Surgical management of pancreatic neuroendocrine tumors. Surg Today. 2011;41:1332-1343. [PMID: 21922354 DOI: 10.1007/s00595-011-4547-6]

NON-FUNCTIONING SPORADIC PANCREATIC NEUROENDOCRINE TUMOR IS AN INDEPENDENT RISK FACTOR FOR RECURRENCE AFTER SURGICAL TREATMENT

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are uncommon and heterogeneous neoplasms, often exhibiting indolent biological behavior. Their incidence is rising, largely due to the widespread use of high-resolution imaging techniques, particularly influencing the diagnosis of sporadic non-functioning tumors, which account for up to 80% of cases. While surgical resection remains the only curative option, the impact of factors such as tumor grade, size, and type on prognosis and recurrence is still unclear.

AIMS

To investigate prognostic risk factors and outcomes in patients with sporadic PNETs treated surgically.

METHODS

A retrospective analysis was conducted on patients with sporadic PNETs who underwent pancreatic resection. Data were collected from medical records.

RESULTS

A total of 113 patients were included: 32 with non-functioning tumors (NF-PNETs), 70 with insulinomas, and 11 with other functioning tumors (OF-PNETs). Patients with insulinoma were significantly younger, had a higher BMI, lower prevalence of comorbidities and ASA scores, and underwent significantly more pancreatic enucleations compared to patients with OF-PNET and NF-PNET. The insulinoma group had more grade I tumors, smaller tumor diameter, lower TNM staging, and lower disease recurrence rates. In univariate analysis, age, tumor type, tumor size, and TNM staging were identified as potential risk factors for tumor recurrence. In multivariate analysis, only the NF-PNET type was identified as an independent prognostic factor for disease recurrence.

CONCLUSIONS

NF-PNETs are an independent prognostic risk factor for disease recurrence. This finding supports the need for closer follow-up of patients with small tumors who are selected for conservative management.

Insulinoma With Ambiguous Biochemistry, Positive 68Ga-DOTA-Exendin-4 PET-CT, and Effective Endoscopic Ablation

A 75-year-old female presented with fasting hypoglycemic episodes. A supervised fast ended at 72 hours fulfilling Whipple triad, with suppressed insulin and C-peptide levels, but discordantly suppressed serum β-hydroxybutyrate levels. After 21 months of recurring symptoms, a repeat fast ended at 48 hours with Whipple triad, suppressed serum β-hydroxybutyrate level, and borderline nonsuppressed C-peptide level, suggesting endogenous hyperinsulinism. Serum insulin levels were discordantly suppressed. Computed tomography (CT) of the abdomen demonstrated an enhancing 1.36 × 0.93-cm nodule in the head of the pancreas. Endoscopic ultrasound (EUS)-guided fine-needle aspirate of the lesion derived cytology consistent with a neuroendocrine tumor, but fine-needle core biopsy returned normal pancreatic tissue. Because the results were equivocal, functional imaging with 68Gallium-DOTA-exendin-4 positron emission tomography CT was performed, which confirmed the diagnosis of a single head-of-pancreas insulinoma. The patient declined surgical resection. Oral diazoxide therapy resulted in significant peripheral edema. Hence, EUS-guided radiofrequency ablation of the lesion was performed, and the patient remains symptom free 10 months postprocedure. This case illustrates that (1) exendin-4-based positron emission tomography may help one confidently diagnose and localize insulinoma when prior biochemical or endoscopic biopsy results are ambiguous; and (2) EUS-guided radiofrequency ablation is an efficacious alternative option to surgical resection in the frail, elderly patient with insulinoma.

Diabetes Mellitus Secondary to Endocrine Diseases: An Update of Diagnostic and Treatment Particularities

Secondary diabetes mellitus is frequently ignored in specialized literature. In this narrative review, the main endocrinopathies accompanied by increased glycemic values are identified, as well as the mechanisms by which the excess or deficiency of certain hormones impact beta cell function or insulin resistance. The main endocrinopathies (acromegaly, Cushing's syndrome, Basedow-Graves' disease, pheochromocytoma, somatostatinoma and glucagonoma) and their characteristics are described along with the impact of hormone changes on blood sugar, body mass index and other parameters associated with diabetes. The overall information regarding the complex molecular mechanisms that cause the risk of secondary diabetes and metabolic syndrome is of crucial importance in order to prevent the development of the disease and its complications and particularly to reduce the cardiovascular risk of these patients. The purpose of this study is to highlight the particular features of endocrine pathologies accompanied by an increased risk of developing diabetes, in the context of personalized therapeutic decision making. The epidemiological, physiopathological, clinical and therapeutic approaches are presented along with the importance of screening for diabetes in endocrine diseases.

Sigmoid colon schwannoma difficult to distinguish from peritoneal dissemination 13 years after pancreatic neuroendocrine tumor surgery

BACKGROUND

Schwannoma, which clinicians sometimes struggle to diagnose, is a tumor arising from Schwann cells of peripheral nerves, often in the soft tissues and rarely in the gastrointestinal tract. Pancreatic neuroendocrine tumor (PNET) is rare among pancreatic tumors, and recurrence can occur long after resection. Here, we were presented with a case where a sigmoid colon schwannoma was difficult to distinguish from a postoperative recurrence of PNET and was diagnosed after laparoscopic resection.

CASE PRESENTATION

A 51-year-old man was diagnosed with PNET (NET G2) after a distal pancreatectomy (DP) 13 years ago. The patient underwent hepatectomy due to liver metastasis 12 years after initial radical surgery. The follow-up magnetic resonance imaging (MRI) after hepatectomy showed pelvic nodules, and laparoscopic surgery was performed for both diagnosis and treatment because peritoneal dissemination of PNET could not be ruled out. Since the tumor was in the sigmoid colon, a partial colon resection was performed. The histopathological diagnosis was a schwannoma, and the patient was discharged on the seventh postoperative day.

CONCLUSIONS

We experienced a case of sigmoid colon schwannoma that was difficult to differentiate from peritoneal dissemination of PNET and was later diagnosed after laparoscopic resection. In addition, this case involved a long-term postoperative recurrence of PNET that was amenable to radical resection, further establishing the importance of long-term imaging follow-up.

Multimodal Management of Grade 1 and 2 Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (p-NETs) are rare tumors with a recent growing incidence. In the 2017 WHO classification, p-NETs are classified into well-differentiated (i.e., p-NETs grade 1 to 3) and poorly differentiated neuroendocrine carcinomas (i.e., p-NECs). P-NETs G1 and G2 are often non-functioning tumors, of which the prognosis depends on the metastatic status. In the localized setting, p-NETs should be surgically managed, as no benefit for adjuvant chemotherapy has been demonstrated. Parenchymal sparing resection, including both duodenum and pancreas, are safe procedures in selected patients with reduced endocrine and exocrine long-term dysfunction. When the p-NET is benign or borderline malignant, this surgical option is associated with low rates of severe postoperative morbidity and in-hospital mortality. This narrative review offers comments, tips, and tricks from reviewing the available literature on these different options in order to clarify their indications. We also sum up the overall current data on p-NETs G1 and G2 management.

Feasibility and safety of robotic-assisted total pancreatectomy: a pilot western series

This study was designed to demonstrate non-inferiority of robot-assisted total pancreatectomy (RATP) to open total pancreatectomy (OPT) based on an intention-to-treat analysis, having occurrence of severe post-operative complications (SPC) as primary study endpoint. The two groups were matched (2:1) by propensity scores. Assuming a rate of SPC of 22.5% (non-inferiority margin: 15%; α: 0.05; β: 0.20; power: 80%), a total of 25 patients were required per group. During the study period (October 2008–December 2019), 209 patients received a total pancreatectomy. After application of exclusion and inclusion criteria, matched groups were extracted from an overall cohort of 132 patients (OPT: 107; RATP: 25). Before matching, the two groups were different with respect to prevalence of cardiac disease (24.3% versus 4.0%; p = 0.03), presence of jaundice (45.8% versus 12.0%; p = 0.002), presence of a biliary drainage (23.4% versus 0; p  = 0.004), history of weight loss (28.0% versus 8.0%; p = 0.04), and vein involvement (55.1% versus 28.0%) (p = 0.03). After matching, the two groups (OTP: 50; RATP: 25) were well balanced. Regarding primary study endpoint, SPC developed in 13 patients (26.0%) after OTP and in 6 patients (24.0%) after RATP (p = 0.85). Regarding secondary study endpoints, RATP was associated with longer median operating times [475 (408.8–582.5) versus 585 min (525–637.5) p = 0.003]. After a median follow-up time of 23.7 months (10.4–71), overall survival time [22.6 (11.2–81.2) versus NA (27.3–NA) p = 0.006] and cancer-specific survival [22.6 (11.2–NA) versus NA (27.3–NA) p = 0.02] were improved in patients undergoing RATP. In carefully selected patients, robot-assisted total pancreatectomy is non-inferior to open total pancreatectomy regarding occurrence of severe post-operative complications.

Radical resection of large metastatic non-functioning pancreatic neuroendocrine carcinoma complicated by splenic vein thrombosis and sinistral portal hypertension

INTRODUCTION AND IMPORTANCE

There are limited reports in the literature of radical surgical resection for pancreatic neuroendocrine carcinoma (PNEC). In patients with non-functioning PNEC (NF-PNEC) within the tail of the pancreas tumours can cause splenic vein thrombosis (SVT) and subsequent sinitral portal hypertension (SPH). Radical surgical resection in such patients with concomitant liver metastasis has not previously been reported.

CASE PRESENTATION

We present a 67-year old female patient who presented with a large NF-PNEC within the tail of the pancreas with liver metastasis. We performed a distal pancreatectomy, splenectomy, partial gastrectomy and liver resection to achieve radical resecton.

DISCUSSION

All patients with NF-PNEC within the tail of the pancreatic should be considered for radical surgical resection. In the presence of multi-visceral involvement and complications such as SVT and/or SPH multi-speciality surgical expertise is likely to be required.

CONCLUSION

Radical multi-visceral resection for large NF-PNEC can be safely performed in the presence of SVT and SPH.

Spleen-preserving distal pancreatectomy and lymphadenectomy for glucagonoma syndrome: A case report

RATIONALE

Glucagonoma is a rare type of functional pancreatic neuroendocrine tumor that is characterized by distinctive clinical manifestations; among these, necrolytic migratory erythema represents the hallmark clinical sign of glucagonoma syndrome and is usually presented as the initial complaint of patients.

PATIENT CONCERNS

A 30-year-old male patient was admitted to our hospital with a complaint of diffuse erythematous ulcerating skin rash for more than 10 months. He also complained of hyperglycemia and a weight loss of 15 kg in those months.

DIAGNOSIS

This patient underwent a contrast-enhanced computed tomography scan which showed a pancreatic body mass measuring approximately 6 cm with low density accompanied by partial calcification in plain scanning images and uneven enhancement in strengthening periods. In addition, laboratory tests indicated elevated fasting blood glucagon (1109 pg/mL, normal range: 50-150 pg/mL) levels. Glucagonoma syndrome was ultimately diagnosed in clinical.

INTERVENTION

Spleen-preserving distal pancreatectomy was conducted and postoperative pathology revealed the presence of glucagonoma.

OUTCOMES

The patient recovered uneventfully with the glucagonoma syndrome disappeared soon after surgery, and the postoperative plasma glucagon decreased to a normal level. Follow-up showed no recurrence for 5 years since the surgery.

LESSONS

The treatment of glucagonoma should be directed according to the stage at which the disease is diagnosed. Surgery is currently the only method available to cure the tumor, although medications are given to patients who present with advanced glucagonoma and who are not candidates for operation. Multidisciplinary therapy and multimodality treatment are advised, although these have been systematically evaluated to a lesser degree.

Mixed Malignant Pancreatic Tumour in a Rhesus Macaque (Macaca mullata)

Pancreatic islet cell tumours are rare in non-human primates. The majority of reported cases are benign islet cell adenomas in rhesus macaques (Macaca mullata). Here we describe a pancreatic tumour composed of both exocrine and endocrine cells known as a mixed acinar-neuroendocrine carcinoma in a captive rhesus macaque. A diagnosis of a mixed tumour requires intermingling of neoplastic exocrine and neuroendocrine cells and must be differentiated from ductal adenocarcinomas in which only the ductal component is neoplastic with interspersed normal neuroendocrine cells. Immunohistochemistry, including antibodies against cytokeratin 7 and chromogranin A, was used to demonstrate that both exocrine and endocrine neoplastic cells exhibited cellular atypia, invasion into the adjacent parenchyma and intraparenchymal metastasis consistent with a mixed malignant tumour. Expression of multiple hormones such as gastrin, insulin, pancreatic polypeptide and somatostatin was also observed throughout the neoplastic cell population, while the endocrine component of the neoplasm was predominantly positive for glucagon.

Combined associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) followed by left trisectionectomy and Whipple operation for PNET

Pancreatic neuroendocrine tumor (PNET) is slow-growing, and account only for 2% of all pancreatic primary tumors. Surgical resection is still the only curative treatment for PNET patients. Unfortunately, most of PNETs was found with unresectable multiple liver metastases and extrahepatic metastasis as their characteristics of non-functional and asymptomatic. With advances in liver surgery in these years, especially combined associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), provide a new curative surgical treatment for PNET with liver metastases patient. Here we report a PNET with multiple liver metastases case underwent ALPPS (followed by left trisectionectomy) and Whipple operation within one-stage.

Utility of chromogranin B compared with chromogranin A as a biomarker in Japanese patients with pancreatic neuroendocrine tumors

Objective

Currently, serum chromogranin A is a well-established biomarker for pancreatic neuroendocrine tumors; however, other pancreatic diseases, oral use of a proton pump inhibitor and renal impairment can affect chromogranin A. Meanwhile, chromogranin B, belonging to the same granin family as chromogranin A, is not fully examined in these conditions. The present study aimed to evaluate the utility of chromogranin B as a pancreatic neuroendocrine tumor biomarker.

Methods

Serum chromogranin B levels were determined by radioimmunoassay and serum chromogranin A levels by enzyme-linked immunosorbent assay in pancreatic neuroendocrine tumor (n = 91) and other pancreatic conditions, and in healthy people (n = 104), to assess the relationships with clinical features.

Results

The diagnostic ability of chromogranin B was as good as chromogranin A. The area under the curve was 0.79 for chromogranin B (sensitivity/specificity: 72%/77%), and 0.78 for chromogranin A (sensitivity/specificity: 79%/64%). Chromogranin B was not affected by proton pump inhibitor use and age, which affected chromogranin A. The number of cases without liver metastases was larger in pancreatic neuroendocrine tumor patients with positive chromogranin B and negative chromogranin A. Though chromogranin A significantly elevated cases with proton pump inhibitor treatment and had positive correlation with age, chromogranin B did not have the tendencies. However, both chromogranin B and chromogranin A elevated in the case with renal impairment. In addition, the logistic regression analysis showed that chromogranin B was superior to chromogranin A in differentiation of pancreatic neuroendocrine tumor from other pancreatic diseases.

Conclusions

Compared with chromogranin A, chromogranin B may be more useful during proton pump inhibitor treatment and can detect tumors without liver metastases. In addition, chromogranin B may be an excellent biomarker when differentiation of pancreatic neuroendocrine tumor from other pancreatic diseases is required.

Redefining the Ki-67 Index Stratification for Low-Grade Pancreatic Neuroendocrine Tumors: Improving Its Prognostic Value for Recurrence of Disease

BACKGROUND

The Ki-67 index is an established prognostic marker for recurrence after resection of pancreatic neuroendocrine tumors (PanNETs) that groups tumors into three categories: low grade (< 3%), intermediate grade (3-20%), and high grade (> 20%). Given that the majority of resected PanNETs have a Ki-67 less than 3%, this study aimed to stratify this group further to predict disease recurrence more accurately.

METHODS

The Ki-67 index was pathologically re-reviewed and scored by a pathologist blinded to all other clinicopathologic variables using tissue microarray blocks made in triplicate. All patients who underwent curative-intent resection of non-metastatic PanNETs at a single institution from 2000 to 2013 were included in the study. The primary outcome was recurrence-free survival (RFS).

RESULTS

Of 113 patients with well-differentiated PanNETs resected, 83 had tissue available for pathologic re-review. The Ki-67 index was lower than 3% for 72 tumors (87%) and between 3 and 20% for 11 tumors (13%). Considering only Ki-67 less than 3%, the tumors were further stratified by Ki-67 into three groups: group A (< 1%, n = 43), group B (1-1.99%, n = 23), and group C (2-2.99%, n = 6). Compared with group A, groups B and C more frequently had advanced T stage (T3: 44% and 67% vs 12%; p = 0.003) and lymphovascular invasion (50% and 83% vs 23%; p = 0.007). Groups B and C had similar 1- and 3-year RFS, both less than group A. After combining groups B and C, a Ki-67 of 1-2.99% was associated with decreased RFS compared with group A (< 1%). This persisted in the multivariable analysis (hazard ratio [HR] 8.6; 95% confidence interval [CI] 1.0-70.7; p = 0.045), with control used for tumor size, margin-positivity, lymph node involvement, and advanced T stage.

CONCLUSIONS

PanNETs with a Ki-67 of 1-2.99% exhibit distinct biologic behavior and earlier disease recurrence than those with a Ki-67 lower than 1%. This new stratification scheme, if externally validated, should be incorporated into future grading systems to guide both surveillance protocols and treatment strategies.

Surgical management for non-functional pancreatic neuroendocrine neoplasms with synchronous liver metastasis: A consensus from the Chinese Study Group for Neuroendocrine Tumors (CSNET)

Pancreatic neuroendocrine neoplasms (p-NENs) are slowly growing tumors with frequent liver metastasis. There is a variety of approaches to treat non-functional p-NENs with synchronous liver metastasis (LM) which complicates the determination of optimal treatment. Based on updated literature review, we discussed the treatment strategy determinants for p-NEN with LM. According to the resectability of primary tumor, the WHO 2010 grade classification and the radiological type of liver metastasis, the CSNET group reached agreements on a number of issues, including the following. Prior to treatment, biopsy is required to confirm pathology. Liver biopsy is important for more accurate grading of tumor and percutaneous core needle biopsy is more available than EUS-FNA. In patients with unresectable primary, surgical resection for liver-metastatic lesions should be avoided. Curative surgery is recommended for G1/G2 p-NET with type I LM and R1 resection also seems to improve overall survival rate. Cytoreductive surgery is recommended for G1/G2 p-NET with type II LM in select patients, and should meet stated requirements. Surgical resection for G1/G2 p-NET with type III LM and p-NEC with LM should be avoided, and insufficient evidence exists to guide the surgical treatment of G3 p-NET with LM. Liver transplantation may be an option in highly select patients. In addition, the optimal time for surgical approach is still required for more evidence.

Pancreatic neuroendocrine tumors: Nosography, management and treatment

Pancreatic neuroendocrine tumors (pNETs) represent about 7% of all NETs, 8.7% of gastroenteropancreatic NETs (GEP-NETs) and 1-2% of all pancreatic neoplasms. In the last two decades, the increased diagnosis of pNETs has generated great interest and the development of different classifications, grading and staging systems. Recently, several trials were performed in order to improve the knowledge of biomarkers and imaging and to provide an early diagnosis, but their role is still under debate. Nowadays, surgery represents the only curative approach for pNETs. Approximately 90% of pNETs are silent and non-functional; therefore, most patients are diagnosed in late stage and present metastatic (60%) or locally unresectable advanced disease (21%) with a poor prognosis. Not many therapeutic options are available for pNETs, with different treatments for G1-G2 and G3 tumors, because these diseases are still rare and trials are made up of few series of patients. At present, medical treatments is controversial. On these bases, we believe that a multidisciplinary team composed of surgeons, oncologists, endocrinologists, radiation oncologists, radiologists, pathologists and medicals nuclear is required. This paper presents a review of present state-of-the-art in the field of pNETs.

Ectopic spleen and liver hemangioma mimicking metastatic pancreatic neuroendocrine tumor

Pancreatic tumors comprise benign lesion and malignant lesion, most importantly pancreatic adenocarcinoma, acinar cell carcinoma, neuroendocrine carcinoma or metastasis. Surgical resection provides the only chance for cure for malignant pancreatic tumors. In some cases, surgical resection is performed because a malignant lesion is suspected, however, histopathological examinations eventually reveal a benign lesion. Here, we report the case of a 49-year-old woman, who was initially diagnosed with a neuroendocrine tumor of the pancreas with metastasis to the liver. The patient underwent distal pancreatectomy and atypical liver resection. Surprisingly, however, histopathological examination revealed an intrapancreatic accessory spleen (IPAS) of the pancreatic tail as well as liver hemangioma. This unique case report highlights the impact of extensive preoperative examinations to differentiate benign and malignant pancreatic lesions and, possibly, prevent patients from unnecessary surgery.

Update on pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are relatively rare tumors comprising 1-2% of all pancreas neoplasms. In the last 10 years our understanding of this disease has increased dramatically allowing for advancements in the treatment of pNETs. Surgical excision remains the primary therapy for localized tumors and only potential for cure. New surgical techniques using laparoscopic approaches to complex pancreatic resections are a major advancement in surgical therapy and increasingly possible. With early detection being less common, most patients present with metastatic disease. Management of these patients requires multidisciplinary care combining the best of surgery, chemotherapy and other targeted therapies. In addition to surgical advances, recently, there have been significant advances in systemic therapy and targeted molecular therapy.

Pancreatic neuroendocrine tumor with splenic vein tumor thrombus: A case report

INTRODUCTION

Pancreatic neuroendocrine tumors (PNET) are rare, often indolent malignancies. PNET are classified as functional or nonfunctional based on the secretion of hormones without a negative feedback loop; the latter account for up to 60% of PNET. Although PNET are associated with a better prognosis compared to pancreatic adenocarcinomas, they are often diagnosed in advanced stages, making them a significant source of morbidity for patients. Here we present a rare case of venous tumor thrombus arising from a nonfunctional PNET.

PRESENTATION OF CASE

A 44-year-old woman was referred for evaluation and treatment of a possible tail of pancreas PNET discovered during work-up for a 9 year history of intermittent subcostal pain. Previous endoscopic ultrasound with fine needle aspiration revealed a 3.5cm×3cm mass, with cytological diagnosis of neuroendocrine tumor. Patient was scheduled for laparoscopic distal pancreatectomy. During surgery the mass was found to encase the splenic vein leading the surgeon to perform an en bloc distal pancreatectomy and splenectomy. Pathologic analysis revealed a 1.8cm×5cm tumor thrombus lodged in the splenic vein.

DISCUSSION

Nonfunctional PNET usually present in advanced stages and can be associated with venous tumor thrombi. Preoperative imaging may not accurately predict the presence of venous tumor thrombi.

CONCLUSION

En bloc resection of primary tumor, involved organs and thrombus is the recommended treatment option and often results in long term survival. New multi-modality strategies are needed for detection of venous involvement in nonfunctional PNET to better assist with preoperative planning and counseling.

Pancreatic neuroendocrine tumor accompanied with multiple liver metastases

Pancreatic neuroendocrine tumor (P-NET) is rare and slow-growing. Current classifications predict its prognosis and postoperative recurrence. Curative resection is ideal, although often difficult, because over 80% of patients have unresectable multiple liver metastases and extrahepatic metastasis. Aggressive surgery for liver metastases is important to improve survival. Aggressive or cytoreductive surgery for liver metastases is indicated to reduce hormone levels and improve symptoms and prognosis. Liver transplantation was originally conceived as an ideal therapy for unresectable liver metastases. Unfortunately, there is no clear consensus on the role and timing of surgery for primary tumor and liver metastases. Surgeons still face questions in deciding the best surgical scenario in patients with P-NET with unresectable liver metastases.

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.

Advancements in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PanNETs) have increased in incidence in the USA over the last 20 years. Although PanNETs are often misconceived as being indolent tumors as they have a far more favorable prognosis over pancreatic adenocarcinoma, roughly 60-70% of patients have metastatic disease at the time of diagnosis due to presentation late in the disease process. While improvements in imaging modalities allow for early detection and better tumor localization, recent advancements in basic science, as well as surgical and medical management of PanNETs have further improved the prognosis. The mainstay of therapy for localized PanNETs is surgical intervention, which has become safer and is slowly shifting towards a more minimally invasive approach. However, the prognosis still remains relatively bleak for patients with unresectable disease. Fortunately, novel molecular targeted therapies, such as everolimus and sunitinib, have recently come into the limelight and have shown significant promise for the treatment of locally advanced and metastatic disease.

Clinical presentation, recurrence, and survival in patients with neuroendocrine tumors: results from a prospective institutional database

The rarity of neuroendocrine tumors (NET) has contributed to a paucity of large epidemiologic studies of patients with this condition. We characterized presenting symptoms and clinical outcomes in a prospective database of over 900 patients with NET. We used data from patient questionnaires and the medical record to characterize presenting symptoms, disease-free survival (DFS), and overall survival (OS). The majority of patients in this database had gastroenteropancreatic NET. The median duration of patient-reported symptoms before diagnosis was 3.4 months; 19.5% reported durations from 1 to 5 years, 2.5% from 5 to 10 years, and 2% >10 years. The median DFS among patients with resected small bowel NET or pancreatic NET (panNET) was 5.8 and 4.1 years respectively. After correcting for left truncation bias, the median OS was 7.9 years for advanced small bowel NET and 3.9 years for advanced panNET. Chromogranin A (CGA) above twice the upper limit of normal was associated with shorter survival times (hazard ratios 2.8 (1.9, 4.0) P<0.001) in patients with metastatic disease, regardless of tumor subtype. Our data suggest that while most NET patients are diagnosed soon after symptom onset, prolonged symptom duration before diagnosis is a prominent feature of this disease. Though limited to observations from a large referral center, our observations confirm the prognostic value of CGA and suggest that median survival durations may be shorter than that reported in other institutional databases.

Pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pancreatic NETs) are rare, low- to intermediate-grade neoplasms thought to arise from the pancreatic islets. Recent advances in pathology and our understanding of the biological behavior of this group of tumors has resulted in changes in their nomenclature and how we treat them. This review puts into perspective our current understanding of pancreatic NETs in terms of their incidence, pathology, and management.

Outcome of surgery for ileojejunal neuroendocrine tumors

PURPOSE

Neuroendocrine tumors (NET) of the ileum/jejunum are rare and may require different treatment options to provide long-term survival. The purpose of the study was to evaluate the outcome of surgery for ileojejunal NET.

METHODS

A database of patients that underwent surgery for ileojejunal NETs between 1999 and 2010 was retrospectively analyzed regarding the clinical characteristics, surgical therapy, survival and prognostic factors.

RESULTS

Only six of 97 patients with ileojejunal NET who underwent surgery had localized tumors (stage I/II), 29 had lymph node involvement (stage III) and 62 had distant metastases (stage IV) at the initial presentation. All stage I/II tumors were cured, in comparison to 69% of stage III and 0% of stage IV tumors (p = 0.01). Palliative surgery in combination with sequential multimodal treatment regimens resulted in a 5-year survival rate of 63% in patients with stage IV tumors. A multivariate analysis showed that incomplete resection (HR 2.87; CI 1.18-6.98; p = 0.04) and distant metastases (HR 5.39; 95% CI 1.23-23.57; p = 0.02) were associated with worse disease-specific survival.

CONCLUSIONS

Localized and regionally restricted ileojejunal NETs have an excellent prognosis after surgical treatment. Although stage IV tumors cannot be cured, an aggressive surgical approach in combination with medical or interventional treatment can provide long-term survival.

Surgery for a gastroenteropancreatic neuroendocrine tumor (GEPNET) in multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominantly inherited endocrine tumor syndrome characterized by tumor development in various endocrine organs such as the parathyroid, endocrine pancreas, anterior pituitary and adrenal cortex. The first extensive database for Asian patients with MEN1 was established by the MEN Consortium of Japan. Although the clinical features of Japanese patients with MEN1 are similar to those from Western countries, there are several characteristic differences between them. In particular, gastroenteropancreatic neuroendocrine tumor (GEPNET) is seen in approximately 60 % of patients with MEN1 in Japan. Although its development is the strongest prognostic factor in patients with MEN1, the characteristics of MEN1-associated GEPNET still remain unclear. This is especially true for the differences in clinical features of GEPNET with and without MEN1. Improved long-term survival is obtained by curative surgery for patients with MEN1-associated GEPNET. The current surgical indications are expanding even in patients with hepatic metastases because of the improved surgical outcome. This article reviews the clinical characteristics in these patients with a particular focus on surgery, diagnosis, surgical indications, surgical method, and surgical outcome.

Laparoscopic distal pancreatectomy: Up-to-date and literature review

Pancreatic surgery represents one of the most challenging areas in digestive surgery. In recent years, an increasing number of laparoscopic pancreatic procedures have been performed and laparoscopic distal pancreatectomy (LDP) has gained world-wide acceptance because it does not require anastomosis or other reconstruction. To date, English literature reports more than 300 papers focusing on LDP, but only 6% included more than 30 patients. Literature review confirms that LDP is a feasible and safe procedure in patients with benign or low grade malignancies. Decreased blood loss and morbidity, early recovery and shorter hospital stay may be the main advantages. Several concerns still exist for laparoscopic pancreatic adenocarcinoma excision. The individual surgeon determines the technical conduction of LDP, with or without spleen preservation; currently robotic pancreatic surgery has gained diffusion. Additional researches are necessary to determine the best technique to improve the procedure results.

Hepatic arterial embolization for the treatment of metastatic neuroendocrine tumors

Neuroendocrine tumors (NETs) have a high predilection for metastasizing to the liver and can cause severe debilitating symptoms adversely affecting quality of life. Although surgery remains the treatment of choice, many liver metastases are inoperable at presentation. Hepatic arterial embolization procedures take advantage of the arterial supply of NET metastases. The goals of these therapies are twofold: to increase overall survival by stabilizing tumor growth, and to reduce the morbidity in symptomatic patients. Patients treated with hepatic arterial embolization demonstrate longer progression-free survival and have 5-year survival rates of nearly 30%. The safety of repeat embolizations has also been proven in the setting of recurrent symptoms or progression of the disease. Despite not being curative, hepatic arterial embolization should be used in the management of NETs with liver metastases. Long-term survival is not uncommon, making aggressive palliation of symptoms an important component of treatment.