Functioning and nonfunctioning neuroendocrine tumors of the pancreas

A Rare Cause of Hypoglycemia in Elderly Patients: Insulinoma

Insulinoma is the most common pancreatic neuroendocrine tumor and is often solitary and benign. To make a diagnosis, high insulin levels must be demonstrated, and proinsulin and C-peptide measurements must be done. The presence of hypoglycemic measurements and symptoms in the 72-hour fasting test is diagnostic. We present a case of a 91-year-old patient with no known diagnosis of diabetes mellitus who was admitted to the emergency department due to confusion. As a result of the clinical evaluation and differential diagnosis, it was determined that her complaint was due to hypoglycemia, and she was admitted to the internal medicine service for further examination, diagnosis, and treatment.

Pancreatic Neuroendocrine Tumor presenting as a diffuse pancreatic enlargement, case report and review of literature

Pancreatic neuroendocrine tumors are rare neoplasms that comprise 1-2% of all pancreatic tumors. However, they are the second most common solid pancreatic neoplasms. They have a wide range of imaging appearances and they can show common to very rare imaging presentations. Most of the time they are solitary well-marginated enhancing solid mass arising in a certain aspect of the pancreas. We present a case report of a 41-year-old female who underwent clinical work-up for abdominal pain, loss of appetite and weight loss for the past year. Ultrasound, computed tomography, and magnetic resonance imaging show diffuse homogenous pancreatic enlargement without contour deformity or a focal mass. Lymphoma and autoimmune pancreatitis were suggested based on imaging findings but IGg4 level and other lab data were normal. Endoscopic ultrasonography confirmed the diffuse enlargement of the pancreas without peripheral structures involvement. The pathological results of multiple fine-needle aspiration biopsy from all parts of the enlarged pancreas revealed a low-grade neuroendocrine tumor.

Pancreatic Ultrasound: State of the Art

An ultrasound (US) study is often the first imaging approach in patients with abdominal symptoms or signs related to abdominal diseases, and it is often part of the routine workup. The pancreatic gland, despite its retroperitoneal site, can be efficiently examined with US thanks to advances in US technologies. Nowadays, a pancreatic US study could be considered complete if multiparametric, including the use of Doppler imaging, US elastography, and contrast-enhanced imaging for the study of a pancreatic mass. A complete US examination could contribute to a faster diagnosis, especially if the pancreatic lesion is incidentally detected, addressing second-step imaging modalities correctly.

Pancreatic neuroendocrine tumours: Grade is superior to T, N, or M status in predicting outcome and selecting patients for chemotherapy:A retrospective cohort study in the SEER database

BACKGROUND

Pancreatic neuroendocrine tumours (pNETs) are a rare and heterogeneous group of tumours with an increasing incidence. Current staging criteria for pNETs remain limited and controversial. Meanwhile, the impact of chemotherapy on overall survival has not been fully defined.

OBJECTIVES

The current study aimed to explore epidemiologic trends of pancreatic neuroendocrine tumours (pNETs). To determine feasible improvements to staging criteria and investigate the relationship between chemotherapy and survival.

METHODS

A retrospective cohort study design was used to analyse annual cancer incidence rates, patient demographics, tumour site and stage, and treatment of pNETs. Data were obtained from the National Cancer Institute's SEER registry for all patients diagnosed with pNETs between January 1973 and December 2015.

RESULTS

Patients diagnosed after 2010 were more likely to present with age greater than 45 years, T0, T1 status, N0 status, M0 status, and well differentiation. Current AJCC staging criteria was applicable to patients with well differentiation, but not other differentiation. The revised system, defined by Grade, T, N, and M status, could robustly discriminate between survival curves. Chemotherapy was associated with significantly improved survival for patients with poorly differentiated and undifferentiated tumour grading.

CONCLUSIONS

Grade is superior to 'T', 'N', or 'M' status in predicting outcomes and selecting patients for chemotherapy. It is necessary and feasible to combine grade into current staging criteria.

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.

Homogenously isoattenuating insulinoma on biphasic contrast-enhanced computed tomography: Little benefits of diffusion-weighted imaging for lesion detection

The aim of the present study was to evaluate the diagnostic benefit of diffusion-weighted imaging (DWI) in the detection of homogenous isoattenuating insulinoma on biphasic contrast-enhanced computed tomography (CT) preoperatively and to determine which magnetic resonance (MR) sequences exhibited the best diagnostic performance. A total of 44 consecutive patients who underwent biphasic contrast-enhanced CT and conventional MR imaging (MRI), including DWI on a 3T scanner, were identified retrospectively. Apparent diffusion coefficient (ADC) values of insulinomas and the surrounding pancreatic parenchyma were compared using a Wilcoxon signed-rank test. Receiver operating characteristic analysis was used to compare the diagnostic accuracy of four randomized image sets [T2-weighted image (WI), axial T1WI, DWI and T2WI + DWI] for each reader. Axial T1-weighted MRI exhibited the highest relative sensitivity for each reader; DWI alone exhibited the lowest relative sensitivity and the lower inter-reader agreement. There was no significant difference in lesion detection between T2WI and T2WI + DWI image sets for each reader. The ADC values of the insulinoma were significantly lower compared with those of the surrounding parenchyma. In conclusion, DWI does not benefit the detection of homogenous isoattenuating insulinoma. Axial T1WI is the optimal pulse sequence. Quantitative assessment of the tumor ADC values may be a useful tool to characterize identified pancreatic neoplasms.

A meta-analysis of Prognostic factor of Pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (pNENs) are a group of clinically rare and heterogeneous diseases of the pancreas. However, the prognostic factors for this disease in patients still remain controversial. The purpose of our study is to evaluate the predictive roles of those prognostic factors for pNENs. All related articles published until Sep 17, 2017 were identified via PubMed, EMBASE, Web of Science, Ovid and the Cochrane Library. Studies that examined the prognostic factors of pNENs were enrolled. 17 articles (2822 patients) were finally included in this study. The pooled data suggested that patients with positive surgical resection margin and lymph node, advanced G stage and TMN stage, organ metastasis, vascular invasion and the necrosis of specimens had a decreased overall survival for pNENs. Similarly, patients with functional tumors might have a poor prognosis. However, age, gender, surgical type and size of tumor could not be regarded as prognostic factors for pNENs. Our analytic data demonstrated that surgical resection margin, G stage, TMN stage, lymph node, metastasis, vascular invasion and the necrosis could be prognostic factors for pNENs. Our study may assist doctors to screen patients with different prognosis more efficiently during follow-up and select appropriate treatment measures.

Diffuse Pancreatic Neuroendocrine Tumor: A Rare Presentation

Diffuse involvement of the pancreas in neuroendocrine tumor is a rare presentation, and its appearance on In-111 pentetreotide scan has not been reported earlier in the literature. We present the whole body images from In-111 pentetreotide scan, contrast-enhanced computed tomography images, and histopathology correlation.

Clinical outcomes and prognostic factors of resected pancreatic neuroendocrine neoplasms: A single-center experience in China

The aim of the present study was to investigate the clinical, pathological and prognostic characteristics of Chinese patients with resected pancreatic neuroendocrine neoplasms (p-NENs). Data from patients who were surgically treated and pathologically diagnosed with p-NENs at the Department of Pancreatic Oncology of the Fudan University Shanghai Cancer Center (Shanghai, China), between January 2003 and July 2015, were evaluated using univariate and multivariate analyses. A total of 162 patients with p-NENs met the criteria of the present study and were included in the analysis. Patients with poorly differentiated pancreatic neuroendocrine carcinoma (p-NEC) exhibited a significantly increased rate of lymph node metastasis, as compared with patients with grade (G)1/G2 pancreatic neuroendocrine tumors (p-NETs) (62.5 vs. 20.5%, P=0.003). Univariate analysis identified that the following factors led to decreased overall survival (OS): Lymph node metastasis (P=0.001, vs. the absence of lymph node metastasis); distant metastasis (P=0.043, vs. the absence of distant metastasis); resection margin R1/R2 (P=0.030, vs. R0 resection); NEC G3 (P<0.001, vs. NET G1). Following the multivariate analysis, NEC G3 remained a statistically significant risk factor (HR=12.593; 95% CI, 3.476-45.622; P<0.001, vs. NET G1/G2). Furthermore, according to the proliferation marker protein Ki-67 staining index, assigning a grade using the proliferative index (G1, ≤5%; G2, >5-20%; G3, >20%) was more efficient for prognostic stratification compared with the European Neuroendocrine Tumor Society (Berlin, Germany)/World Health Organization (Geneva, Switzerland) 2010 grading classification. The present study indicated that p-NEC was an important predictor of decreased OS in Chinese patients. Furthermore, a Ki-67 staining index of 5% represented a more efficient value for the distinction between G1 and G2.

Insulinoma Detection With MDCT: Is There a Role for Whole-Pancreas Perfusion?

OBJECTIVE

The purpose of this study is to investigate the role of whole-pancreas perfusion in detecting insulinomas with the use of MDCT.

MATERIALS AND METHODS

From January 2011 to December 2011, a total of 70 consecutive patients (33 men and 37 women; mean age, 46 years; range, 17-73 years) who underwent biphasic contrast-enhanced CT and whole-pancreas CT perfusion for suspected insulinomas were identified retrospectively. Patients were monitored for at least 3 years. Two radiologists who were blinded to the clinical and surgical data independently evaluated the images, first assessing only the biphasic contrast-enhanced CT images to detect tumor and assess diagnostic confidence on a 5-point scale. Next, perfusion parametric maps were evaluated and pancreatic perfusion parameters measured, and the presence of tumor was reidentified using a combination of the biphasic CT and perfusion image sets. A ROC curve was generated to compare the diagnostic accuracy of the two image sets.

RESULTS

The mean blood flow (BF) values of both the insulinomas and the insulinoma-harboring regions were statistically significantly higher (p < 0.01, for both) than the BF value of tumor-free pancreatic parenchyma. For the detection of insulinoma, biphasic CT had a sensitivity of 88.1%, a specificity of 85.7%, a positive predictive value of 91.1%, and a negative predictive value of 81.4%, whereas combined biphasic CT and perfusion had a sensitivity of 94.6%, a specificity of 94.7%, a positive predictive value of 96.7%, and a negative predictive value of 91.5%. The mean area under the ROC curve increased from 0.939 with biphasic CT to 0.999 with the addition of perfusion. Nine of 46 tumors (19.6%) for which findings were negative (n = 2) or indeterminate (n = 7) on biphasic CT were correctly diagnosed with the addition of perfusion.

CONCLUSION

The addition of pancreatic perfusion to biphasic contrast-enhanced CT may improve the detection of insulinomas.

Systematic Review and Meta-Analysis on the Role of Chemotherapy in Advanced and Metastatic Neuroendocrine Tumor (NET)

BACKGROUND/OBJECTIVES

In the era of somatostatin analogues and targeted therapies, the role of chemotherapy in NET remains largely undefined. This systematic review aimed to assess the effect of chemotherapy on response rates (RR), progression-free survival (PFS), overall survival (OS) and toxicity compared to other chemotherapies/systemic therapies or best supportive care in patients with advanced or metastatic NET.

METHODS

Randomised controlled trials (RCTs) from 1946 to 2015 were identified from MEDLINE, EMBASE, other databases and conference proceedings. Review of abstracts, quality assessment and data abstraction were performed independently by two investigators. Meta-analyses were conducted using Mantel-Haenszel analysis with random-effects modelling.

RESULTS

Six RCTs comparing standard streptozotocin plus 5-fluorouacil (STZ/5FU) chemotherapy to other chemotherapy regimens, and 2 comparing this to interferon (IFN) were included. Only 1 study was considered at low risk of bias. STZ/5-FU was no different to other chemotherapies in response rate [RR 0.96; 95% confidence interval (CI) 0.72-1.27], PFS (RR 0.95; CI 0.81-1.13), or OS (RR 1.03; CI 0.77-1.39). IFN may produce higher response than STZ/5FU (RR 0.20; CI 0.04-1.13), but event rates were small and survival was no different. Interferon was associated with higher overall haematological (RR 0.47; CI 0.27-0.82) and lower overall renal toxicity (RR 3.61; CI 1.24-10.51).

CONCLUSION

Strong evidence is lacking in the area of chemotherapy in neuroendocrine tumors. There is currently no evidence that one chemotherapeutic regimen is significantly better than the other, nor is interferon better than chemotherapy. There is an urgent need to design RCTs comparing modern chemotherapy to other agents in NET.

Islet Cell Tumors of the Pancreas

Islet cell tumors of the pancreas, also known as pancreatic neuroendocrine tumors, constitute less than 5% of pancreatic tumors, and 7% of all neuroendocrine tumors. Most are non-functional, and patients often present with metastatic disease. Functional tumors present with distinct clinical syndromes. Accurate staging is critical as surgery is both the cornerstone of treatment, and the only hope for cure. Medical management involves treating the manifestations of hormonal excess, and using somatastatin analogues when appropriate. Systemic chemotherapy, targeted molecular therapy, and peptide receptor radiotherapy may be used for refractory disease in lieu of or as an adjunct to surgery.

Risk factors for aggressive nonfunctional pancreatic neuroendocrine tumors and the role of endoscopic ultrasound guided fine-needle aspiration

Background:

Nonfunctional pancreatic neuroendocrine tumors (NF-pNETs) are increasingly being diagnosed but management, especially of small tumors, remains a clinical dilemma. Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) is now routinely used for diagnosis of pancreatic neuroendocrine tumors (pNETs) but has not been well studied as a tool for identifying aggressive disease.

Materials and Methods:

A systematic search of the cytology database identified all patients at our center who underwent EUS-FNA from 1999 through 2011 and were diagnosed with NF-pNET.

Results:

A total of 50 patients were identified. Though patients with metastatic disease had a mean tumor size of 40 mm compared to 25 mm in patients without metastatic disease (P = 0.04), we also identified several patients with tumors <20 mm who presented with metastatic disease. Furthermore, we found no statistically significant difference in metastatic disease between tumors <20 mm and >20 mm (P = 0.13). Using receiver operating characteristic (ROC) analysis, we found that using a cutoff point of 20 mm only led to a sensitivity of 85% in screening for metastases, while lowering the cutoff point to 18 mm allowed for a sensitivity of 95%.

Conclusion:

Currently, guidelines suggest that only patients with tumors greater than 20 mm undergo surgical resection, as tumors less than this size are thought to have low risk of metastases. Our analysis suggests that these recommendations could lead to undertreating patients with small tumors. Tumor size alone may be inadequate as a marker for aggressive NF-pNETs. Given this, other risk factors for aggressive pNETs should be studied to help identify the patients most likely to benefit from surgery.

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.

Does long-term survival exist in pancreatic adenocarcinoma?

BACKGROUND

We conducted a population-based study to investigate long-term survival in patients diagnosed with a (suspected) pancreatic adenocarcinoma.

METHODS

All patients diagnosed with a pancreatic adenocarcinoma or with a pathologically unverified tumour of the pancreas between 1993 and 2008 in the South of the Netherlands were selected from the Netherlands Cancer Registry (NCR). Medical charts of patients who were alive five years or longer since diagnosis were reviewed.

RESULTS

A total of 2 564 patients were included, of whom 1 365 had a pancreatic adenocarcinoma and 1 199 had a pathologically unverified pancreatic tumour. Five-year survival of patients with pathologically verified adenocarcinomas was 1.7% (24 of 1 365 patients). Twenty-one-one of these 24 long-term survivors were among the 207 cases that underwent surgical resection as initial treatment; five-year survival after resection thus being 10.1%. Half of the long-term survivors who underwent surgical resection still eventually died of recurrent disease. Five-year survival among patients with clinically suspected but microscopically unverified pancreatic tumours was 1.3% (16 of 1 199 patients). In 15 of these 16 long-term survivors the initial clinical diagnosis was revised: 14 had benign disease and one a premalignant tumour.

CONCLUSIONS

Long-term survival among patients with pancreatic adenocarcinoma is extremely rare. As long-term survival in clinically suspected but pathologically unverified cancer is very unlikely, repeated fine needle aspiration or, preferably, histological biopsy is recommended in order to establish an alternative diagnosis in patients who survive longer than expected (more than 6-12 months).

Pancreatic Neuroendocrine Tumor with Atypical Radiologic Presentation

An atypical radiographic presentation of a rare non-functional pancreatic neuroendocrine tumor as seen on US, CT and MRI is described. Radiographic-pathologic correlation via gross autopsy specimens and immuno-histochemical staining demonstrates the pancreas to be markedly enlarged with extensive calcifications and numerous tiny cysts secondary to diffuse neoplastic infiltration without a focal mass.

Cutaneous metastasis as an initial presentation of a non-functioning pancreatic neuroendocrine tumor

Non-functioning pancreatic neuroendocrine tumors (NF-PNETs) are rare tumors that account for 2% of all pancreatic malignancy. About 60% of NF-PNETs present distant metastases and usually hepatic metastases. However, cutaneous metastases are very rare. Herein, we report our experience with a 60-year-old male who visited our outpatient clinic with a mass on his left hip. An abdominal computerized tomography scan demonstrated not only a left hip mass and an enlarged left inguinal lymph node, but also a huge heterogeneous enhancing mass on the pancreas. Initially, we removed the metastatic lesions, which was a small cell neuroendocrine carcinoma with 50% of the Ki-67 index in the histopathological report. After 3 wk, we performed a total pancreatectomy and a total gastrectomy. Four weeks after the 1^st operation, we detected a recurrence at the operative bed on his left hip, and subsequently removed the recurring mass. The patient was receiving chemotherapy based on etoposide and cisplatin treatment.

Behavior of Small, Asymptomatic, Nonfunctioning Pancreatic Neuroendocrine Tumors (NF-PNETs)

Small nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) usually exhibit minimal or no growth over many years. However, there is a controversy regarding the optimal management of incidentally discovered, small NF-PNETs. This study aimed to gain insights into tumor behavior and potential strategies for clinical management.We retrospectively reviewed a total of 202 patients with a suspected PNET (size 2 cm or smaller) at Samsung Medical Center from January 1, 1995 to April 30, 2012. Among these patients, 72 patients were excluded and 145 patients were enrolled in our study. Patients were included if the size of the tumor was ≤2 cm without familial syndrome, radiographic evidence of local invasion or metastases.Among the 145 patients, 76 patients (52.4%) had pathologically confirmed PNETs. Eleven (14.5%) and 3 (3.9%) of these 76 patients were diagnosed with NET G2 and G3, respectively. PNETs measuring 1.5 cm or more in size had a higher probability of being classified as NET G2 or G3 compared with PNETs measuring <1.5 cm (P = 0.03). Older age (≥55 years) and a meaningful tumor growth (≥20% or ≥5 mm) were significantly associated with NET G2 or G3 (P < 0.05).Older age (≥55 years), larger tumor size (≥1.5 cm), and a meaningful tumor growth (≥20% or ≥5 mm) were associated with NET G2 or G3. Intensive follow-up could be an acceptable approach in small (especially <1.5 cm), asymptomatic, NF-PNETs.

Radiofrequency ablation of pancreatic neuroendocrine tumors: a pilot study of feasibility, efficacy, and safety

OBJECTIVE

This study aimed to assess the feasibility, safety, and efficacy of radiofrequency ablation (RFA) of pancreatic neuroendocrine tumors (PNETs).

METHODS

We performed RFA on 10 patients (7 women) aged 38 to 75 years with histologically diagnosed PNETs (secreting in 3 cases) who could not or would not undergo surgical resection. Tumor nodules (diameter, 0.9-2.9 cm; mean [SD], 1.6 [0.5] cm) were located in the head (n = 7) or body (n = 3) of the pancreas. Ultrasound-guided RFA was performed percutaneously (n = 7), endoscopically (n = 1), or intraoperatively (n = 2) using commercially available equipment. Complete ablation was defined as absence of enhancing tissue at the tumor site on contrast-enhanced imaging studies and normalization of previously elevated serum hormone levels.

RESULTS

Complete ablation was achieved with 1 (n = 9) or 2 (n = 1) RFA procedures. All neuroendocrine syndromes regressed within 24 hours of treatment. No recurrences were observed during follow-up (range, 12-60 months; median [SD], 34 [14] months). No deaths occurred. Major complications included acute pancreatitis in 3 patients, 2 of whom developed pancreatic fluid collections that were successfully managed with ultrasound-guided drainage and endoscopy.

CONCLUSIONS

Radiofrequency ablation is a feasible, safe, and effective option for patients with small PNETs who cannot or do not want to undergo surgical resection.

Quality of life, resource utilisation and health economics assessment in advanced neuroendocrine tumours: a systematic review

Neuroendocrine tumours (NET) are often diagnosed at an advanced stage when the prognosis is poor for patients, who often experience diminished quality of life (QoL). As new treatments for NET become available, it is important to characterise the associated outcomes, costs and QoL. A comprehensive search was performed to systematically review available data in advanced NET regarding cost of illness/resource utilisation, economic studies/health technology assessment and QoL. Four rounds of sequential review narrowed the search results to 22 relevant studies. Most focused on surgical procedures and diagnostic tools and contained limited information on the costs and consequences of medical therapies. Multiple tools are used to assess health-related QoL in NET, but few analyses have been conducted to assess the comparative impact of available treatment alternatives on QoL. Limitations include English language and the focus on advanced NET; ongoing terminology and classification changes prevented pooled statistical analyses. This systematic review suggests a lack of comparative economic and outcomes data associated with NET treatments. Further research on disease costs, resource utilisation and QoL for patients with advanced NET is warranted.

Rare neuroendocrine tumours: results of the surveillance of rare cancers in Europe project

Because of the low incidence, and limited opportunities for large patient volume experiences, there are very few relevant studies of neuroendocrine tumours (NETs). A large population-based database (including cancer patients diagnosed from 1978 to 2002 and registered in 76 population-based cancer registries [CRs]), provided by the project 'surveillance of rare cancers in Europe' (RARECARE) is used to describe the basic indicators of incidence, prevalence and survival of NETs, giving a unique overview on the burden of NETs in Europe. NETs at all cancer sites, excluding lung, were analysed in this study. In total over 20,000 incident cases of NETs were analysed and a data quality check upon specific NETs was performed. The overall incidence rate for NETs was 25/1,000,000 and was highest in patients aged 65 years and older with well differentiated endocrine carcinomas (non-functioning pancreatic and gastrointestinal) (40 per 1,000,000). We estimated that slightly more than 100,000 people were diagnosed with NETs and still alive in EU27 at the beginning of 2008. Overall, NETs had a 5 year relative survival of 50%; survival was low (12%) for poorly differentiated endocrine carcinoma, and relatively high (64%) for well differentiated carcinoma (not functioning of the pancreas and digestive organs). Within NETs, endocrine carcinoma of thyroid gland had the best 5-year relative survival (82%). Because of the complexity and number of the different disciplines involved with NETs (as they arise in many organs), a multidisciplinary approach delivered in highly qualified reference centres and an international network between those centres is recommended.

Contrast-enhanced ultrasound in the differential diagnosis of exocrine versus neuroendocrine pancreatic tumors

OBJECTIVES

Contrast-enhanced ultrasound (CEUS) has been developed to better characterize the microvasculature of solid masses in several organs, including the pancreas. In this study, we assessed CEUS accuracy in differentiating exocrine from endocrine pancreatic tumors.

METHODS

A total of 127 patients with single, undetermined pancreatic masses were prospectively examined with transabdominal ultrasound and CEUS, before surgical resection or percutaneous biopsy.

RESULTS

Exocrine and endocrine pancreatic tumors showed different intralesional vascularization patterns: 98.9% (90/91) of exocrine tumors were hypoenhancing, whereas 95.8 % (23/24) of endocrine tumors had a hypervascular supply. A hypoenhancing pattern, indicative of ductal adenocarcinoma, had a significant (P < 0.001) diagnostic accuracy of 91.3% with a sensitivity of 96.8%, a specificity of 85.3%, a positive predictive value and a negative predictive value of 94.7% and 90.6%, respectively. The hyperenhancing pattern, indicative of endocrine tumors, had a significant (P = 0.031) diagnostic accuracy of 73.8% with a sensitivity of 83.3%, a specificity of 60.0%, a positive predictive value and negative predictive value of 83.3% and 60.0%, respectively.

CONCLUSIONS

Contrast-enhanced ultrasound has a valuable diagnostic accuracy in differentiating exocrine from endocrine pancreatic tumors, which is a fundamental step to address appropriate histological evaluation, therapeutic approach, and follow-up.

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.

Surgical strategies for non-functioning pancreatic neuroendocrine tumours

BACKGROUND

The purpose of this study was to identify management strategies for non-functioning pancreatic neuroendocrine tumours (NF-PNETs) by analysis of surgical outcomes at a single institution.

METHODS

Archived records of patients with NF-PNETs who underwent surgery between 1994 and 2010 were reviewed.

RESULTS

Among 125 patients, the median tumour size was 2·5 (range 0·15-20·5) cm. Of the 51 NF-PNETs with a diameter of no more than 2 cm, 12 (24 per cent) were diagnosed as carcinoma. Overall 20 patients (16·0 per cent) had metastases to the lymph nodes. The minimum size of the tumour with lymph node metastasis was 1·2 cm. Having a NF-PNET of 2 cm or larger significantly increased the probability of a poorly differentiated carcinoma (P = 0·006), and having a NF-PNET of at least 2·5 cm significantly increased the probability of lymph node metastasis (P = 0·048). The 5-year cumulative survival rate after curative resection was 89·7 per cent. During a median follow-up of 31·5 months, there were 27 recurrences (23·1 per cent) and 13 disease-specific deaths (11·1 per cent) among the 117 patients who had an R0 resection. All patients who underwent repeat operations were alive without additional recurrence after a mean(s.d.) follow-up of 27·1(18·0) months.

CONCLUSION

Curative surgery should be performed for control of primary NF-PNETs. Lymph node dissection for NF-PNETs of 2·5 cm or larger and at least node sampling for tumours with a diameter of 1 cm or more are recommended. Debulking surgery should be considered for advanced tumours.

Bone lesions in recurrent glucagonoma: A case report and review of literature

Glucagonomas are rare neuroendocrine tumors that arise from α cells of the pancreatic islets. Most of them are malignant and usually present as metastatic disease. Sites most commonly involved in metastases are the liver and regional lymph nodes. Bone metastases are rare events and only a few cases have been reported in the literature. We present the case of a 53-year-old male with a medical history of recurrent non-functioning glucagonoma. He presented 17 years after the initial diagnosis with new blastic bone lesions involving the T1 vertebra and the sacrum. Diagnostic steps and medical management in metastatic glucagonoma are also reviewed.

Comparison of functional and nonfunctional neuroendocrine tumors in the pancreas and peripancreatic region

OBJECTIVE

To present our experience of 93 neuroendocrine tumors (NETs) in the pancreas and peripancreatic region, with emphasis on how resectability affects long-term survival and the impact of functional status on the survival outcome.

METHODS

Ninety-three patients with NETs in the pancreas and peripancreatic region were included to compare the clinical features between functional and nonfunctional NETs. Prognostic factors were determined by univariate and multivariate analyses.

RESULTS

There were 39 functional (41.9%) and 54 nonfunctional NETs (58.1%). According to World Health Organization (WHO) tumor categories, there were 57 well-differentiated tumors (61.3%), 26 well-differentiated carcinomas (28%), and 10 poorly differentiated carcinomas (10.8%). Univariate analysis showed that functional status of the tumor, tumor stage, lymph node status, and pathological classification were prognostic factors for both disease-free survival and disease-specific survival. Resectability did not influence the survival outcome, with the resectable and unresectable groups demonstrating a 5-year disease-specific survival of 86.4% and 65.6%, respectively (P = 0.210). Only the WHO pathological classification was an independent prognostic factor after multivariate analysis.

CONCLUSIONS

Irresectability does not necessarily preclude long-term survival for both functional and nonfunctional NETs. It is the WHO pathological classification, instead of hormonal functional status, that is an independent prognostic factor and has impact on the survival outcome.

Neuroendocrine tumors and tumor syndromes in childhood

Endocrine and neuroendocrine cells form a large and diverse array of cell types. They are present in the form of specialized organs, such as the pituitary, parathyroid, thyroid, and adrenal gland, or in the form of the diffuse neuroendocrine system in the respiratory and digestive tracts. Neuroendocrine tumors are a heterogeneous group of neoplasms, yet they present certain unifying features. These include frequent hormonal overproduction that leads to specific symptoms and a typical immunohistochemical staining profile with chromogranin A and synaptophysin reactivity. Over the past decades, many neuroendocrine tumors have been described in the context of heritable tumor syndromes, and there exist several syndromes that are almost entirely composed of neuroendocrine tumors. Tumors occurring as part of these hereditary syndromes are characterized by specific genetic abnormalities that have helped our understanding of tumorigenesis, and they frequently appear at a young age. It is therefore important for the pediatric pathologist to be aware of specific histologic characteristics of neuroendocrine tumors in childhood and of their association with specific tumor syndromes. This may alert other clinicians to the possibility of multiple tumors in the patient or his family members. This review focuses on hereditary syndromes with neuroendocrine tumors, including multiple endocrine neoplasia types 1 and 2, Von Hippel-Lindau disease, neurofibromatosis type 1, Carney complex, pheochromocytoma-paraganglioma syndrome, and familial nonmedullary thyroid carcinoma. In addition, several individual neuroendocrine tumors are described, such as medullary thyroid carcinoma, gastroenteropancreatic tumors, pheochromocytoma, and paraganglioma, emphasizing specific histopathologic characteristics.

[Contribution of endoscopic ultrasonography to the diagnosis of neuroendocrine pancreatic tumors]

Neuroendocrine pancreatic tumors (NEPT) are relatively infrequent tumors, with an incidence of approximately 1 case per 100.000 inhabitants, representing only 1-2% of pancreatic neoplasms. Localization and staging of NEPT prior to surgery is essential to allow treatment optimization. However, localizing these tumors is often difficult, mainly because of their small size. On ultrasound, NEPT usually appear as rounded, hypoechoic and homogeneous lesions, with precise limits and peripheral enhancement due to their significant vascularization. The most precise technique for the diagnosis and localization of NEPT is endoscopic ultrasound (EUS), with a sensitivity and specificity as high as 95%, clearly superior to those of other imaging procedures. Overall diagnostic accuracy may even be increased by associating EUS-guided fine-needle aspiration.

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.

Contrast-enhanced ultrasound of the pancreas

The introduction of contrast-enhanced ultrasonography (CEUS) has led to major improvements in the diagnostic capabilities of ultrasound (US). The innovative use of CEUS for study of the pancreas has created the need for a definition of the most frequent dynamic features of solid and cystic masses. CEUS is less expensive compared to computed tomography and magnetic resonance imaging and is able to significantly improve the accuracy of US, allowing better characterization and staging of pancreatic pathologies.

Imaging of neuroendocrine gastroenteropancreatic tumours

The role of imaging in functioning endocrine tumours (FETs) is primarily to detect the tumour, that is, to verify lesion number and location. Radiological detection of carcinoid tumours is limited by typical tumour location throughout the gastrointestinal tract or appendix and is therefore dependent on the tumour being large enough to make it recognisable in that site. The most common FET is insulinoma, which is commonly characterised by the typical appearance of a hypervascular lesion at multidetector-row computed tomography and magnetic resonance imaging. A particularly important role is played by intraoperative ultrasound in defining the exact number of lesions, their relationship with adjacent vascular structures and the pancreatic duct for the purposes of correct surgical planning (enucleation or resection). In the setting of nonfunctioning endocrine tumours (NFETs), which manifest late as large masses causing compression symptoms or as incidental findings, imaging is not primarily aimed at tumour detection, as this is relatively easy given the large size of the lesions. Rather, its role is to characterise the tumour and, in particular, to differentiate pancreatic NFET from ductal adenocarcinoma, as in comparison, malignant NFETs have a more favourable prognosis (5-year survival rate 40% compared with 3%-5% for adenocarcinoma) and therefore require different treatment approaches. As NFET are often malignant, they also require accurate staging and appropriate follow-up. In 80% of cases, NFETs have a "typical" imaging appearance: location in the pancreatic head, large dimensions (diameter between 5 and 15 cm, >10 cm in 30% of cases), capsule, sharp and regular margins owing to the expansile and noninfiltrative growth pattern, solid density and arterial hypervascularity. Some 20% of NFETs display different imaging characteristics ("atypical" appearance) as a result of arterial hypovascularity due to the presence of abundant fibrous stroma. Lastly, a small percentage of NFETs has yet a different appearance ("unusual") due to the cystic nature and/or diffuse location throughout the pancreatic parenchyma.

Pancreatic neuroendocrine tumors: the impact of surgical resection on survival

BACKGROUND

Although surgical resection is generally recommended for patients with localized pancreatic neuroendocrine tumors (PNETs), the impact of resection on overall survival is unknown. The authors investigated the survival advantage of pancreatic resection using a national database.

METHODS

This is a retrospective survival analysis of patients with PNETs from the Surveillance, Epidemiology, and End Results database (1988-2002).

RESULTS

A total of 728 patients with PNETs were identified with a median survival of 43 months using Kaplan-Meier survival methods. Resection of tumor was associated with significantly improved survival compared with those patients who were recommended for but did not undergo resection (114 months vs 35 months; P < .0001). This survival benefit was demonstrated for patients with localized, regional, and metastatic disease. A multivariable Cox proportional hazards model was constructed to assess the overall effect of surgical resection on survival, and demonstrated an adjusted odds ratio of 0.48 (95% confidence interval, 0.35-0.66) compared with those who were recommended for surgery but did not proceed to surgery.

CONCLUSIONS

The authors have demonstrated in a large national study that resection of primary tumor in patients with PNETs is associated with improved survival across all disease stages. Patients with localized, regional, and metastatic PNETs who are reasonable operative candidates should be considered for resection of their primary tumors.

Endocrine neoplasms of the pancreas: pathologic and genetic features

CONTEXT

Pancreatic endocrine neoplasms (PENs) are diagnostically challenging tumors whose natural history is largely unknown. Histopathology allows the distinction of 2 categories: poorly differentiated high-grade carcinomas and well-differentiated neoplasms. The latter include more than 90% of PENs whose clinical behavior varies from indolent to malignant and cannot be predicted by their morphology.

OBJECTIVES

To review the literature and report on additional primary material about the clinicopathologic features, classification, staging, grading, and genetic features of PENs.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institution.

CONCLUSIONS

The diagnosis of PEN is generally easy, but unusual features may induce misdiagnosis. Immunohistochemistry solves the issue, provided that the possibility of a PEN has been considered. Morphology allows the distinction of poorly differentiated aggressive carcinomas from well-differentiated neoplasms. The World Health Organization classification criteria allow for the discernment of the latter into neoplasms and carcinomas with either benign or uncertain behavior. The recently proposed staging and grading systems hold great promise for permitting a stratification of carcinomas into clinically significant risk categories. To date, inactivation of the MEN1 gene remains the only ascertained genetic event involved in PEN genesis. It is inactivated in roughly one-third of PENs. The degree of genomic instability correlates with the aggressiveness of the neoplasm. Gene silencing by promoter methylation has been advocated, but a formal demonstration of the involvement of specific genes is still lacking. Expression profiling studies are furnishing valuable lists of mRNAs and noncoding RNAs that may advance further the research to discover novel markers and/or therapeutic targets.

Cystic pancreatic neuroendocrine neoplasms with uncertain malignant potential: report of two cases

Neuroendocrine tumors of the pancreas (NETP) represent only 1%-2% of all pancreatic neoplasms. They can be classified as functioning or non-functioning, respectively, according to the presence or absence of paraneoplastic syndrome. Case 1 concerned a 70-year-old woman with a cystic lesion of the pancreatic head and body. All tumor markers were negative. The patient underwent a distal pancreatectomy. The histology revealed a well-differentiated endocrine tumor with uncertain malignant potential. Case 2 was a 61-year-old man with chronic polyserositis. The serum tumor markers were negative, while he was strongly positive for intracystic tumor markers carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA 125. The patient underwent a cephalo-pancreatic duodenectomy. The preoperative differential diagnosis of cystic NETP is still a challenge due to the high rate of the nonfunctional variant. Although cystic NETPs are well differentiated, they are still tumors with a malignant potential, and therefore an early diagnosis and radical surgical resection could be associated with a better long-term survival.

Clinical outcome and long-term survival in 118 consecutive patients with neuroendocrine tumours of the pancreas

BACKGROUND

The aim was to assess the clinical relevance of the World Health Organization and tumour node metastasis (TNM) classifications in patients with pancreatic neuroendocrine tumours (pNETs).

METHODS

Prospectively collected data from 118 consecutive patients with a pNET receiving surgical intervention were analysed.

RESULTS

Forty-one patients had well differentiated neuroendocrine tumours, 64 had well differentiated neuroendocrine carcinomas and 13 had poorly differentiated neuroendocrine carcinomas. Five-year survival rates were 95, 44 and 0 per cent respectively (P < 0.001). There was no difference in survival after R0 and R1/R2 resections in patients with neuroendocrine carcinomas (P = 0.905). In those with well differentiated neuroendocrine carcinomas, any resection and having a clinically non-functional tumour significantly increased survival (P = 0.003 and P = 0.037 respectively). The TNM stage was I in 37 patients, II in 15 patients, III in 32 patients and IV in 34 patients. There were significant differences in 5-year survival between stage I and II (88 and 85 per cent respectively) and stage III and IV (31 and 42 per cent respectively) (P = 0.010).

CONCLUSION

Both classifications accurately reflect the clinical outcome of patients with pNET. The resection status may not be critical for long-term survival in patients with pNET.

Is surgery indicated for patients with symptomatic nonfunctioning pancreatic neuroendocrine tumor and unresectable hepatic metastases?

BACKGROUND

Patients with advanced pancreatic neuroendocrine tumor, even in the presence of unresectable hepatic metastases, have survival usually measured in years than in months. Theoretically, we would have reason to resect symptomatic primary pancreatic neuroendocrine tumors from these patients palliatively. However, the effect and feasibility of removing symptomatic primary pancreatic neuroendocrine tumor in patients with unresectable hepatic metastases has never been addressed.

METHODS

In 2000, we instituted a prospective study to resect symptomatic primary tumors and treat unresectable hepatic metastases by lanreotide and hepatic artery embolization in patients with definite tissue proof of pancreatic neuroendocrine tumor.

RESULTS

Thirteen patients were included in this study; seven patients underwent pancreaticoduodenectomy, and six underwent distal pancreatectomy and splenectomy. There were no operative deaths. Eight of thirteen patients had no radiologic evidence of disease progression. The other five patients had disease progression by their 6-month follow-up; they underwent hepatic artery chemoembolization or chemotherapy. One patient died of multiple lung and bone metastases 80 months after operation, and one patient died of continuous progression of liver metastases 18 months after operation. Telephone interviews of 11 patients who survived revealed that 10 reported improved quality of life after resection of symptomatic primary pancreatic neuroendocrine tumor and one patient reported no change.

CONCLUSIONS

We suggest that symptomatic primary pancreatic neuroendocrine tumors should be resected even when unresectable hepatic metastases are found at diagnosis because of the relatively low risk of pancreatic surgery, effective elimination of symptoms caused by primary tumors, and slow progression of hepatic metastases under lanreotide and hepatic artery embolization.