodenum, the pancreatic tail, and rarely the ampulla of Vater. The prognosis is poor as more than 77% of cases present as advanced disease with local invasion or distant metastasis. Surgical resection is the main treatment for early stage disease. Other treatment options include somatostatin analogue, molecular targeted therapy, and cytotoxic chemotherapy. The scarcity of somatostatinoma cases led to the lack of fully formulated treatment options. Herein, we present a 43-year old male patient who was referred by his primary care physician to our gastroenterology clinic due to elevated liver function test and double-duct sign on CT scan. We performed an ERCP, which revealed 2 cm ampullary lesion with upstream obstruction. Biopsies were taken and histopathology was unrevealing. He underwent a laparoscopic pancreaticoduodenectomy with histopathology revealed stage IIb somatostatinoma. Treating physicians should hold a high index of suspicion and maintain a broad differential diagnosis of elevated liver enzymes.

Duodenal somatostatinoma presenting as obstructive jaundice with the coexistence of a gastrointestinal stromal tumour in neurofibromatosis type 1: a case with review of the literature

Somatostatinomas are rare neuroendocrine tumours, mostly located in the pancreas or duodenum, with an estimated incidence of 1 in 40 million. Duodenal somatostatinomas (DSs) are usually found in association with neurofibromatosis type 1 (NF1), tuberous sclerosis and Von Hippel-Lindau syndrome. Gastrointestinal stromal tumours (GIST) have also been described in NF1, but the association with somatostatinoma is very uncommon. We report the case of a patient with NF1 who presented with obstructive jaundice due to multiple firm nodules around the ampulla of Vater. A pancreaticoduodenectomy was performed and revealed a 1 cm duodenal/ampullary mass which stained positive for somatostatin, together with a GIST also found on the duodenal wall. Despite its rarity, ampullary somatostatinomas should be considered in the differential diagnosis of biliary tract dilation in patients with NF1.

Neoplasms of the Neuroendocrine Pancreas: An Update in the Classification, Definition, and Molecular Genetic Advances

This review focuses on discussing the main modifications of the recently published 2017 WHO Classification of Neoplasms of the Neuroendocrine Pancreas (panNEN). Recent updates separate pancreatic neuroendocrine tumors into 2 broad categories: well-differentiated pancreatic neuroendocrine tumors (panNET) and poorly differentiated pancreatic neuroendocrine carcinoma (panNEC), and incorporates a new subcategory of "well-differentiated high-grade NET (G3)" to the well-differentiated NET category. This new classification algorithm aims to improve the prediction of clinical outcomes and survival and help clinicians select better therapeutic strategies for patient care and management. In addition, these neuroendocrine neoplasms are capable of producing large quantity of hormones leading to clinical hormone hypersecretion syndromes. These functioning tumors include, insulinomas, glucagonomas, somatostatinomas, gastrinomas, VIPomas, serotonin-producing tumors, and ACTH-producing tumors. Although most panNENs arise as sporadic diseases, a subset of these heterogeneous tumors present as parts on inherited genetic syndromes, such as multiple endocrine neoplasia type 1, von Hippel-Lindau, neurofibromatosis type 1, tuberous sclerosis, and glucagon cell hyperplasia and neoplasia syndromes. Characteristic clinical and morphologic findings for certain functioning and syndromic panNENs should alert both pathologists and clinicians as appropriate patient management and possible genetic counseling may be necessary.

Neurofibromatosis type 1-associated multiple rectal neuroendocrine tumors: A case report and review of the literature

Neurofibromatosis type 1 (NF-1) is commonly associated with benign or malignant tumors in both the central and peripheral nervous systems. However, rare cases of NF-1-associated multiple rectal neuroendocrine tumors have been reported. This report describes a case of a 39 year old female with NF-1 and intermittent hematochezia as a primary symptom. Physical examination showed multiple subcutaneous nodules and café au lait spots with obvious scoliosis of the back. Imaging examinations and colonoscopy found malformation of the left external iliac vein and multiple gray-yellow nodules with varying sizes and shapes in the rectal submucosal layer. Histological and immunohistochemical results suggested multiple rectal neuroendocrine tumors, a rare disease with few appreciable symptoms and a particularly poor prognosis. The patient with NF-1 presented here had not only multiple rectal neuroendocrine neoplasms but also vascular malformations, scoliosis and other multiple system lesions. This case therefore contributes to improving clinical understanding, diagnosis and treatment of related complications for patients with NF-1 who present with associated medical conditions.

Hereditary syndromes predisposing to endocrine tumors and their skin manifestations

We often think of the lentiginoses, phacomatoses and other neurocutaneous syndromes as conditions that affect the skin and also predispose to a variety of tumors. However, we rarely think of Peutz-Jeghers syndrome (PJS), Carney complex (CNC), Cowden disease (CD), neurofibromatosis type-1 (NF-1) or tuberous sclerosis (TSC) as conditions that are multiple endocrine neoplasias (MEN). Indeed, all of these conditions predispose to a variety of endocrine tumors, in addition to many other neoplasms. On the other hand, the classic MENs, type 1 and 2 (MEN-1 and MEN-2, respectively) are almost never thought in terms of their skin manifestations. In this review, we present extensively the MEN-1, MEN-2 and PJS syndromes, and briefly refer to CD, NF-1, and TSC. CNC is discussed in another article in this journal issue.

Somatostatinoma of the Ampulla: An Incidental Postoperative Finding Following Colorectal Cancer Resection

Somatostatinoma of the gastrointestinal tract is a rare finding, especially arising from the ampulla of Vater. We present a man recently diagnosed with rectal adenocarcinoma who was found on imaging to have an ampullary mass. Histology and immunohistochemical staining of the biopsied tissue were consistent with a nonfunctioning somatostatinoma. The patient had neurofibromatosis, which have been reported in patients with ampullary somatostatinomas. Our case highlights the importance of gastrointestinal findings in those with underlying genetic conditions.

The Coexistence of Somatostatinoma and Gastrointestinal Stromal Tumor in the Duodenum of a Patient with Von Recklinghausen's Disease

We herein describe a case of somatostatinoma coexisting with a gastrointestinal stromal tumor (GIST) in the duodenum of an 81-year-old woman with Von Recklinghausen's disease (VRD) and common bile duct stone who presented with diarrhea of three months in duration. Gastroduodenoscopy revealed an ulcer on the second part of the duodenum. A 2.1-cm enhancing tumor was observed to extend from the ulcer on an abdominal computed tomography scan. Subtotal stomach-preserving pancreaticoduodenectomy revealed a somatostatinoma on the papilla of the vater and duodenal GIST. There have been only eight reports on VRD associated with ampullary somatostatinoma and GIST. An awareness of this possibility in patients with gastrointestinal lesions is necessary for proper treatment and patient management.

Synchronous neuroendocrine tumor and non-small-cell lung cancer in neurofibromatosis type 1

Neurofibromatosis type 1 is a common cancer predisposing condition. Tumors, particularly gastrointestinal tumors, are commonly associated with NF1 but are not widely known. In addition, the relationship between lung cancer and neurofibromatosis has been controversial until recently with the discovery of oncogenes such as p53.

Non-functional neuroendocrine tumors of the pancreas: Advances in diagnosis and management

Nonfunctional neuroendocrine tumors of the pancreas (NF-PNETs) are a heterogeneous group of neoplasms. Although rare, the incidence of NF-PNETs is increasing significantly. The classification of PNETs has evolved over the past decades and is now based on a proliferation grading system. While most NF-PNETs are slow growing, tumors with more aggressive biology may become incurable once they progress to unresectable metastatic disease. Tumors of higher grade can be suspected preoperatively based on the presence of calcifications, hypoenhancement on arterial phase computed tomography, positron emission technology avidity and lack of octreotide scan uptake. Surgery is the only curative treatment and is recommended for most patients for whom complete resection is possible. Liver-directed therapies (thermal ablation, transarterial embolization) can be useful in controlling unresectable hepatic metastatic disease. In the presence of unresectable progressive disease, somatostatin analogues, everolimus and sunitinib can prolong progression-free survival. This article provides a comprehensive review of NF-PNETs with special emphasis on recent advances in diagnosis and management.

Gastrinoma and neurofibromatosis type 2: the first case report and review of the literature

BACKGROUND

Gastroenteropancreatic neuroendocrine tumors have occasionally been described in association with neurofibromatosis type 1, whereas an association with neurofibromatosis type 2 has never been reported.

CASE PRESENTATION

This report refers to an Italian 69 year old woman with neurofibromatosis type 2 and a pancreatic gastrinoma. In the past she had encephalic meningiomas, a tongue schwannoma and bilateral acoustic neurinomas. She presented with weight loss and a long-term history of diarrhea, responsive to proton pump inhibitors. Upper gastrointestinal endoscopy revealed peptic ulcer of the duodenal bulb. Blood tests were normal, except for the elevation of plasma gastrin (1031 pg/ml; reference value <108) and chromogranin A (337 U/L; reference value <36). After secretin stimulation testing, the plasma gastrin level rose to 3789 pg/ml. The abdomen magnetic resonance imaging and gallium68-DOTATOC positron emission tomography scan demonstrated the presence of a 1.2 x 2 cm lesion in the pancreatic head and a liver metastatis. Pancreatic endoscopic ultrasound with fine needle aspiration revealed cytomorphologic features suggestive of pancreatic gastrinoma. Brain magnetic resonance showed a pituitary microadenoma. There was no evidence of hyperparathyroidism. The genetic test for multiple endocrine neoplasia type 1 syndrome mutation was negative.

CONCLUSION

This report focuses on the first case of coexistence of gastrinoma with neurofibromatosis type 2. Although the clinical relevance of this association remains to be determined, our case report will surely give cause for due consideration.

Pathologic grade and tumor size are associated with recurrence-free survival in patients with duodenal neuroendocrine tumors

BACKGROUND

Duodenal neuroendocrine tumors are rare and few studies exist to guide surgical management. This study identifies factors associated with recurrence after resection.

METHODS

A retrospective, single institution review was performed between 1983 and 2011 on patients with a pathologic diagnosis of duodenal neuroendocrine tumor. Tumor grade was assigned based on WHO 2010 criteria (Ki-67 and mitotic rate).

RESULTS

Seventy-five patients were identified that underwent curative resection. This included 12 patients with endoscopic mucosal resection, 34 that had local resection, and 29 that underwent pancreaticoduodenectomy. Two-year and 5-year recurrence-free survival was 84 and 81%, respectively. There were 11 tumor recurrences (either local or distant), and four patients died of their disease (3/4 had high-grade lesions) with an overall median follow-up of 27 months. On univariate analysis, tumor size and tumor grade were identified as being associated with recurrence, but not intervention type, lymph node metastases, ampullary location, or margin status.

CONCLUSIONS

Tumor grade and size are associated with recurrence-free survival in duodenal neuroendocrine tumors. When feasible, a less aggressive surgical approach to treat low-grade and low-stage duodenal NETs should be considered.

Somatostatinoma syndrome: a challenging differential diagnosis among pancreatic tumors

Among the neuroendocrine neoplasia, the pancreatic somatostatin-producing tumors are very rare. Usually functional, these tumors produce the somatostatinoma syndrome, which encompasses diabetes mellitus, diarrhea/steatorrhoea, and cholelithiasis. Other symptoms may include dyspepsia, weight loss, anemia, and hypochlorhydria. All theses symptoms are explained by the inhibitory actions of the somatostatin released by tumoral cells originated from pancreatic delta cells or endocrine cells of the digestive tract. The diagnosis is easy to overlook since these symptoms are commonly observed in other more common syndromes. Besides the clinical features, diagnosis is based on serum determination of somatostatin, and imaging exams, such as ultrasound, computer tomography and positron emission tomography. Pathologic examination is characterized by the positivity of immunohistochemical reaction for synaptophysin, chromogranin, and somatostatin. These tumors can be classified according to tumor size, mitotic index, neural or vascular invasion, and distant metastases. The authors describe the case of a 61-year-old female patient who sought medical care because of a 6-month history of watery diarrhea, weight loss, and depression. She was diagnosed with diabetes mellitus 3 years ago. Imaging examination revealed a tumoral mass of 4 cm in its longest axis in the topography of the head of the pancreas and calculous cholecistopathy. The patient’s clinical status was unfavorable for a surgical approach. She died after 20 days of hospitalization. The definitive diagnosis was achieved with the autopsy findings, which disclosed a pancreatic somatostatinoma.

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.

A case of pancreatic neuroendocrine tumor in a patient with neurofibromatosis-1

Patients with neurofibromatosis-1 (NF-1) sometime develop neuroendocrine tumors (NET). Although these NETs usually occur in the duodenum or peri-ampullary region, they occasionally grow in the pancreas (PNET). A 62-year-old man with NF-1 had mild liver dysfunction and was admitted to our hospital for further examination. An abdominal contrast-enhanced computed tomography scan demonstrated a 30-mm tumor in the head of the pancreas. The scan showed an invasion of the tumor into the duodenum, and biopsy under an endoscopic ultrasonography indicated that the tumor was a NET. A subtotal stomach-preserving pancreaticoduodenectomy was performed. Macroscopically, the pancreatic tumor was white and elastic hard. Microscopically, tumor cells were composed of ribbons, cords, and solid nests with an acinus-like structure. The tumor was diagnosed as NET G2 according to the WHO classification (2010). The product of the NF-1 gene, i.e., neurofibromin, was weakly positive in the tumor cells, suggesting that the tumor was induced by a mutation in the NF-1 gene. This is the seventh case of PNET arising in NF-1 patients worldwide.

Pancreatic endocrine neoplasms: a current update on genetics and imaging

Pancreatic endocrine neoplasms are rare pancreatic tumours that may occur sporadically or as part of inherited syndromes such as multiple endocrine neoplasia-1 syndrome, von Recklinghausen disease, von Hippel-Lindau syndrome and tuberous sclerosis complex. Recent advances in the genetics and pathology of hereditary syndromes have provided valuable insights into the pathophysiology and biology of sporadic pancreatic endocrine neoplasms. Evolving molecular data on the biology of these neoplasms have the potential for diagnostic, therapeutic and prognostic use.

Well-differentiated pancreatic neuroendocrine tumors: from genetics to therapy

Well-differentiated pancreatic neuroendocrine tumors (PanNETs) comprise ∼1-3% of pancreatic neoplasms. Although long considered as reasonably benign lesions, PanNETs have considerable malignant potential, with a 5-year survival of ∼65% and a 10-year survival of 45% for resected lesions. As PanNETs have a low incidence, they have been understudied, with few advances made until the completion of their exomic sequencing in the past year. In this Review, we summarize some of the latest insights into the genetics of PanNETs, and their probable implications in the context of prognosis and therapy. In particular, we discuss two genes (DAXX and ATRX) that have collectively been identified as mutated in >40% of PanNETs, and the biological and prognostic implications of these novel mutations. The identification of recurrent somatic mutations within the mTOR signaling pathway and the therapeutic implications for personalized therapy in patients with PanNETs are also discussed. Finally, this Review outlines state-of-the-art advances in the biology of PanNETs that are of emerging translational importance.

Pancreatic and peripancreatic somatostatinomas

BACKGROUND

Somatostatinomas are rare neuroendocrine tumours with an annual incidence of 1 in 40 million. They arise in the pancreas or periampullary duodenum. Most are clinically non-secretory and do not cause the somatostatinoma syndrome. Many are metastatic at presentation and their management is typically multimodal.

CASE HISTORIES

Four cases of somatostatinoma are described. Two patients with periampullary disease presented with biliary obstruction, one with frank jaundice and one with incidental bile duct obstruction on investigation of hepatitis B. Each patient had type 1 neurofibromatosis and resection of the somatostatinoma by means of a pylorus-preserving proximal pancreaticoduodenectomy has resulted in long-term survival. Another two patients with metastatic pancreatic somatostatinomas presented with abdominal pain. Contrasting management illustrates current treatment strategies that are dependent in part on the distribution of the disease.

DISCUSSION

The pathophysiology, presentation, clinical associations and role of diagnostic imaging are discussed for periampullary and pancreatic neuroendocrine tumours. Operative treatment has an important role in both the curative and palliative settings in conjunction with appropriate medical treatments and these are described. Management options depend on the extent of the disease and the cases are used to illustrate the rationale of such strategies.

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.

Pancreatic endocrine tumors

The endocrine cells of the pancreas and their related cells throughout the gastrointestinal tract give rise to a variety of tumors that pose a diagnostic challenge. There has been progress in understanding their histogenesis, morphology, immunohistochemistry, molecular biology and classifications. This review will focus on nomenclature/terminology, classification, the role of immunohistochemistry, molecular advances, including genetic predisposition, and potential therapeutic targets to define the role of pathology in the application of prognostic and predictive markers for this disease.

Endocrine tumours of the pancreas

Verbeke C S (2010) Histopathology 56, 669-682 Endocrine tumours of the pancreas Histopathology reporting of pancreatic endocrine neoplasms is complex. The tumours can exhibit a variety of morphological appearances, which often require careful differential diagnostic consideration. Prediction of tumour behaviour and clinical outcome is based on the World Health Organization classification and TNM staging and grading system, which share some criteria and premises, but differ significantly in others. Clinicopathological correlation through discussion at multidisciplinary team meetings is of paramount importance. In this review special emphasis is given to the items of information that can and should be provided by the pathologist to allow optimal patient management. The review further discusses areas of current controversy and uncertainty, of which pathologists participating in multidisciplinary discussions should be aware.

Endocrine tumours in neurofibromatosis type 1, tuberous sclerosis and related syndromes

Neurofibromatosis type 1 (NF-1) and tuberous sclerosis complex (TSC) are two familial syndromes known as phakomatoses that may be associated with endocrine tumours. These hereditary cutaneous conditions affect the central nervous system and are characterised by the development of hamartomas. Over the past 20 years, there have been major advances in our understanding of the molecular basis of these diseases. Both NF-1 and TSC are disorders of unregulated progression through the cell cycle, in which causative genes behave as tumour suppressor genes. The pathogenesis of these familial syndromes is linked by the shared regulation of a common pathway, the protein kinase mammalian target of rapamycin (mTOR). Additional related disorders that also converge on the mTOR pathway include Peutz-Jeghers syndrome and Cowden syndrome. All of these inherited cancer syndromes are associated with characteristic skin findings that offer a clue to their recognition and treatment. The discovery of mTOR inhibitors has led to a possible new therapeutic modality for patients with endocrine tumours as part of these familial syndromes.

Periampullary and duodenal neoplasms in neurofibromatosis type 1: two cases and an updated 20-year review of the literature yielding 76 cases

BACKGROUND

Patients with neurofibromatosis type 1 (NF1) are at increased risk to develop tumors throughout the gastrointestinal tract, including neuromas, gastrointestinal stromal tumors (GIST), and periampullary somatostatin-rich carcinoids. Here, we briefly describe two male patients with NF1 and review the recent literature on this topic.

METHODS

Databases for PubMed and MEDLINE were searched for English-language articles since 1989 using a list of keywords, as well as references from review articles.

RESULTS

The results generated by the search yielded 50 articles and 74 cases. Patients most commonly presented with jaundice, weight loss, GI bleeding, or anemia. The mean age at presentation was 47.9 years, with 59% of patients being female. Mean tumor size was 3.8 cm (range 0.9-27 cm). Tumor location was the duodenum (60%), ampulla (31%), pancreas (5%), or bile duct/gallbladder (4%). Tumor type was reported as somatostatinoma (40%), GIST (34%), adenocarcinoma (8%), carcinoid (6%), neurofibroma (5%), schwannoma (4%), or gangliocytic paraganglioma (3%). Treatment included classic Whipple procedure (42%), local excision (25%), pylorus-preserving pancreaticoduodenectomy (17%), and other resection (6%). Mean follow-up was 31 months postresection (range 0-99 months): 75% of patients were alive with no evidence of disease.

CONCLUSIONS

These results underscore the importance of a thorough evaluation for tumors in NF1 patients with gastrointestinal symptoms, as well as subsequent surgical management when findings suggest a tumor in the periampullary region, as resection remains the mainstay of treatment.

Gastric Neuroendocrine Carcinomas in Bearded Dragons (Pogona vitticeps)

This article describes a newly recognized highly malignant neoplastic entity in young bearded dragons ( Pogona vitticeps), gastric neuroendocrine carcinomas, which readily metastasize. Ten bearded dragons with histories of anorexia (8), vomiting (3), hyperglycemia (2), and anemia (3) were included in this study. All animals had neoplastic masses in their stomach, with metastasis to the liver. Microscopically, 6 of these neuroendocrine carcinomas were well-differentiated and 4 were poorly differentiated. For further characterization, immunohistochemistry for protein gene product 9.5, neuron-specific enolase, endorphin, chromogranins A and B, synaptophysin, somatostatin, insulin, glucagon, gastrin, pancreatic polypeptide, and vasoactive intestinal peptide was performed on 5 animals. Because only immunolabeling for somatostatin was consistently observed in all neoplasms, a diagnosis of somatostatinoma was made for these 5 bearded dragons. Some neoplasms also exhibited multihormonal expression. Electron microscopy performed on 1 tumor confirmed the presence of neuroendocrine granules within neoplastic cells. Gastric neuroendocrine carcinomas, and specifically somatostatinomas, have not been previously reported in bearded dragons, or other reptiles, and may be underdiagnosed due to inconsistent, ambiguous clinical signs. In humans, pancreatic somatostatinomas are associated with a syndrome of hypersomatostatinemia, which includes hyperglycemia, weight loss, and anemia, as observed in some of these bearded dragons. Somatostatinomas in humans are commonly associated with neurofibromatosis type 1 (Von Recklinghausen's disease), caused by a mutation in the tumor suppressor gene NF1, which results in decreased expression of neurofibromin. In all 5 animals examined, neoplasms exhibited decreased neurofibromin expression compared with control tissues, suggesting that decreased functional neurofibromin may play a role in the pathogenesis of somatostatinomas in bearded dragons.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Somatostatinoma: clinico-pathological features of three cases and literature reviewed

Somatostatinoma is a rare endocrine tumor that comprises around 1% of all gastroenteropancreatic endocrine neoplasms. This paper gives an updated review on somatostatinoma and describes three sporadic cases of somatostatinoma located in the pancreas, duodenum, and jejunum. Approximately 200 case histories of somatostatinoma have been published, with the duodenum being the most frequent site, followed by the pancreas. Somatostatinomas may be sporadic or associated with neurofibromatosis type 1, Multiple Endocrine Neoplasia type 1, and Von Hippel-Lindau syndromes. Functional somatostatinomas release excessive amounts of somatostatin suppressing gallbladder motility and inhibiting the secretory activity of various endocrine and exocrine cell types. A triad of mild diabetes mellitus, cholelithiasis, and diarrhea/steatorrhoea characterizes the somatostatinoma or 'inhibitory' syndrome. Non-functional somatostatinomas tend either to be asymptomatic or to present with obstructive symptoms. These tumors are often malignant and by the time they are detected, nearly two-thirds have already metastasized to the regional lymph nodes or the liver. A comparison between our three cases and those in the literature provides useful insights into the clinical management of these patients. Interestingly, the jejunal somatostatinoma described here is the second case ever reported.

[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.

Incidental small ampullary somatostatinoma treated with ampullectomy 2 years after diagnosis

Somatostatinomas are rare tumors; ampullary somatostatinomas are very rare. We report a case of a small pure somatostatin-producing neuroendocrine tumor of ampulla of Vater in a 54-year-old woman with neither neurofibromatosis nor somatostatinoma syndrome, "incidentally" discovered during an abdominal computed tomography. The patient initially refused other adjunctive exams but after 2 years she was admitted, presenting with itch, night sweats, severe fatigue, and unintentional weight loss. The size of the tumor (1.5 cm) and the other radiologic findings had not changed since the abdominal CT scan 2 years before. The somatostatin, gastrin, glucagons, serotonin, vasoactive intestinal peptide, dopamine, norepinephrine, epinephrine, and calcitonin plasma levels were normal. ERCP-obtained biopsies revealed a neuroendocrine tumor with psammoma bodies; immunohistochemical profile was positive for chromogranin and somatostatin. The patient underwent surgery; intraoperative histologic examination of lymph nodes sampling of perihepatic and periduodenal lymph nodes was negative for metastasis. We performed, therefore, a transduodenal ampullectomy. The patient continues to do well at 3 years' follow-up with no evidence of local or distance recurrence of disease.

[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.

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.

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.

[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.

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.