Imaging of neuroendocrine tumors

[Neuroendocrine tumors of the pancreas]

CLINICAL/METHODOLOGICAL ISSUE

Neuroendocrine tumors (NET) of the pancreas fall into the group of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN). The assignment of imaging morphological criteria to this heterogeneous group of complex tumors is often difficult.

STANDARD RADIOLOGICAL METHODS

Diagnostic ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography-CT (PET/CT) are available for the detection of pancreatic NET (also referred to as NEN) and for the diagnosis of spread and the search for metastases.

METHODOLOGICAL INNOVATIONS

In particular, nuclear medicine examination methods with somatostatin analogues are of high value, since they make tumors visible with high sensitivity via radioactively labeled receptor ligands.

PERFORMANCE

CT and MRI have high detection rates of pancreatic NET. Further developments, such as diffusion imaging, have further improved these traditional cross-sectional imaging diagnostics. However, nuclear medicine methods are an important component in detection and are superior to CT and MRI.

ACHIEVEMENTS

It is important for the radiologist to be familiar with NET of the pancreas, as it is an important differential diagnosis-also with regard to prognosis-of other pancreatic lesions.

PRACTICAL RECOMMENDATIONS

Because NET are often hypervascularized, a biphasic examination technique after contrast administration is mandatory for cross-sectional imaging. PET/CT with somatostatin analogues should be performed for further diagnosis.

Correlation of four-phase CT findings of rectal neuroendocrine neoplasms with different World Health Organization grades

PURPOSE

To investigate the four-phase computed tomography (CT) features of rectal neuroendocrine neoplasms (R-NENs) as they relate to different World Health Organization pathological grades.

METHODS

A total of 42 patients who underwent pre-operative four-phase CT for evaluation of neoplasms confirmed as different pathological grades of R-NENs by surgery were included. The CT features were retrospectively analyzed by two radiologists in consensus including the tumor location, shape, long diameter, necrosis, boundary, transmural invasion, CT attenuation values of noncontrast and different enhancement phases, intra mesenteric metastasis, lateral lymph node metastasis, and distant metastasis. The differences among R-NENs of different pathological grades were analyzed using T-test, analysis of variance, and non-parametric rank sum test.

RESULTS

Among 42 cases (23 males, 19 females, aged 57 ± 10.48 years) of R-NENs, neuroendocrine tumors G1, G2, and G3 (NET G1, NET G2, NET G3) and neuroendocrine carcinoma (NEC) were 13, 13, 3 and 13 cases, respectively. There were statistically significant differences in tumor long diameter, shape, necrosis, boundary, transmural invasion, CT values in delayed phase, intra mesenteric metastasis, lateral lymph node metastasis, and liver metastasis of different pathological grades (P < 0.001, P = 0.014, P = 0.004, P < 0.001, P < 0.001, P = 0.038, P = 0.006, P = 0.022, and P = 0.020, respectively).

CONCLUSION

Features on four-phase CT can correlate with WHO pathological grades of R-NENs; this may be helpful for preoperative diagnosis and prognosis evaluation.

Recent Advances in the Diagnosis and Management of Carcinoid Syndrome

Carcinoid syndrome, a paraneoplastic condition linked with the release of multiple humoral factors, affects around 30-40% of patients with well-differentiated neuroendocrine tumours. Carcinoid syndrome has a major and unfavourable impact on patients' quality of life; it raises costs when compared to non-functioning neuroendocrine tumours; and it causes patients' lifestyles to alter, such as food, job, physical activity, and social life. Somatostatin analogues have been the first-line therapy for individuals with neuroendocrine tumours and carcinoid disease for decades. While these drugs give considerable relief from carcinoid syndrome symptoms, clinical progression is unavoidable, necessitating further research into newer treatment measures. Carcinoid tumours are sometimes difficult to diagnose because of their vague or nonspecific symptoms. There have been several advancements in all aspects of carcinoid syndrome, as well as novel therapeutics, in the previous few years. New epidemiological studies show that it is becoming more common; increasing insights into the pathogenesis of its various clinical manifestations and its natural history: definition of prognostic factors; new methods to verify its presence; the development of new drugs to treat its various manifestations, both initially and in somatostatin-refractory cases; and an increased understanding of the pathogenesis, natural history, and management of the disease. An all language literature search was conducted on MEDLINE, COCHRANE, EMBASE, and Google Scholar till November 2021. The following search strings and Medical Subject Headings (MeSH) terms were used: "Recent advances", "Carcinoid syndrome", "Neuroendocrine Neoplasms" and "Carcinoid heart disease". We comprehensively reviewed the literature on the pathogenesis, clinical features, and newer treatment modalities for Carcinoid Syndrome. Recent advancements in research and management have resulted from advances in our understanding of the aetiology of carcinoid syndrome. The development of molecular indicators of aggressiveness improved serum tumour markers, and the molecular aetiology of carcinoid heart disease are all possible because of advances in molecular biology. We conducted a comprehensive review to update knowledge regarding the pathophysiology, diagnostic protocols, and current and newer treatments for carcinoid syndrome, which presently requires a multidisciplinary approach, due to the complexity of the illness's aetiology, diagnosis, and therapy.

Imaging neuroendocrine tumors: Characterizing the spectrum of radiographic findings

Neuroendocrine tumors (NET) are a group of neoplasms with neuroendocrine differentiation affecting a wide range of organs. Functional NETs present with symptoms due to the particular hormone produced. Functional NETs are usually small at diagnosis and therefore can be challenging to diagnose. In contrast, non-functioning NETs are generally larger and present with mass effect. Imaging plays an indispensable role in diagnosis, staging and management of patients with NETs. The optimal modality and technique for imaging of NETs depend on the location of primary and metastatic lesions. Regardless of the imaging modality, dynamic contrast-enhanced imaging is essential for evaluation of NETs. In general, CT scan is typically the primary imaging modality for evaluating NETs. MRI is used as a complementary modality, being superior to other modalities to assess liver metastasis. Nuclear medicine imaging is also widely used in NET assessment.

Pancreatic neuroendocrine tumours: spectrum of imaging findings

Pancreatic neuroendocrine tumours (pNETs) are rare and heterogeneous group of neoplasms presenting with a wide variety of symptoms and biological behaviour, from indolent to aggressive ones. pNETs are stratified into functional or non-functional, because of their ability to produce metabolically active hormones. pNETs can be an isolate phenomenon or a part of a hereditary syndrome like von Hippel-Lindau syndrome or neurofibromatosis-1. The incidence has increased in the last years, also because of the improvement of cross-sectional imaging. Computed tomography (CT), magnetic resonance imaging (MRI) and functional imaging are the mainstay imaging modalities used for tumour detection and disease extension assessment, due to easy availability and better contrast/spatial resolution. Radiological imaging plays a fundamental role in detection, characterization and surveillance of pNETs and is involved in almost every stage of patients' management. Moreover, with specific indications and techniques, interventional radiology can also play a role in therapeutic management. Surgery is the treatment of choice, consisting of either partial pancreatectomy or enucleation of the primary tumour. This article reviews the radiologic features of different pNETs as well as imaging mimics, in order to help radiologists to avoid potential pitfalls, to reach the correct diagnosis and to support the multidisciplinary team in establishing the right treatment.

Multimodality Imaging of Neuroendocrine Tumors

Neuroendocrine tumors are rare solid tumors with an estimated 12,000 people in the United States diagnosed each year. Neuroendocrine tumors can occur in any part of the body. There is a wide spectrum of disease, ranging from slow-growing and indolent tumors found incidentally to highly aggressive malignancies with a poor prognosis. Knowledge of neuroendocrine tumor pathology is essential in the diagnostic workup of these patients. This article focuses on the evaluation, detection, and staging of common neuroendocrine tumors with multiple imaging modalities; the information gained with a multimodality approach is often complementary and leads to image-guided treatment decision making.

Understanding the Lymphatics: Review of the N Category in the Updated TNM Staging of Cancers of the Digestive System

OBJECTIVE. The N category has been significantly updated in the 8th edition of the American Joint Committee on Cancer's TNM classification. To ensure correct tumor staging, prognosis, and management, it is critical to be aware of these changes. This article reviews the updated N category, organ-specific regional lymph nodes, and lymphatic drainage pathways for cancers of the digestive system from the esophagus to the anal canal. CONCLUSION. Detection of lymph node involvement may be challenging, and knowledge of nodal characteristics, lymphatic drainage pathways, and imaging modalities is essential to optimize detection rate to ensure accurate staging, prognosis estimation, and streamlined management.

CT- and ultrasound-characteristics of hepatic lesions in patients with multiple endocrine neoplasia syndrome. A retrospective image review of 25 cases

Introduction

Liver metastases from neuroendocrine tumors in multiple endocrine neoplasia syndrome are common (75%) and significantly impairs the prognosis. Characterisation of liver lesions in these patients is challenging, as liver metastases are difficult to differentiate from benign liver lesions such as haemangioma.

Methods

In this study we aimed to characterize the radiological findings of hepatic metastases in MEN patients. The findings of contrast-enhanced CT were considered for the main diagnosis. We retrospectively evaluated 25 patients with MEN-syndrome (10 MEN1/ 15 MEN2) including 11 men and 14 women between 28–62 years of age.

Results

Liver metastases (48%, 12/25) and hemangioma (40%, 10/25) were the most common liver lesions among our patients. The most common primary tumors in our MEN1 and MEN2 patients with liver metastases were of pancreatic neuroendocrine tumor (70%, 7/10) und medullary thyroid carcinoma (100%, 15/15) origin, respectively. CT-characteristics were grouped into three main categories, depending on contrast dynamics. The majority of hepatic metastases (75%, 14/25) are presented as multiple lesions with a slow growth in an average 5 years of follow-up-period. We were able to find a common CT pattern and categorise these for each MEN-syndrome. Hepatic metastases in MEN1 presented commonly a blurred arterial enhancement with a low portal venous enhancement and less frequently a prominent enhancement in the arterial phase, which mimics the classical haemangioma. In MEN2 the liver metastases exhibited disseminated mixed hyper- and hypo-enhanced lesions in CT-scans. Moreover, lesion calcifications are pathognomonic in MEN2. The main limitation of this study is the missing histopathological confirmation in the majority of cases.

Conclusions

In this retrospective imaging study, we were able to categorise and find a common CT pattern for hepatic lesions in patients with MEN-syndrome. In order to differentiate these lesions sufficiently, a combination of a 3-phasic CT-scan with US is required. Other liver specific imaging modalities (MRI, CEUS, SMS-PET/CT) should complement the diagnosis in individual cases.

Imaging presentation of pancreatic neuroendocrine neoplasms

Abstract

Pancreatic neuroendocrine neoplasms (P-NENs) are the second most common solid pancreatic neoplasms. P-NENs have a wide range of imaging features presentations and they can be detected with typical and atypical imaging presentations. Typical and atypical appearances can be explained by pathologic correlations. P-NENs are generally hypervascular lesions, showing a typical enhancement behavior after contrast media injection during imaging methods, but they could also have different imaging features, creating some difficulty in differential diagnosis. For this reason, radiologists should be aware of different imaging presentations of these neoplasms. Radiological evaluation has a critical role in P-NENs identification, characterization, and staging of these neoplasms, especially in those cases in which surgery is the treatment of choice. The present paper shows, indicating the underlying pathologic correlations, typical and atypical presentations of NENs.

Key Points

• P-NENs have a wide range of imaging features presentations, typical and atypical.

• Pathology could help in better understanding the typical P-NENs appearance at imaging.

• P-NENs are generally hypervascular lesions.

• Radiological evaluation has a critical role in P-NENs identification and management.

• Radiologists should know every type of different imaging presentation of P-NENs to better diagnose these kinds of lesions.

Diagnostic imaging of gastrointestinal neuroendocrine tumours (GI-NETs): relationship between MDCT features and 2010 WHO classification

AIMS

We aimed to present our series of gastrointestinal neuroendocrine tumours (GI-NETs) in order to illustrate and highlight the associated contrast-enhanced multi-detector computed tomography (MDCT) features. We also attempted to identify a relationship between MDCT imaging and the 2010 World Health Organization (WHO) classification system.

MATERIALS AND METHODS

We selected all patients with pathologically proven GI-NETs diagnosed between January 2010 and August 2017. Only patients undergone contrast-enhanced MDCT imaging in the immediate preoperative period were included in our study. Later, two expert radiologists retrospectively assessed MDCT intestinal and extra-intestinal signs. We also analysed the relationship between MDCT imaging and the 2010 WHO classification.

RESULTS

A total of 20 patients (13 males, 7 females, age range 37-89 years, mean age 69.9 years) were included in our study. The majority of GI-NETs (85%) occurred in the small bowel and mainly in the terminal ileum. Forty-five percentage of our GI-NETs were diagnosed after an access to emergency medical service for obstruction symptoms or gastrointestinal bleeding. Regarding intestinal signs, 15/20 patients showed an intraluminal nodular mass and 5/20 a wall thickening. Extra-intestinal signs were present in 75% of cases. Desmoplastic reaction and lymph nodes metastases were significantly correlated with higher grade of GI-NETs.

CONCLUSIONS

The majority of GI-NETs appears as intraluminal mass often associated with extra-intestinal signs. We found a significantly correlation between higher grade of GI-NETs and extra-intestinal signs. MDCT imaging may be useful in predicting the pathological classification of GI-NETs.

Primary hepatic neuroendocrine neoplasm: Long-time surgical outcome and prognosis

Primary hepatic neuroendocrine neoplasms (PHNENs) represent a kind of rare liver tumor and its clinical features and prognosis remain unclear. This study aims to reveal the long-term therapeutic outcome of PHNEN and to present its prognostic feature.A retrospective designed, single-center study containing 22 patients with PHNENs receiving surgical resections was done. Clinical data were reviewed and long-term follow-up was updated. Survival analysis was tried to find the prognostic factors.Nine patients recurred (recurrence rate = 40.9%) and 6 patients died on the disease. The actual 1-, 3-, and 5-year recurrence-free survival rate were 86.4%, 63.6%, and 52.9%, respectively. The 1-, 3-, and 5-year overall survival rate were 95.5%, 81.8%, and 64.7%, respectively. Median overall survival for group G1, G2, and G3 were 69, 67, and 42 months, respectively.Patients with PHNEN can have a long survival after radical surgical resection, especially when the tumor proliferative grade exhibits lower (G1/2).

CT perfusion in normal liver and liver metastases from neuroendocrine tumors treated with targeted antivascular agents

OBJECTIVE

To assess the effects of bevacizumab and everolimus, individually and combined, on CT perfusion (CTp) parameters in liver metastases from neuroendocrine tumors (mNET) and normal liver.

METHODS

This retrospective study comprised 27 evaluable patients with mNETs who had participated in a two-arm randomized clinical trial of mono-therapy with bevacizumab (Arm B) or everolimus (Arm E) for 3 weeks, followed by combination of both targeted agents. CTp was undertaken at baseline, 3 and 9 weeks, to evaluate blood flow (BF), blood volume (BV), mean transit time (MTT), permeability surface area product (PS), and hepatic arterial fraction (HAF) of mNET and normal liver, using a dual-input distributed parameter physiological model. Linear mixed models were used to estimate and compare CTp parameter values between time-points.

RESULTS

In tumor, mono-therapy with bevacizumab significantly reduced BV (p = 0.05); everolimus had no effects on CTp parameters. Following dual-therapy, BV and BF were significantly lower than baseline in both arms (p ≤ 0.04), and PS was significantly lower in Arm E (p < 0.0001). In normal liver, mono-therapy with either agent had no significant effects on CTp parameters: dual-therapy significantly reduced BV, MTT, and PS, and increased HAF, relative to baseline in Arm E (p ≤ 0.04); in Arm B, only PS reduced (p = 0.04).

CONCLUSIONS

Bevacizumab and everolimus, individually and when combined, have significant and differential effects on CTp parameters in mNETs and normal liver, which is evident soon after starting therapy. CTp may offer an early non-invasive means to investigate the effects of drugs in tumor and normal tissue.

Primary hepatic neuroendocrine carcinoma: report of two cases and literature review

Background

Primary hepatic neuroendocrine carcinoma (PHNEC) is extremely rare. The diagnosis of PHNEC remains challenging—partly due to its rarity, and partly due to its lack of unique clinical features. Available treatment options for PHNEC include surgical resection of the liver tumor(s), radiotherapy, liver transplant, transcatheter arterial chemoembolization (TACE), and administration of somatostatin analogues.

Case presentation

We report two male PHNEC cases and discuss the diagnosis and treatment options. Both cases presented with abdominal pain; case two also presented with symptoms of jaundice. The initial diagnosis for both cases was poorly differentiated grade 3 small-cell neuroendocrine carcinoma, based on imaging characteristics and the pathology of liver biopsies. Final diagnoses of PHNEC were arrived at by ruling out non-hepatic origins. Case one presented with a large tumor in the right liver lobe, and the patient was treated with TACE. Case two presented with tumors in both liver lobes, invasions into the left branch of hepatic portal vein, and metastasis in the hepatic hilar lymph node. This patient was ineligible for TACE and was allergic to the somatostatin analogue octreotide. This limited treatment options to supportive therapies such as albumin supplementation for liver protection. Patient one and two died at 61 and 109 days, respectively, following initial hospital admission.

Conclusions

We diagnosed both cases with poorly differentiated grade 3 small-cell PHNEC through imaging characteristics, immunohistochemical staining of liver biopsies, and examinations to eliminate non-hepatic origins. Neither TACE nor liver protection appeared to significantly extend survival time of the two patients, suggesting these treatments may be inadequate to improve survival of patients with poorly differentiated grade 3 small-cell PHNEC. The prognosis of poorly differentiated grade 3 small-cell PHNEC is poor due to limited and ineffective treatment options.

Electronic supplementary material

The online version of this article (10.1186/s12907-018-0070-7) contains supplementary material, which is available to authorized users.

Primary hepatic neuroendocrine tumors: multi-modal imaging features with pathological correlations

BACKGROUND

Primary hepatic neuroendocrine carcinomas (PHNECs) are rare and asymptomatic, and are therefore difficult to distinguish radiologically from other liver carcinomas. In this study, we aimed to determine the computed tomography (CT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) features of PHNECs.

METHODS

A retrospective analysis of 11 patients with pathologically proven PHNECs was performed from January 2009 to September 2014. The CT, MRI, and DSA image features were analysed.

RESULTS

Ten of the eleven patients exhibited two or more lesions, and one patient exhibited a single lesion. Abdominal CT of 8 cases revealed multiple round or oval-shaped masses with well-defined borders, which were heterogeneous and hypodense on precontrast CT images. Significant diffuse heterogeneous enhancement was observed during the arterial phase in 8 cases, and the enhancement was slightly higher than the attenuation of the surrounding normal liver parenchyma and indistinct edges of small lesions during the portal phase. Well circumscribed (11 cases), lobulated (5 cases) or multiple nodular masses (4 cases), nodule (1 case) and irregular masses (1 case) of high signal intensity were observed on T2WI and DWI of MR images. The masses were well circumscribed, heterogeneous, and hypointense on T1WI, with significant enhancement of the solid carcinoma portion in the early arterial phase and continued enhancement in the portal venous phase. Characteristic lobulated or multiple nodular masses were observed in MRI. DSA showed multiple hypervascular carcinoma-staining lesions with sharp edges in the arterial phase.

CONCLUSION

The CT, MRI, and DSA images of PHNECs exhibit specific characteristic features. Appropriate combinations of the available imaging modalities could therefore optimize the evaluation of patients with PHNECs.

State-of-the-art Imaging of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors are rare tumors that present many imaging challenges, from detecting small functional tumors to fully staging large nonfunctioning tumors, including identifying all sites of metastatic disease, particularly nodal and hepatic, and depicting vascular involvement. The correct choice of imaging modality requires knowledge of the tumor type (eg, gastrinoma versus insulinoma), and also the histology (well vs poorly differentiated). Evolving techniques in computed tomography (CT), MRI, endoscopic ultrasonography, and nuclear medicine, such as dual-energy CT, diffusion-weighted MRI, liver-specific magnetic resonance contrast agents, and new nuclear medicine agents, offer new ways to visualize, and ultimately manage, these tumors.

Contrast-enhanced ultrasound of pancreatic tumours

Indication/purpose: To review contrast‐enhanced ultrasound features of the most common pancreatic tumours.

Methods: Contrast‐enhanced ultrasound (CEUS) can provide distinctive features of pancreatic tumours that are reported in the present paper, providing radiologic‐pathological correlations and clarifying the main differential diagnosis.

Conclusion: Contrast‐enhanced ultrasound plays a well‐established role in the evaluation of pancreatic tumours. When possible, CEUS should be always performed after the initial US diagnosis, in order to improve the accuracy of the first line examination.

Small Bowel Carcinoids: A Single Surgeon's Experience in Southern India

INTRODUCTION

Small bowel carcinoid tumours are indolent neuroendocrine tumours usually seen in the 6(th) and 7(th) decades. Most often, they are silent with non-specific symptoms. They generate serotonin, provoking a desmoplastic reaction in the mesentery leading to bowel ischemia and obstruction. While CECT abdomen can help raise suspicion and show regional spread, elevated 24-hour urinary 5-HIAA levels, histopathology and immunohistochemistry for Chromogranin A are confirmatory.

AIM

To analyse a single surgeon's experience of clinical features and diagnosis of carcinoid tumours of the small intestine.

SETTING AND DESIGN

Retrospective study conducted at MS Ramaiah Medical College and Hospital, Bangalore, India.

MATERIALS AND METHODS

Fourteen cases of carcinoid of the small bowel presenting to our institution over a 9-year period between December 2005 and November 2014 comprised the study. This included 10 males to 4 females aged 43 to 67 years (Mean: 54.4 years). The patients were investigated using x-ray abdomen, barium study, CECT abdomen, colonoscopy and 24-hour urinary 5- HIAA levels. All patients were surgically treated and histological examination of the resected tumours and immunohistochemistry for Chromogranin A was performed.

RESULTS

Twelve patients with ileal carcinoids presented with long standing intestinal colic and sub-acute obstruction. Two patients with jejunal carcinoids had epigastric pain. X-ray abdomen was suggestive of small bowel obstruction in 12 patients. CECT abdomen done in 6 patients, showed ileal narrowing causing proximal dilatation; and cocooining of ileal loops at ileo-caecal junction in 2 cases. Ten patients underwent segmental resection-anastomosis of the tumour-bearing intestine while 4 patients underwent a right hemicolectomy. Lymph node spread was seen in 8 patients of whom 4 had liver metastases. Histopathology and Chromogranin A positivity confirmed the diagnoses. Postoperatively, 24-hour urinary 5-HIAA was mildly elevated in 2 patients. 12 patients were disease free at mean follow up of 4.3 years. 2 patients died due to inanition at 3 and 5 months postoperatively.

CONCLUSION

Carcinoid tumours of small intestine are uncommon in southern India. But they should be considered as differential diagnosis when intestinal tuberculosis is suspected in the elderly presenting with intestinal colic or sub-acute obstruction. They are associated with good prognosis after adequate resection.

Imaging of pancreatic neoplasms

Ductal adenocarcinoma accounts for 85% to 90% of all solid pancreatic neoplasms, is increasing in incidence, and is the fourth leading cause of cancer-related deaths. There are currently no screening tests available for the detection of ductal adenocarcinoma. The only chance for cure in pancreatic adenocarcinoma is surgery. Imaging has a crucial role in the identification of the primary tumor, vascular variants, identification of metastases, disease response assessment to treatment, and prediction of respectability. Pancreatic neuroendocrine neoplasms can have a distinctive appearance and pattern of spread, which should be recognized on imaging for appropriate management of these patients.

[Gastroenteropancreatic endocrine tumors]

CLINICAL/METHODICAL ISSUE

Gastroenteropancreatic neuroendocrine tumors (GEP-NET) are a rare, heterogeneous group of neoplasms. Only 2% of gastrointestinal tumors belong to the group of neuroendocrine neoplasms.

STANDARD RADIOLOGICAL METHODS

A wide spectrum of diagnostic imaging modalities is available: apart from ultrasound not only computed tomography (CT) but also magnetic resonance imaging (MRI) and positron emission tomography CT (PET-CT) play an important role in detection and staging of GEP-NETs.

METHODICAL INNOVATIONS

The PET-CT technique with somatostatin analogues is used for staging as well as for evaluation and monitoring of treatment with peptide radionuclide radiation therapy.

PERFORMANCE

According to the literature NETs of the small bowel with a size over 3 cm can be detected with a sensitivity of 84.7% and a specificity of 96.6% using CT enteroclysis and MR enteroclysis provides the detection of NETs of the small bowel in 93.3% of cases. 'The sensitivity of MRI in detection of pancreatic NETs is between 74% and 100% and is, therefore, higher than CT. Detection of small primary tumors is carried out using PET-CT and seems to be the most sensitive imaging modality to identify the exact location. On the other hand MRI has to be regarded as the best imaging modality for detection of liver metastases compared to CT and PET-CT.

ACHIEVEMENTS

The role of diagnostic imaging is to identify the exact location of the primary tumor and possible metastases, to define an appropriate therapy and to monitor treatment effects; however, the choice of the most appropriate diagnostic imaging modality varies depending on the location and type of the primary tumor.

PRACTICAL RECOMMENDATIONS

The GEP-NETs are predominantly well-vascularized; therefore, dual-phase CT/MR imaging with the arterial and venous phases after contrast media injection is mandatory for detection and localization of primary tumors and metastases. For whole body staging CT and PET-CT should be performed.

Primary hepatic neuroendocrine tumor with multiple liver metastases: A case report with review of the literature

We herein present a case involving a 41-year-old woman in whom ultrasound examination revealed multiple liver hemangiomas more than 3 years ago. Follow-up ultrasound examination revealed that the masses had significantly increased; the largest was located in the right lobe (about 8.2 cm × 7.4 cm × 6.0 cm). Abdominal multidetector computed tomography revealed multiple well-circumscribed, heterogeneous, hypodense masses (largest, 6.4 cm × 6.3 cm × 5.0 cm) with significant contrast enhancement during the arterial and portal phases and with contrast wash-out and peripheral enhancement during the delayed phases. Magnetic resonance images demonstrated multiple well-circumscribed, heterogeneous, hypointense hepatic masses with significant contrast enhancement (largest, 6.4 cm × 6.5 cm × 5.1 cm); multiple enlarged porta lymph nodes; and multiple slightly enlarged retroperitoneal lymph nodes. Histological and immunohistochemical examination of the right mass biopsy specimen suggested a malignant neoplasm that had originated from a neuroendocrine cell type (grade 2 well-differentiated neuroendocrine carcinoma). After performing a systemic examination to exclude metastasis from an extrahepatic primary site, we considered that the masses had arisen from a primary hepatic neuroendocrine tumor with multiple liver metastases. The patient underwent transcatheter arterial chemoembolization using a combination of oxaliplatin (150 mg) mixed with one bottle of gelatin sponge particles (560-710 μm) and lipiodol (6 mL). Primary neuroendocrine tumors of the liver are extremely rare. This case is interesting because of the rarity of this neoplasm and previous misdiagnosis as multiple liver hemangiomas. Previously reported cases in the literature are also reviewed.

Clinical characteristics and prognosis of primary pancreatic carcinoid tumors: A report of 13 cases from a single institution

The present study aimed to analyze the diagnosis and treatment of 13 cases of pancreatic carcinoid tumors during a 56-year period at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China). The data from 13 cases, consisting of 5 males and 8 females (mean age, 50 years), were collected and analyzed. Hematoxylin-eosin and immunohistochemistry staining were performed to investigate the expression of neuron-specific enolase (NSE), cytokeratin (CK), chromogranin A (CgA) and synaptophysin (Syn) in the tumors. The affected patients suffered abdominal and/or back pain without typical carcinoid syndrome. Radical resection was performed in 10 cases and regional resection in one case. The remaining two patients exhbited remote metastasis, and so were treated with single and double bypass surgery (choledochojejunostomy and gastrojejunostomy/choledochojejunostomy, respectively). The expression of CK, Syn, CgA and NSE was positive in nine (69.23%), 10 (76.92%), five (38.46%) and eight (61.54%) cases, respectively. The median survival time was 26.6 months. In conclusion, in patients with pancreatic carcinoid tumors that exhibit no typical carcinoid syndrome, such as those in the present study, the diagnosis can be confirmed by pathological examination and surgery is the most effective treatment.

Laparoscopic resection of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are a rare heterogeneous group of endocrine neoplasms. Surgery remains the best curative option for this type of tumor. Over the past two decades, with the development of laparoscopic pancreatic surgery, an increasingly larger number of PNET resections are being performed by these minimally-invasive techniques. In this review article, the various laparoscopic surgical options for the excision of PNETs are discussed. In addition, a summary of the literature describing the outcome of these treatment modalities is presented.

Iodine-131MIBG SPECT/CT in neuroendocrine tumours: An institutional experience

Context:

Radiolabelled metaiodobenzylguanidine (MIBG) is commonly used for imaging of neuroendocrine tumors (NETs). The hybrid imaging with single photon emission computerized tomography/computerized tomography (SPECT/CT) co-registration can give that additional edge to this functional imaging modality.

Aims:

To study the additional value of ¹³¹I-MIBG SPECT/CT scintigraphy in evaluation of NETs.

Settings and Design:

We performed a retrospective study of the scintigraphic data of patients referred to our department for detection and follow-up of NETs from 2004 to 2008.

Materials and Methods:

Total number of studies were 370. Twenty-eight patients with equivocal findings on planar imaging had undergone additional SPECT/CT imaging. The contribution made by SPECT/CT imaging in these studies was analyzed.

Results:

In 27 of 28 cases, SPECT/CT provided vital additional information.

Conclusions:

We concluded that SPECT/CT co-registration helps in exclusion, identification, and localization of primary and metastatic NETs. It differentiates physiological from pathological tracer distribution. It helps increase the confidence in reporting, especially in equivocal findings on planar imaging.

Pancreatic neuroendocrine neoplasms: diagnosis and management

Pancreatic neuroendocrine neoplasms are uncommon but rising in incidence. There have been recent changes in the WHO nomenclature and a newly proposed American Joint Committee on Cancer TNM staging, which complement each other. These neoplasms are of great medical and radiological interest because of their diverse presenting features and imaging appearances. There is an increased role for both anatomic and functional imaging in the assessment of these neoplasms. A review of the nomenclature, staging, and imaging is presented in this paper.

Incidental neuroendocrine tumors of the pancreas: MDCT findings and features of malignancy

OBJECTIVE

The objective of our study was to evaluate the MDCT features of incidentally detected neuroendocrine tumors (NETs) of the pancreas, identify features that can predict tumor biology or aggressiveness and long-term outcome, and determine the incidence of "nonbenign" behavior.

MATERIALS AND METHODS

In this retrospective study, 60 histologically verified pancreatic NETs incidentally detected with contrast-enhanced MDCT were included. Various MDCT features such as size, morphology, enhancement, and presence of calcifications were evaluated and were correlated with tumor biology on histopathology. The sensitivity, specificity, predictive values, and accuracy were calculated for MDCT features in predicting nonbenign biology and risk of recurrence.

RESULTS

A total of 32 of 60 (53%) NETs were nonbenign: most were large (mean, 29.1 mm) with a solid or complex pattern. NET size of 3 cm or larger yielded a positive predictive value of 61% for nonbenign tumors and 100% when calcification was present. In 12 patients with recurrence, 92% of NETs were nonbenign. The presence of calcification, local invasion, main pancreatic duct dilatation, vascular invasion, and lymph node enlargement along with angioinvasion and a Ki-67 index greater than 2% on histology were associated with a nonbenign diagnosis and a higher risk of recurrence.

CONCLUSION

Approximately 50% of incidental NETs show uncertain or malignant behavior. Solid tumors 3 cm or larger are commonly nonbenign; however, about 30% of tumors smaller than that size cutoff can be malignant. Nonbenign tumors and those with invasive features on MDCT have a higher incidence of recurrence.

Gastroenteropancreatic neuroendocrine tumors: role of imaging in diagnosis and management

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of neoplasms that arise from cells of the diffuse neuroendocrine system and are characterized by a wide spectrum of clinical manifestations. All NETs are potentially malignant but differ in their biologic characteristics and the probability of metastatic disease. The pathologic classification of these tumors relies on their proliferation and differentiation. In the past decades, several nomenclatures have been proposed to stratify neuroendocrine tumors, but the World Health Organization classification is the one that is most widely accepted and used. The diagnosis of neuroendocrine tumor relies on clinical manifestation, laboratory parameters, imaging features, and tissue biomarkers in a biopsy specimen. With improved understanding of the natural history and lesion biology, management of GEP-NETs has also evolved. Although surgery remains the only potentially curative therapy for patients with primary GEP-NETs, other available treatments include chemotherapy, interferon, somatostatin analogs, and targeted therapies. Recent improvements in both morphologic and functional imaging methods have contributed immensely to patient care. Morphologic imaging with contrast agent-enhanced multidetector computed tomography and magnetic resonance imaging is most widely used for initial evaluation and staging of disease in these patients, whereas functional imaging techniques are useful both for detection and prognostic evaluation and can change treatment planning.

Simultaneous EUS-FNA Diagnosis and TNM Staging of a Pancreatic Neuroendocrine Tumor in a Patient with an Unrecognized MEN Type 1

We report the case of a woman who, during oncological followup for bronchial carcinoid (diagnosed in 2005), papillary thyroid carcinoma, and bilateral parathyroid adenoma (simultaneously diagnosed in 2007), performed a pancreatic endoscopic ultrasonography with fine needle agobiopsy (EUS-FNA) for a positron emission tomography (PET) suspicion of pancreatic and hepatic lesions; during the procedure, the pancreatic and liver lesions were confirmed, and a peripancreatic lymph node involvement was found, allowing a complete pTNM staging during the same procedure.

Utility of ¹¹¹indium-pentetreotide scintigraphy in patients with neuroendocrine tumors

BACKGROUND

Neuroendocrine (NE) tumors pose a diagnostic challenge with the need to utilize a combination of biochemical analysis, standard cross-sectional imaging, and more recently, nuclear medicine scans such as (111)indium-pentetreotide scintigraphy (somatostatin receptor scintigraphy, SRS; OctreoScan, Covidien Imaging Solutions, Hazelwood, MO). In this study we sought to evaluate the clinical utility of scintigraphy in the diagnosis and management of patients with NE tumors at a major university hospital.

METHODS

A retrospective chart review was performed on all patients who underwent both (111)indium-pentetreotide scintigraphy and computed tomography/magnetic resonance imaging (CT/MRI) at a single institution between February 2001 and July 2008. Charts were reviewed for patient demographics, symptoms of NE disease, and results of biochemical testing, imaging studies, histopathologic diagnosis, and medical and/or surgical management.

RESULTS

One hundred forty-five patients received (111)indium-pentetreotide scintigraphy (SRS) and concurrent cross-sectional imaging (CT/MRI) over the 7-year period studied. In the evaluation of primary disease, 60 % of tumors were localized by anatomic imaging, significantly greater than the 15 % detection rate achieved by SRS. In the evaluation of recurrent disease, 61 % of NE tumors were localized by cross-sectional imaging, significantly greater than the 31 % detection rate of SRS. Scintigraphy identified disease foci not seen on CT/MRI in just 8 of 74 of the cohort with evidence of disease and only altered the surgical management in 3 of 74 cases.

CONCLUSIONS

Cross-sectional CT/MRI imaging is sufficient for the localization of NE tumors. (111)Indium-pentetreotide scintigraphy does not significantly alter the surgical management of patients with NE tumors, and we suggest that it be selectively reserved for patients with disease that is occult to cross-sectional imaging.

Endoscopic ultrasound in gastroenteropancreatic neuroendocrine tumors

Endoscopic ultrasound (EUS) is an advanced endoscopic technique currently used in the staging and diagnosis of many gastrointestinal neoplasms. The proximity of the echoendoscope to the gastrointestinal tract lends itself to a detailed view of the luminal pathology and the pancreas. This unique ability enables endoscopists to use EUS in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Diagnostic EUS allows previously unidentified NETs to be localized. EUS also determines tumor management by staging the GEP-NETS, enabling the clinicians to choose the appropriate endoscopic or surgical management. The ability to obtain a tissue diagnosis with EUS guidance enables disease confirmation. Finally, recent developments suggest that EUS may be used to deliver therapeutic agents for the treatment of NETs. This review will highlight the advances in our knowledge of EUS in the clinical management of these tumors.

Neuroendocrine tumors of the pancreas

PURPOSE OF REVIEW

Pancreatic neuroendocrine tumors (PNETs) are rare tumors, with an incidence of one per 100, 000 individuals per year, and they account for 1-2% of all pancreatic neoplasms. PNETs are a heterogeneous group with varying clinical presentation, tumor biology and prognosis. This article reviews the current diagnostic strategy and treatment armamentarium for PNETs. Special attention is paid to recent and ongoing developments in treatment, particularly with regards to multimodality treatment and newer systemic therapies for unresectable disease.

RECENT FINDINGS

There has been significant progress in the genetic understanding of hereditary syndromes in regards to PNETs, as well as in the diagnosis and treatment of resectable and nonresectable PNETs. Whereas surgical therapy remains the most advisable therapy for resectable neuroendocrine tumors of the pancreas, there have been significant recent advances in systemic therapy for those with unresectable disease. Results from recent clinical trials examining mammalian target of rapamycin inhibitors and tyrosine kinase inhibitors for unresectable disease are promising in expanding treatment options for metastatic PNETs.

SUMMARY

Neuroendocrine tumors of the pancreas are a heterogeneous group of tumors with varying clinical presentation, tumor biology and prognosis. Clinicians must be aware of the variety of manifestations of this disease, as well as the role of systemic chemotherapy in treatment of unresectable disease.

Carcinoid tumor with bilateral renal involvement in a child

Carcinoid tumors are uncommon in children. Kidneys are rarely involved as they do not possess neuro-endocrine cells. Work up of painless hematuria after abdominal trauma in a 10-year-old boy revealed primary carcinoid tumors with metastasis to both kidneys. We were unable to find any previous reports of renal involvement by carcinoid tumor in children.

Nuclear medicine techniques for the imaging and treatment of neuroendocrine tumours

Nuclear medicine plays a pivotal role in the imaging and treatment of neuroendocrine tumours (NETs). Somatostatin receptor scintigraphy (SRS) with [(111)In-DTPA(0)]octreotide has proven its role in the diagnosis and staging of gastroenteropancreatic NETs (GEP-NETs). New techniques in somatostatin receptor imaging include the use of different radiolabelled somatostatin analogues with higher affinity and different affinity profiles to the somatostatin receptor subtypes. Most of these analogues can also be labelled with positron-emitting radionuclides that are being used in positron emission tomography imaging. The latter imaging modality, especially in the combination with computed tomography, is of interest because of encouraging results in terms of improved imaging quality and detection capabilities. Considerable advances have been made in the imaging of NETs, but to find the ideal imaging method with increased sensitivity and better topographic localisation of the primary and metastatic disease remains the ultimate goal of research. This review provides an overview of the currently used imaging modalities and ongoing developments in the imaging of NETs, with the emphasis on nuclear medicine and puts them in perspective of clinical practice. The advantage of SRS over other imaging modalities in GEP-NETs is that it can be used to select patients with sufficient uptake for treatment with radiolabelled somatostatin analogues. Peptide receptor radionuclide therapy (PRRT) is a promising new tool in the management of patients with inoperable or metastasised NETs as it can induce symptomatic improvement with all Indium-111, Yttrium-90 or Lutetium-177-labelled somatostatin analogues. The results that were obtained with [(90)Y-DOTA(0),Tyr(3)]octreotide and [(177)Lu-DOTA(0),Tyr(3)]octreotate are even more encouraging in terms of objective tumour responses with tumour regression and documented prolonged time to progression. In the largest group of patients receiving PRRT, treated with [(177)Lu-DOTA(0),Tyr(3)]octreotate, a survival benefit of several years compared with historical controls has been reported.

EUS is still superior to multidetector computerized tomography for detection of pancreatic neuroendocrine tumors

BACKGROUND

The role of EUS for detection of pancreatic neuroendocrine tumors (PNETs) is not clearly defined in institutions that use multidetector CT for pancreatic imaging.

OBJECTIVE

The aims of this study were to (1) compare the detection rates of EUS and CT by type and size of PNET and calculate the incremental benefit of EUS over CT, (2) evaluate the CT detection rate for PNETs adjusted for improved CT technology over time, and (3) determine the factors associated with CT-negative PNETs.

DESIGN

Retrospective single-center cohort study.

SETTING

Johns Hopkins Hospital.

PATIENTS

Patients with pathologically proven PNETs with preoperative CT. Incidentally found PNETs (resection specimens) and those without Johns Hopkins Hospital CT imaging were excluded.

MAIN OUTCOME MEASUREMENT

Detection rates of CT and EUS were compared by using pathology as the reference standard.

RESULTS

In 217 patients (with 231 PNETs) studied, CT detected 84% of tumors (54.3% of insulinomas). The sensitivity of CT for the detection of PNETs significantly increased with improvement in CT technology (P = .02; χ(2) for trend). CT was more likely to miss lesions <2 cm (P = .005) and insulinomas (P < .0001). In 56 patients who had both CT and EUS, the sensitivity of EUS was greater than CT (91.7% vs 63.3%; P = .0002), particularly for insulinomas (84.2% vs 31.6%; P = .001). EUS detected 20 of 22 CT-negative tumors (91%).

LIMITATIONS

Retrospective nonrandomized design and referral bias.

CONCLUSIONS

The detection rate of CT has significantly improved over time. CT-negative tumors are small and more likely to be insulinomas. A sequential approach of CT followed by EUS can detect most PNETs. EUS is a more sensitive initial test for the detection of suspected insulinomas.

Standard imaging techniques for neuroendocrine tumors

Several diagnostic imaging techniques have been used successfully for evaluating patients with neuroendocrine tumors (NETs). These techniques include computed tomography (CT), magnetic resonance imaging, positron emission tomography/CT, single-photon emission CT (SPECT), and SPECT/CT. This article reviews the various imaging methods and their respective advantages and limitations for use in different types of NETs, in particular carcinoid tumors.

Imaging techniques in pancreatic tumors

Conventional ultrasonography represents the first diagnostic imaging modality for the study of pancreatic tumors. Contrast-enhanced ultrasound has significantly improved the accuracy of first-line examination and may influence the choice of second-line investigations: multidetector computed tomography is considered the gold standard for studying pancreatic solid lesions and tumor staging, while MRI with magnetic resonance cholangiopancreatography allows better study of pancreatic cystic lesions and the ductal system. To definitely diagnose a pancreatic lesion, image-guided fine-needle-aspiration or biopsy are very often required. PET with 18-fluorodeoxyglucose, endoscopic ultrasound and intraoperative ultrasonography remain techniques often employed in the third line. This article reviews the imaging techniques generally used for diagnosing the main pancreatic tumors, and a work-up algorithm is finally proposed.

Primary renal carcinoid tumour with inferior vena caval tumour thrombus

Carcinoid tumours, most frequently reported in the gastrointestinal and respiratory tracts, are exceedingly rare primary renal cancers. Few cases have been published to date. To our knowledge, we report the first case of a primary carcinoid tumour of the kidneys involving the inferior vena cava. We treated a 58-year-old woman with an open radical nephrectomy and cavotomy with thrombectomy. We describe the presentation, investigations and pathology results. We discuss the current experience with carcinoid tumours as a literature review relating to the diagnosis of the disease and the prognosis of patients with this neoplasm. Localized carcinoid tumours of the kidneys, including those involving the vena cava, can be successfully treated with surgical excision.

A clinical overview of pheochromocytomas/paragangliomas and carcinoid tumors

Pheochromocytomas/paragangliomas are rare tumors; most are sporadic. Biochemical proof of disease is better with measurement of plasma metanephrines and less cumbersome than determinations in urine; its implementation is expanding. Anatomical imaging with computed tomography or magnetic resonance imaging should be followed by functional (nuclear medicine) imaging: chromaffin tumor-specific methods are preferred. Treatment is surgical; for nonoperable disease other options are available. Overall 5-year survival is 50%. Carcinoid tumors derive from serotonin-producing enterochromaffin cells in the fore-, mid- or hindgut. Biochemical screening (and follow-up) is done with measurements of 5-hydroxyindoloacetic acid in urine. For most carcinoids, functional imaging is better than other modalities in localizing primary tumors. Surgery is the treatment of choice; nonresectable tumors are treated with somatostatin analogs or chemotherapy. Overall 5-year survival for patients with carcinoids is 67%.