Histopathology of gastrointestinal neuroendocrine neoplasms

Update in the management of gastroenteropancreatic neuroendocrine tumors

Neuroendocrine neoplasms are a diverse group of neoplasms that can occur in various areas throughout the body. Well-differentiated neuroendocrine tumors (NETs) most often arise in the gastrointestinal tract, termed gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Although GEP-NETs are still uncommon, their incidence and prevalence have been steadily increasing over the past decades. The primary treatment for GEP-NETs is surgery, which offers the best chance for a cure. However, because GEP-NETs are often slow-growing and do not cause symptoms until they have spread widely, curative surgery is not always an option. Significant advances have been made in systemic and locoregional treatment options in recent years, including peptide-receptor radionuclide therapy with α and β emitters, somatostatin analogs, chemotherapy, and targeted molecular therapies.

Well-differentiated neuroendocrine tumors of the appendix: Diagnosis, differentials, and disease progression

Well-differentiated neuroendocrine tumors are the most common neoplasm of the appendix. They are graded and staged using World Health Organization and American Joint Committee on Cancer criteria, respectively. They may be invisible grossly or form rounded yellow nodules, sometimes in the appendiceal tip. They show classic neuroendocrine tumor features microscopically, forming nests and cords of monotonous cells with salt-and-pepper chromatin and amphophilic cytoplasm. They are positive for neuroendocrine markers by immunohistochemistry, but their molecular characteristics are not well defined. pT-category staging relies primarily on tumor size, though higher-stage cases may involve the subserosa or mesoappendix. Few entities enter the differential diagnosis, but lesions such as goblet cell adenocarcinoma, poorly differentiated neuroendocrine carcinoma, and mixed neuroendocrine-non-neuroendocrine neoplasm may be considered. Appendiceal neuroendocrine tumors may metastasize to regional lymph nodes, but farther spread is rare. The most consistently proven risk factor for such spread is tumor size, though different studies have proposed different cutoffs. Other potential risk factors include lymphovascular invasion and margin positivity. Tumors smaller than 1 cm can be treated by appendectomy, while hemicolectomy is recommended for tumors larger than 2 cm. Proper treatment for cases measuring 1-2 cm remains a matter of debate.

GASTRIC NEUROENDOCRINE TUMOR: WHEN SURGICAL TREATMENT IS INDICATED?

BACKGROUND

Gastric neuroendocrine tumors are a heterogeneous group of neoplasms that produce bioactive substances. Their treatment varies according to staging and classification, using endoscopic techniques, open surgery, chemotherapy, radiotherapy, and drugs analogous to somatostatin.

AIMS

To identify and review cases of gastric neuroendocrine neoplasia submitted to surgical treatment.

METHODS

Review of surgically treated patients from 1983 to 2018.

RESULTS

Fifteen patients were included, predominantly female (73.33%), with a mean age of 55.93 years. The most common symptom was epigastric pain (93.3%), and the mean time of symptom onset was 10.07 months. The preoperative upper digestive endoscopy (UDE) indicated a predominance of cases with 0 to 1 lesion (60%), sizing ≥1.5 cm (40%), located in the gastric antrum (53.33%), with ulceration (60%), and Borrmann III (33.33%) classification. The assessment of the surgical specimen indicated a predominance of invasive neuroendocrine tumors (60%), with angiolymphatic invasion in most cases (80%). Immunohistochemistry for chromogranin A was positive in 60% of cases and for synaptophysin in 66.7%, with a predominant Ki-67 index between 0 and 2%. Metastasis was observed in 20% of patients. The surgical procedure most performed was subtotal gastrectomy with Roux-en-Y reconstruction (53.3%). Tumor recurrence occurred in 20% of cases and a new treatment was required in 26.67%.

CONCLUSIONS

Gastric neuroendocrine tumors have a low incidence in the general population, and surgical treatment is indicated for advanced lesions. The study of its management gains importance in view of the specificities of each case and the need for adequate conduct to prevent recurrences and complications.

Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

BACKGROUND

The incidence of type I gastric neuroendocrine neoplasms (gNENs) has increased significantly over the past 50 years. Although autoimmune gastritis (AIG) increases the likelihood of developing gNENs, the exact incidence and prevalence of this association remain unclear.

AIM

To evaluate the incidence and prevalence of type I gNENs in a cohort of patients with a histological diagnosis of AIG.

METHODS

Patients with a histological diagnosis of AIG were enrolled between October 2020 and May 2022. Circulating levels of CgA and gastrin were assessed at enrollment. Included patients underwent regular endoscopic follow-up to detect gastric neoplastic lesions, enterochromaffin-like (ECL) cell hyperplasia, and the development of gNEN.

RESULTS

We included 176 patients [142 women (80.7%), median age 64 years, interquartile range (IQR) 53-71 years] diagnosed with AIG between January 1990 and June 2022. At enrollment. One hundred and sixteen patients (65.9%) had ECL hyperplasia, of whom, 29.5% had simple/linear, 30.7% had micronodular, and 5.7% had macronodular type. The median follow-up time was 5 (3-7.5) years. After 1032 person-years, 33 patients developed a total of 50 type I gNENs, with an incidence rate of 0.057 person-years, corresponding to an annual cumulative incidence of 5.7%. Circulating CgA levels did not significantly differ between AIG patients who developed gNENs and those who did not. Conversely, gastrin levels were significantly higher in AIG patients who developed gNENs [median 992 pg/mL IQR = 449-1500 vs 688 pg/mL IQR = 423-1200, P = 0.03]. Calculated gastrin sensitivity and specificity were 90.9% and 1.4%, respectively, with an overall diagnostic accuracy of 30% and a calculated area under the gastrin receiver operating characteristic curve (AUROC or AUC) of 0.53.

CONCLUSION

Type I gNENs are a significant complication in AIG. Gastrin's low diagnostic accuracy prevents it from serving as a marker for early diagnosis. Effective strategies for early detection and treatment are needed.

Virus-associated neuroendocrine cancers: Pathogenesis and current therapeutics

Neuroendocrine neoplasms (NENs) comprise malignancies involving neuroendocrine cells that often lead to fatal pathological conditions. Despite escalating global incidences, NENs still have poor prognoses. Interestingly, research indicates an intricate association of tumor viruses with NENs. However, there is a dearth of comprehension of the complete scenario of NEN pathophysiology and its precise connections with the tumor viruses. Interestingly, several cutting-edge experiments became helpful for further screening of NET for the presence of polyomavirus, Human papillomavirus (HPV), Kaposi sarcoma-associated herpesvirus (KSHV), Epstein Barr virus (EBV), etc. Current research on the neuroendocrine tumor (NET) pathogenesis provides new information concerning their molecular mechanisms and therapeutic interventions. Of note, scientists observed that metastatic neuroendocrine tumors still have a poor prognosis with a palliative situation. Different oncolytic vector has already demonstrated excellent efficacies in clinical studies. Therefore, oncolytic virotherapy or virus-based immunotherapy could be an emerging and novel therapeutic intervention. In-depth understanding of all such various aspects will aid in managing, developing early detection assays, and establishing targeted therapeutic interventions for NENs concerning tumor viruses. Hence, this review takes a novel approach to discuss the dual role of tumor viruses in association with NENs' pathophysiology as well as its potential therapeutic interventions.

Using 3D-bioprinted models to study pediatric neural crest-derived tumors

The use of three-dimensional (3D) bioprinting has remained at the forefront of tissue engineering and has recently been employed for generating bioprinted solid tumors to be used as cancer models to test therapeutics. In pediatrics, neural crest-derived tumors are the most common type of extracranial solid tumors. There are only a few tumor-specific therapies that directly target these tumors, and the lack of new therapies remains detrimental to improving the outcomes for these patients. The absence of more efficacious therapies for pediatric solid tumors, in general, may be due to the inability of the currently employed preclinical models to recapitulate the solid tumor phenotype. In this study, we utilized 3D bioprinting to generate neural crest-derived solid tumors. The bioprinted tumors consisted of cells from established cell lines and patient-derived xenograft tumors mixed with a 6% gelatin/1% sodium alginate bioink. The viability and morphology of the bioprints were analyzed via bioluminescence and immunohisto chemistry, respectively. We compared the bioprints to traditional twodimensional (2D) cell culture under conditions such as hypoxia and therapeutics. We successfully produced viable neural crest-derived tumors that retained the histology and immunostaining characteristics of the original parent tumors. The bioprinted tumors propagated in culture and grew in orthotopic murine models. Furthermore, compared to cells grown in traditional 2D culture, the bioprinted tumors were resistant to hypoxia and chemotherapeutics, suggesting that the bioprints exhibited a phenotype that is consistent with that seen clinically in solid tumors, thus potentially making this model superior to traditional 2D culture for preclinical investigations. Future applications of this technology entail the potential to rapidly print pediatric solid tumors for use in high-throughput drug studies, expediting the identification of novel, individualized therapies.

Tumour Heterogeneity and the Consequent Practical Challenges in the Management of Gastroenteropancreatic Neuroendocrine Neoplasms

Tumour heterogeneity is a common phenomenon in neuroendocrine neoplasms (NENs) and a significant cause of treatment failure and disease progression. Genetic and epigenetic instability, along with proliferation of cancer stem cells and alterations in the tumour microenvironment, manifest as intra-tumoural variability in tumour biology in primary tumours and metastases. This may change over time, especially under selective pressure during treatment. The gastroenteropancreatic (GEP) tract is the most common site for NENs, and their diagnosis and treatment depends on the specific characteristics of the disease, in particular proliferation activity, expression of somatostatin receptors and grading. Somatostatin receptor expression has a major role in the diagnosis and treatment of GEP-NENs, while Ki-67 is also a valuable prognostic marker. Intra- and inter-tumour heterogeneity in GEP-NENS, however, may lead to inaccurate assessment of the disease and affect the reliability of the available diagnostic, prognostic and predictive tests. In this review, we summarise the current available evidence of the impact of tumour heterogeneity on tumour diagnosis and treatment of GEP-NENs. Understanding and accurately measuring tumour heterogeneity could better inform clinical decision making in NENs.

Diagnosis, treatment, and current concepts in the endoscopic management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare tumors derived from the neuroendocrine cell system, which that have increased in incidence and prevalence in recent years. Despite improvements in radiological and metabolic imaging, endoscopy still plays a pivotal role in the number of GEP-NENs. Tumor detection, characterization, and staging are essential in management and treatment planning. Upper and lower gastrointestinal (GI) endoscopy is essential for correct localization of the primary tumor site of GI NENs. Endoscopic ultrasonography (EUS) has an important role in the imaging and tissue acquisition of pancreatic NENs and locoregional staging of GI neuroendocrine tumors. Correct staging and histological diagnosis have important prognostic implications. Endoscopic operating techniques allow the removal of small GI NENs in the early stage of mucosal or submucosal invasion of the intestinal wall. Preoperative EUS-guided techniques may help the surgeon locate small and deep tumors, thus avoiding formal pancreatic resections in favor of parenchymal-sparing surgery. Finally, locoregional ablative treatments have been proposed in recent studies with promising results in selected patients.

Ampullary Large-Cell Neuroendocrine Carcinoma, a Diagnostic Challenge of a Rare Aggressive Neoplasm: A Case Report and Literature Review

Ampullary large-cell neuroendocrine carcinomas (LCNECs) are extremely rare, and available data are limited on case reports. They present with jaundice, non-specific abdominal pain, or weight loss, imitating adenocarcinoma. Their incidence increases due to the improved diagnostic techniques. However, preoperative diagnosis remains challenging. We report the case of a 70-year-old man with a history of metabolic syndrome, cholecystectomy, and right hemicolectomy, presenting with jaundice. Laboratory results showed increased liver biochemistry indicators and elevated CA 19-9. Esophagogastroduodenoscopy revealed an ulcerative tumor on the ampulla of Vater, and the biopsy revealed neuroendocrine carcinoma. Although computed tomography (CT) detected enlarged regional lymph nodes, the positron emission tomography (PET) showed a hyperactive lesion only in this area. Pylorus-preserving pancreatoduodenectomy with R0 resection was performed. Pathologic evaluation of the 3.1 × 1.9 cm tumor revealed an LCNEC with immunohistochemical positivity at Synaptophysin, EMA, CD56, and cytokeratin CK8/18. The Ki-67 index was 45%. Two out of the nine dissected lymph nodes were occupied by the neoplasm. The patient was discharged home free of symptoms, and adjuvant chemotherapy with carboplatin + etoposide was initiated. A comprehensive review of the reported cases showed that the preoperative biopsy result was different from the final diagnosis in few cases, regarding the subtypes. Conventional radiology cannot identify small masses, and other methods, such as endoscopy, magnetic resonance cholangiopancreatography (MRCP), and FDG-PET scan, might aid the diagnosis. Diagnosis is based on histology and immunohistochemical markers of the surgical specimens. The treatment of choice is pancreatoduodenectomy, followed by adjuvant chemotherapy. However, recurrence is frequent, and the prognosis remains poor.

EUS-FNA Diagnosis of a Metastatic Adult Granulosa Cell Tumor in the Stomach

Granulosa cell tumors are uncommon ovarian neoplasms, predominantly of the adult type (AGCT). In this report, we present a rare case of a patient with metastatic AGCT to the stomach diagnosed with endoscopic ultrasound–guided fine-needle aspiration (EUS-FNA). A 61-year-old woman without a history of AGCT underwent both a vaginal and an abdominal ultrasound that showed a solid and cystic ovarian mass along with a solid mass in the gastric antral wall. Subsequently, an EUS-FNA was performed to assess the gastric lesion. Cytologic findings showed high cellularity, and the groups of neoplastic cells invaded the muscle layer of the stomach. Notably, these cells formed Call-Exner bodies, whereas some nuclei exhibited nuclear grooves. Immunohistochemistry was performed, revealing positivity for α-inhibin, calretinin, and CD56 in the neoplastic cells, whereas chromogranin, synaptophysin, CD117, and DOG1 were negative. The combination of clinical presentation, radiology, cytomorphology, and immunohistochemistry could facilitate the diagnosis of metastatic AGCT and the management of such patients.

A Modified T-stage Classification for Gastric Neuroendocrine Tumors

BACKGROUND

The eighth edition of the American Joint Committee on Cancer (AJCC) staging manual's TNM staging classification for gastric neuroendocrine tumors has been shown to have poor prognostic discriminability. The aim of present study was to propose a modified T-stage classification, and externally validate its performance in a separate population data registry.

METHODS

A modified T-stage classification with tumor size and extent of tumor invasion was generated from the National Cancer Database between 2004 and 2014 (n = 1249). External validation was performed using the Surveillance, Epidemiology, and End Results registry between 1973 and 2013 (n = 539).

RESULTS

In the National Cancer Database population, using the AJCC T-stage classification, the 5-y survival rates were 85.7%, 80.8%, 64.5%, and 46.1% in T1, T2, T3, and T4 patients respectively (P < 0.001). These rates were more contrasting with the modified T-stage (mT) classification at 87.0%, 78.2%, 59.0%, and 40.3% respectively (P < 0.001). When patients within each of the AJCC T stages were stratified by mT stages, significant survival heterogeneity was observed within each of the AJCC T2 to T4 stages (P < 0.01). Conversely, when mT stages were stratified by AJCC T stage, no survival difference was observed in any of the mT stages (P > 0.05). The same analyses were performed using Surveillance, Epidemiology, and End Results data, and all the observed results were validated.

CONCLUSION

The current AJCC T stage classification categorizes patients into groups with heterogenous prognosis, thus failing to serve as an effective staging tool. A modified T-stage classification demonstrated significantly improved stratification for patients with gastric neuroendocrine tumors.

Management of Primary Hepatopancreatobiliary and Ampulla Large Cell Neuroendocrine Carcinoma

Background: Large cell neuroendocrine carcinoma (LCNEC) of the liver, gallbladder, pancreas, and ampulla is rare and usually arises in case reports, and thus to date, no studies have well described the treatment options and outcomes of those patients. Methods: The data of 108 patients diagnosed as hepatopancreatobiliary and ampulla LCNEC between 2004 and 2015 were retrieved from the surveillance, epidemiology, and final results. Results: In the entire cohort, the median overall survival (OS) was 10 months. For nonmetastatic patients, the median OS was 32 months for surgery of the primary tumor alone (n = 17), 19 months for surgery of the primary tumor and adjuvant therapy (n = 19), and 1 month for nonsurgical treatment (n = 8). For metastatic patients, the median OS was 14 months for patients who received surgery of the primary tumor with and without adjuvant therapy (n = 16), 9 months for patients undergoing adjuvant treatment alone (n = 30), and 1 month for patients who had no treatment (n = 16). Multivariate analysis revealed that surgery of the primary tumor was an independent factor for improved survival. Conclusions: This disease offers a very poor prognosis despite aggressive treatment. Radical resection is the first choice for resectable tumors, whereas surgical resection of the primary tumor plus adjuvant therapy might represent a valid option for metastatic disease. However, further studies are needed to confirm this.

Neuroendocrine neoplasms of the gallbladder: early detection and surgery is key to improved outcome

PURPOSE

Neuroendocrine neoplasms (NENs) of the gallbladder are very rare. As a result, the classification of pathologic specimens from gallbladder NENs, currently classified as gallbladder neuroendocrine tumors (GB-NETs) and carcinomas (GB-NECs), is inconsistent and makes nomenclature, classification, and management difficult. Our study aims to evaluate the epidemiological trend, tumor biology, and outcomes of GB-NET and GB-NEC over the last 5 decades.

METHODS

This is a retrospective analysis of the SEER database from 1973 to 2016. The epidemiological trend was analyzed using the age-adjusted Joinpoint regression analysis. Survival was assessed with Kaplan-Meier analysis and Cox regression was used to assess predictors of poor survival.

RESULTS

A total of 482 patients with GB-NEN were identified. Mean age at diagnosis was 65.2 ± 14.3 years. Females outnumbered males (65.6% vs. 34.4%). The Joinpoint nationwide trend analysis showed a 7% increase per year from 1973 to 2016. The mean survival time after diagnosis of GB-NEN was 37.11 ± 55.3 months. The most common pattern of nodal distribution was N0 (50.2%) followed by N1 (30.9%) and N2 (19.2%). Advanced tumor spread (into the liver, regional, and distant metastasis) was seen in 60.3% of patients. Patients who underwent surgery had a significant survival advantage (111.0 ± 8.3 vs. 8.3 ± 1.2 months, p < 0.01). Cox regression analysis showed advanced age (p < 0.01), tumor stage (P < 0.01), tumor extension (p < 0.01), and histopathologic grade (p < 0.01) were associated with higher mortality.

CONCLUSION

Gallbladder NENs are a rare histopathological variant of gallbladder cancer that is showing a rising incidence in the USA. In addition to tumor staging, surgical resection significantly impacts patient survival, when patients are able to undergo surgery irrespective of tumor staging. Advanced age, tumor extension, and histopathological grade of the tumor were associated with higher mortality.

A Case of Profound Secretory Diarrhea Revealing 2 Primary Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are unusual neoplasms with a diverse spectrum of clinical presentations. There is a lack of literature on cases of 2 primary histologically distinct NETs. We report a case of a 40-year-old man who presented with chronic diarrhea. A colonoscopy was performed which discovered a rectal polyp, with pathology showing a well-differentiated NET. A subsequent somatostatin scan revealed a pancreatic tail mass. Biopsy showed a histologically distinct well-differentiated vasoactive intestinal peptide-producing NET. Given that pancreatic and rectal NETs come from different embryonic origins, the diagnosis of 2 primary NETs presents a unique case.

Diagnostic Immunostaining and Tumor Markers Predict the Prognosis of Esophageal Neuroendocrine Cell Carcinoma Patients

BACKGROUND

Esophageal neuroendocrine carcinoma (ENEC) has a poor prognosis, and predicting the prognosis by examining various markers may contribute to the determination of treatment strategies. Therefore, a multiple-institution retrospective study was performed to identify biomarkers using diagnostic immunohistochemistry and serum tumor markers that predict the prognosis of patients with ENEC.

METHODS

The results of immunohistochemical examination and serum tumor markers were extracted from the data of 141 ENEC patients at 39 institutions certified by the Japan Esophageal Society. The study then examined correlations between these data and prognosis or treatment effects.

RESULTS

The ENEC patients with positively for all expression of synaptophysin (Syn), chromogranin A (CgA), and CD56 had a significantly worse prognosis than the patients with other expression patterns. Additionally, surgery and chemoradiotherapy were significantly more effective treatments than chemotherapy for the patients who were not positive for all expressions of Syn, CgA, and CD56. In terms of serum tumor markers, the patients with a high neuron-specific enolase (NSE) value had a significantly worse prognosis than the patients with a normal NSE value, and complete response (CR) cases treated with chemotherapy were significantly fewer in the high-NSE group. The results of multivariate analysis demonstrated that high NSE levels were an independent poor prognostic factor for esophageal endocrine cell carcinoma.

CONCLUSION

This study showed that positivity for all expressions of Syn, CgA, and CD56, and a high NSE value were significantly worse prognostic factors for ENEC patients than other expression patterns and may be important prognostic biomarkers of ENEC.

Phosphoprotein-based biomarkers as predictors for cancer therapy

Disparities in cancer patient responses have prompted widespread searches to identify differences in sensitive vs. nonsensitive populations and form the basis of personalized medicine. This customized approach is dependent upon the development of pathway-specific therapeutics in conjunction with biomarkers that predict patient responses. Here, we show that Cdk5 drives growth in subgroups of patients with multiple types of neuroendocrine neoplasms. Phosphoproteomics and high throughput screening identified phosphorylation sites downstream of Cdk5. These phosphorylation events serve as biomarkers and effectively pinpoint Cdk5-driven tumors. Toward achieving targeted therapy, we demonstrate that mouse models of neuroendocrine cancer are responsive to selective Cdk5 inhibitors and biomimetic nanoparticles are effective vehicles for enhanced tumor targeting and reduction of drug toxicity. Finally, we show that biomarkers of Cdk5-dependent tumors effectively predict response to anti-Cdk5 therapy in patient-derived xenografts. Thus, a phosphoprotein-based diagnostic assay combined with Cdk5-targeted therapy is a rational treatment approach for neuroendocrine malignancies.

Biliary tract large cell neuroendocrine carcinoma: current evidence

Background

Primary neuroendocrine carcinomas of the gallbladder and biliary tract are rare, with pure large cell neuroendocrine carcinomas (LCNEC) being exceedingly rare and with a particularly poor prognosis.

Methods

We performed a review of published data on biliary tract large cell neuroendocrine carcinomas in PubMed.

Results

Preliminary search revealed over 2000 results but we found only 12 cases of pure large cell neuroendocrine carcinomas of biliary tract noted in literature to date. Because it commonly presents with non-specific symptoms of abdominal pain and jaundice, diagnosis is made after resection with histo-pathological and immunohistochemical analysis. These cancers are particularly aggressive with high recurrence rates, most often presenting with metastasis to regional lymph nodes and/or the liver resulting in a poor prognosis. Overall, complete surgical excision with systemic chemotherapy is the treatment mainstay. If the cancer is unresectable due to multiple metastases, medical management with systemic chemotherapy is the primary treatment modality.

Conclusion

The prognosis of hepatobiliary LCNEC remains poor with median survival of only 11 months from initial diagnosis. Studies focusing on high grade neuroendocrine carcinoma are needed to enhance our understanding of biology and therapeutics in this rare but aggressive cancer.

A case report on metastatic ileal neuroendocrine neoplasm to the breast masquerading as primary breast cancer: A diagnostic challenge and management dilemma

RATIONALE

Metastatic neuroendocrine neoplasms (NENs) to the breast are very rare entities comprising only 1% to 2% of all metastatic breast tumors. In this article, we describe a case of a neuroendocrine ileal neoplasm metastatic to breast and liver, with breast metastatic tumor to be the initial manifestation of the disease.

PATIENT CONCERNS

We herein report a rare case of a female patient admitted to our department with a palpable painful mass on her left breast.

DIAGNOSIS

The surgical and histological investigation revealed a metastatic neuroendocrine neoplasm to the breast originated from terminal ileum.

INTERVENTIONS

A left lumpectomy, right hemicolectomy, cholecystectomy, left hepatectomy along with liver metastasectomies (V, VI, VIII) plus radiofrequency ablation of lesions to the right liver lobe plus standard lymphadenectomy was performed.

OUTCOMES

Considering the advanced stage of the disease, the patient received an adjuvant therapy of somatostatin analog plus everolimus. Under the guidance of oncological consultation, patients follow-up with CT and MRI scan and clinical re-evaluations in the first 3 and 6 months, substantiates no evidence of recurrence and she presents herself asymptomatic.

LESSONS

An appropriate level of suspicion and selective immunohistochemistry in these cases, particularly where no prior history of a known primary neuroendocrine neoplasm occurs, may help to diagnose a previously undetected neuroendocrine tumor elsewhere in the body and provide guidance for the appropriate treatment selection.

Long term recurrence in primary liver neuroendocrine tumor: Report of a single case and review of literature

Primary liver neuroendocrine tumors (PLNETs) are rare tumors of the liver. They share some common characteristics with neuroendocrine tumors (NETs) of the extrahepatic bile ducts, such as slow rise, hormonal, and histological features. Nevertheless, they possess some peculiarities and the major feature is the difference in the metastatic potential between PLNETs and NETs. PLNETs have less metastatic potential compared with NETs, which is the main factor based on which differential diagnosis between the two groups is achieved. There exists few reports disease's long-term outcome, especially about the recurrences management. We report the case of a 52-year-old woman admitted to hospital for jaundice and presence of liver mass. She underwent extended right hepatectomy and subsequently, PLNET was revealed. After 9 years, a new mass was discovered in the remnant liver, far from the resection line, and was surgically removed. Histological examination confirmed a PLNET recurrence. The patient is alive and doing well after a year of surgery. We conducted a review of the literature on recurrent PLNETS. Five papers followed our inclusion criteria and included 10 patients. Clinical presentation was mostly nonspecific in included cases and no carcinoid syndrome was reported. Median overall survival and median disease-free survival periods were 22 and 5 months, respectively. The primary disease was treated with surgical resection in all the included cases and recurrent diseases were mostly treated with non-surgical techniques (mainly transarterial chemoembolization). In conclusion, more studies should be conducted in order to have significant data about this uncommon neoplasm. Finally, considering the lack of data on long-term outcome, a long and accurate follow-up should be considered.

Flushing Disorders Associated with Gastrointestinal Symptoms: Part 1, Neuroendocrine Tumors, Mast Cell Disorders and Hyperbasophila

Flushing is the subjective sensation of warmth accompanied by visible cutaneous erythema occurring throughout the body with a predilection for the face, neck, pinnae, and upper trunk where the skin is thinnest and cutaneous vessels are superficially located and in greatest numbers. Flushing can be present in either a wet or dry form depending upon whether neural-mediated mechanisms are involved. Activation of the sympathetic nervous system results in wet flushing, accompanied by diaphoresis, due to concomitant stimulation of eccrine sweat glands. Wet flushing is caused by certain medications, panic disorder and paroxysmal extreme pain disorder (PEPD). Vasodilator mediated flushing due to the formation and release of a variety of biogenic amines, neuropeptides and phospholipid mediators such as histamine, serotonin and prostaglandins, respectively, typically presents as dry flushing where sweating is characteristically absent. Flushing occurring with neuroendocrine tumors accompanied by gastrointestinal symptoms is generally of the dry flushing variant, which may be an important clinical clue to the differential diagnosis. A number of primary diseases of the gastrointestinal tract cause flushing, and conversely extra-intestinal conditions are associated with flushing and gastrointestinal symptoms. Gastrointestinal findings vary and include one or more of the following non-specific symptoms such as abdominal pain, nausea, vomiting, diarrhea or constipation. The purpose of this review is to provide a focused comprehensive discussion on the presentation, pathophysiology, diagnostic evaluation and management of those diseases that arise from the gastrointestinal tract or other site that may cause gastrointestinal symptoms secondarily accompanied by flushing. This review is divided into two parts given the scope of conditions that cause flushing and affect the gastrointestinal tract: Part 1 covers neuroendocrine tumors (carcinoid, pheochromocytomas, vasoactive intestinal polypeptide, medullary carcinoma of the thyroid), polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS), and conditions involving mast cells and basophils; while Part 2 covers dumping syndrome, mesenteric traction syndrome, rosacea, hyperthyroidism and thyroid storm, anaphylaxis, panic disorders, paroxysmal extreme pain disorder, and food, alcohol and medications.

A Practical Approach to the Classification of WHO Grade 3 (G3) Well-differentiated Neuroendocrine Tumor (WD-NET) and Poorly Differentiated Neuroendocrine Carcinoma (PD-NEC) of the Pancreas

High-grade neuroendocrine neoplasms (World Health Organization [WHO] G3) of the pancreas include both well-differentiated neuroendocrine tumor (WD-NET) and poorly differentiated neuroendocrine carcinoma (PD-NEC). According to the WHO classification scheme, the diagnosis of this group of tumors is based on both the histopathology of the tumor and the assessment of proliferation fraction. However, the former can be challenging due to the lack of well-defined histologic criteria, and the latter alone (ie, >20 mitoses/10 high-power fields or Ki67>20%) may not sufficiently distinguish WD-NETs from PD-NECs. Given the considerable differences in treatment strategies and clinical outcome, additional practical modalities are required to facilitate the accurate diagnosis of high-grade pancreatic neuroendocrine neoplasms. We examined 33 cases of WHO G3 neuroendocrine neoplasms of the pancreas and attempted to classify them into WD-NET, small cell PD-NEC (PD-NEC-SCC), and large cell PD-NEC (PD-NEC-LCC) or to designate them as "ambiguous" when an uncertain diagnosis was rendered by any of the observers or there was any disagreement in classification among the 3 observers. To simplify the interpretation, both PD-NEC-SCC and PD-NEC-LCC were considered together as PD-NECs in the final analysis. The initial approach was to assess microscopically a single morphologically challenging hematoxylin and eosin section from each case without the knowledge of Ki67 values, performed independently by 3 pathologists to assess the degree of diagnostic concordance, and then evaluate immunohistochemical staining for surrogate biomarkers of known genotypes of WD-NET and PD-NEC, respectively, and, lastly, complete a clinicopathologic review to establish a final definitive classification. Loss of DAXX or ATRX protein expression defined WD-NET, and abnormal p53, Rb, SMAD4 expression signified PD-NEC. When the chosen section displayed an element of WD histopathology, or other tumor sections contained WHO G1/G2 components, or there had been a prior established diagnosis of a primary WD-NET, the final diagnosis was rendered as a WD-NET with high-grade (G3) progression. If a component of conventional adenocarcinoma was present (in slides not seen in the initial review), the diagnosis was established as a combined adenocarcinoma and PD-NEC. All 3 pathologists agreed on the morphologic classification of 33% of the cases (6 WD-NET, 3 PD-NEC-SCC, and 2 PD-NEC-LCC), were conflicted on 2 cases between PD-NEC-SCC and PD-NEC-LCC, and disagreed or were uncertain on the classification for the remaining 20 cases (61%), which were therefore categorized as ambiguous. In the group of cases in which all pathologists agreed on the classification, the 6 WD-NET cases had either loss of DAXX or ATRX or had evidence of a WD-NET based on additional or prior pathology slides. The 7 PD-NEC cases had abnormal expression of p53, Rb, and/or SMAD4 or a coexisting adenocarcinoma. In the ambiguous group (n=20), 14 cases were established as WD-NETs, based upon loss of DAXX or ATRX in 7 cases and additional pathology evidence of high-grade progression from WD-NET in the other 7 cases; 5 cases were established as PD-NEC based upon abnormal expression of p53, Rb, and/or SMAD4; 1 case remained undetermined with normal expression of all markers and no evidence of entity-defining histologic findings in other slides. On the basis of the final pathologic classifications, the disease-specific survival was 75 and 11 months for the WD-NET and PD-NEC groups, respectively. Thus, we conclude that morphologic diagnosis of high-grade pancreatic neuroendocrine neoplasms is challenging, especially when limited pathologic materials are available, and necessitates better defined criteria. The analysis of both additional sections and prior material, along with an immunohistochemical evaluation, can facilitate accurate diagnosis in the majority of cases and guide the appropriate clinical management and prognosis.

Molecular alterations in sporadic pancreatic neuroendocrine microadenomas

BACKGROUND

Pancreatic neuroendocrine microadenomas (pNEMAs) are neuroendocrine tumors measuring <5 mm in diameter. They are considered the precursor of pancreatic neuroendocrine tumors (pNETs). The aim of this study was to investigate the immunohistochemical differences between pNEMA, pNET, and hyperplasia of pancreatic islet cells (HPIL) in patients with non-familial syndromes.

METHODS

We evaluated 21 pNEMAs, 19 HPILs, and 21 non-functional pNETs (10 G1 and 11 G2 cases) in patients with non-familial syndromes. Immunohistochemistry for tumor-associated markers death domain-associated protein (DAXX), alpha thalassemia/mental retardation X-linked (ATRX), cytokeratin 19 (CK19), bcl-2, and CD99 was performed.

RESULTS

DAXX was expressed in 95%, 71%, and 71% of HPIL, pNEMA, and pNET samples, respectively; the differences were not significant. ATRX expression in pNEMA and pNET was significantly lower than that in HPIL, whereas there was no significant difference between pNEMA and pNET (HPIL: 95%, pNEMA: 43%, and pNET: 52%). All HPIL and pNEMA cases were negative for bcl-2 and positive for CD99, whereas 29% of pNETs were positive for bcl-2 and 24% were negative for CD99. CK19 expression in HPIL was significantly lower than in pNEMA and pNET, although no significant difference was observed between pNEMA and pNET (HPIL: 5%, pNEMA: 57%, and pNET: 43%). Among G1 and G2 pNETs, CD99 was expressed in 50% of G1 pNETs but not in any G2 pNET cases.

CONCLUSION

Non-familial HPIL, pNEMA, and pNET patients exhibit distinct ATRX, CD99, CK19, and bcl-2 molecular profiles.

In1-ghrelin, a splice variant of ghrelin gene, is associated with the evolution and aggressiveness of human neuroendocrine tumors: Evidence from clinical, cellular and molecular parameters

Ghrelin system comprises a complex family of peptides, receptors (GHSRs), and modifying enzymes [e.g. ghrelin-O-acyl-transferase (GOAT)] that control multiple pathophysiological processes. Aberrant alternative splicing is an emerging cancer hallmark that generates altered proteins with tumorigenic capacity. Indeed, In1-ghrelin and truncated-GHSR1b splicing variants can promote development/progression of certain endocrine-related cancers. Here, we determined the expression levels of key ghrelin system components in neuroendocrine tumor (NETs) and explored their potential functional role. Twenty-six patients with NETs were prospectively/retrospectively studied [72 samples from primary and metastatic tissues (30 normal/42 tumors)] and clinical data were obtained. The role of In1-ghrelin in aggressiveness was studied in vitro using NET cell lines (BON-1/QGP-1). In1-ghrelin, GOAT and GHSR1a/1b expression levels were elevated in tumoral compared to normal/adjacent tissues. Moreover, In1-ghrelin, GOAT, and GHSR1b expression levels were positively correlated within tumoral, but not within normal/adjacent samples, and were higher in patients with progressive vs. with stable/cured disease. Finally, In1-ghrelin increased aggressiveness (e.g. proliferation/migration) of NET cells. Altogether, our data strongly suggests a potential implication of ghrelin system in the pathogenesis and/or clinical outcome of NETs, and warrant further studies on their possible value for the future development of molecular biomarkers with diagnostic/prognostic/therapeutic value.

Retrospective analysis of the clinicopathological characteristics of gastrointestinal neuroendocrine neoplasms

The aim of the present study was to analyze and summarize the clinicopathological characteristics and factors affecting prognosis for patients with gastrointestinal neuroendocrine neoplasms (GINENs). Retrospective analysis was conducted on the clinicopathological data of 74 patients who were diagnosed with GINEN, and immunohistochemical methods were used to detect the expression levels of relevant markers [synaptophysin (Syn), chromogranin A (CgA) and Ki-67]. Among the 74 cases with GINEN, there were 39 males and 35 females, with an average age of 56.9 years. There were 32 neoplasms in the rectum, 29 in the stomach, 6 in the colon, 2 in the small intestine and 5 in the appendix. All 74 cases underwent surgical resection. According to the World Health Organization Classification of Tumors of the Digestive System (2010), the diagnosis of the 74 cases showed 41 cases (55.4%) of neuroendocrine tumor (NET; 25 cases of G1 and 16 cases of G2), 21 cases (28.4%) of neuroendocrine carcinoma (NEC) and 12 cases (16.2%) of mixed adenoneuroendocrine carcinoma (MANEC). Additionally, 19 cases had metastasis to lymph nodes. During 10-34 months of follow-up, 15 patients had distant metastasis and 24 patients succumbed, and the accumulative survival rate in 1 or 2 years was 87.8 and 74.3%, respectively. Six factors, namely neoplasm size, depth of invasion, lymph node metastasis, distant metastasis, pathological type and the expression or lack of expression of CgA, significantly affected the survival time of patients. Definitive diagnosis of GINEN mainly relies on pathological diagnosis. GINENs with different histopathological types and grading have different clinicopathological characteristics and prognosis: NETs are mainly early lesions with a good prognosis, whereas NECs and MANECs have high malignancy and strong invasion with a worse prognosis.

An unusual case of a well-differentiated neuroendocrine tumour of the ileum with peritoneal carcinomatosis: a case report

Neuroendocrine tumours (NETs) are a family of neoplasms that come from neuroendocrine cells and express neural markers, such as synaptophysin or chromogranin A.

The current classifications of these tumours are presented by the WHO 2000 classification, based on histological parameters, and the WHO 2010 classification, based on the proliferative index, that divides the NETs into a neuroendocrine tumour of a low grade, neuroendocrine tumour of a intermediate grade and neuroendocrine carcinoma (NEC) of a high grade.

We are reporting a very rare case of a G1 low-grade neuroendocrine tumour (NET) of the ileum with a peritoneal carcinomatosis.

This case is challenging because the tumour expresses low proliferative index as G1 tumours, but it has an aggressive clinical behaviour such as node metastasis and peritoneal carcinomatosis.

The peritoneal carcinomatosis is not actually considered by the current classifications of NETs, so it is difficult to predict the prognosis of this patient.

Patterns of relapse in extrapulmonary small cell carcinoma: retrospective analysis of outcomes from two cancer centres

OBJECTIVES

We conducted a retrospective review of patients with extrapulmonary small cell carcinomas (EPSCCs) to explore the distribution, treatments, patterns of relapse and outcomes by primary site.

SETTING

We have reviewed the outcomes of one of the largest data sets of consecutive patients with EPSCC identified from two major cancer centres.

PARTICIPANTS

Consecutive patients with a histopathological diagnosis of EPSCC from the two institutions were retrospectively identified.

PRIMARY AND SECONDARY OUTCOME MEASURES

Outcomes were evaluated including stage at presentation, treatments given, sites of relapse, time to distant relapse, progression-free survival and overall survival (OS).

RESULTS

From a total 159 patients, 114 received first-line chemotherapy, 80.5% being platinum-based. Response rate was 48%. Commonest primary sites were genitourinary and gynaecological. 44% of patients presented with metastatic disease. 55.9% relapsed with liver the commonest site, whereas only 2.5% developed brain metastases. Median OS was 13.4 months for all patients, 7.6 months and 19.5 months for those with metastatic and non-metastatic disease, respectively. Gynaecological and head and neck patients had significantly better OS compared to gastrointestinal patients.

CONCLUSIONS

EPSCCs demonstrate high response rates to chemotherapy and high rates of distant metastases. Primary sites may influence prognosis, and survival is optimal with a radical strategy. Brain metastases are rare and we therefore do not recommend prophylactic cranial irradiation.

Neuroendocrine liver metastasis in gastric mixed adenoneuroendocrine carcinoma with trilineage cell differentiation: a case report

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare disease, which mostly occurs in the gastrointestinal tract and pancreas. Here we report a case of gastric MANEC with tri-lineage differentiation in which only the neuroendocrine component had metastasized to the liver. Liver and gastric masses were detected by abdominal computed tomography, and the preoperative relationship between liver and gastric masses was unknown. The histopathological analysis after operation confirmed the gastric mass to be MANEC, whereas the liver mass was actually the metastatic neuroendocrine component of the gastric MANEC. In the pathologic diagnosis, tri-lineage differentiation, including tubular adenocarcinoma, neuroendocrine carcinoma and squamous cell carcinoma was observed in the gastric MANEC tissues. The mitotic and Ki-67 labeling indexes of the resected tumor tissue were high, and thus, the tumor was classified as a grade G3 neuroendocrine carcinoma, which has a poor prognosis. Multiple low-density masses were found in the right lobe of the liver 2.5 months after operation.

Endoscopic biopsy in gastrointestinal neuroendocrine neoplasms: a retrospective study

BACKGROUND

Gastrointestinal neuroendocrine neoplasms (GI-NENs) are often located in the deep mucosa or submucosa, and the efficacy of endoscopic biopsy for diagnosis and treatment of GI-NENs is not fully understood.

OBJECTIVE

The current study analyzed GI-NENs, especially those diagnosed pathologically and resected endoscopically, and focused on the biopsy and cold biopsy forceps polypectomy (CBP) to analyze their roles in diagnosing and treating GI-NENs.

METHODS

Clinical data of all GI-NENs were reviewed from January 2006 to March 2012. Histopathology was used to diagnose GI-NENs, which were confirmed by immunohistochemistry.

RESULTS

67.96% GI-NENs were diagnosed pathologically by endoscopy. Only 26.21% were diagnosed pathologically by biopsies before treatment. The diagnostic rate was significantly higher in polypoid (76.47%) and submucosal lesions (68.75%), than in ulcerative lesions (12.00%). However, biopsies were only taken in 56.31% patients, including 51.52% of polypoid lesions, 35.56% of submucosal lesions and 100.00% of ulcerative lesions. Endoscopic resection removed 61.76% of GI-NENs, including six by CBP, 14 by snare polypectomy with electrocauterization, 28 by endoscopic mucosal resection (EMR) and 15 by endoscopic submucosal dissection (ESD). 51.52% polypoid GI-NENs had infiltrated the submucosa under microscopic examination. CBP had a significantly higher rate of remnant (33.33%) than snare polypectomy with electrocauterization, EMR and ESD (all 0.00%).

CONCLUSIONS

Biopsies for all polypoid and submucosal lesions will improve pre-operative diagnosis. The high rate of submucosal infiltration of polypoid GI-NENs determined that CBP was inadequate in the treatment of GI-NENs. Diminutive polypoid GI-NENs that disappeared after CBP had a high risk of remnant and should be closely followed up over the long term.

Primary hepatic neuroendocrine carcinoma: MR imaging findings including preliminary observation on diffusion-weighted imaging

PURPOSE

To investigate MR imaging findings of primary hepatic neuroendocrine carcinoma (PHNEC) including preliminary observations on diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

MR images of eight patients with pathologically confirmed PHNEC were retrospectively analyzed. The morphological characteristics and dynamic enhancement patterns were evaluated.

RESULTS

One case showed a well-defined solitary nodule with homogenous hypointensity on T1-weighted imaging (T1WI) and hyperintensity on T2-weighted imaging (T2WI) and DWI. The remaining seven cases appeared as well-defined dominant masses with multiple satellite nodules. The dominant masses demonstrated heterogeneous hypointensity on T1WI and hyperintensity on T2WI, which all appeared as a marked enhancement at arterial phase and rapid washout at portal venous phase. Six cases demonstrated rim-like enhancement at equilibrium phase. The satellite lesions showed heterogeneous hypointensity on T1WI and marked hyperintensity on T2WI with variable enhancements, such as homogeneous, rim-like enhancement. All the dominant masses and satellite nodules appeared as markedly hyperintensity and reduced apparent coefficient (ADCs) values on DWI. The mean ADC value of the tumors was significantly lower than that of surrounding liver parenchyma (1.02 ± 0.57 vs. 2.24 × 10(-3) mm(2)/s, p = 0.000).

CONCLUSION

PHNECs typically appear as a large dominant hypervascular mass accompanied by satellite nodules, with rapid washout and capsular enhancement on dynamic MR imaging and restricted diffusion on DWI.

Small cell type neuroendocrine carcinoma colliding with squamous cell carcinoma at esophagus

Collision tumor is an extremely rare tumor which defined as the concrescence of two distinct primaries neoplasms. We report here a case of collision tumor at lower third esophagus composed of small cell type neuroendocrine carcinoma (NEC), which is an very rare, highly aggressive and poorly prognostic carcinoma and squamous cell carcinoma (SqCC). In our case, pathologically, the small cell carcinoma display the characteristic of small, round, ovoid or spindle-shaped tumor cells with scant cytoplasm, which colliding with a moderately differentiated squamous cell carcinoma. Immunohistochemical staining demonstrated positive activities for CD56, synaptophysin, 34βE12, CK 5/6, ki-67 (70%-80%), but negative for CD99, chromogranin A, and TTF-1. Accurate diagnosis was made base on these findings.

An expression signature of the angiogenic response in gastrointestinal neuroendocrine tumours: correlation with tumour phenotype and survival outcomes

Background:

Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are heterogeneous with respect to biological behaviour and prognosis. As angiogenesis is a renowned pathogenic hallmark as well as a therapeutic target, we aimed to investigate the prognostic and clinico-pathological role of tissue markers of hypoxia and angiogenesis in GEP-NETs.

Methods:

Tissue microarray (TMA) blocks were constructed with 86 tumours diagnosed from 1988 to 2010. Tissue microarray sections were immunostained for hypoxia inducible factor 1α (Hif-1α), vascular endothelial growth factor-A (VEGF-A), carbonic anhydrase IX (Ca-IX) and somatostatin receptors (SSTR) 1–5, Ki-67 and CD31. Biomarker expression was correlated with clinico-pathological variables and tested for survival prediction using Kaplan–Meier and Cox regression methods.

Results:

Eighty-six consecutive cases were included: 51% male, median age 51 (range 16–82), 68% presenting with a pancreatic primary, 95% well differentiated, 51% metastatic. Higher grading (P=0.03), advanced stage (P<0.001), high Hif-1α and low SSTR-2 expression (P=0.03) predicted for shorter overall survival (OS) on univariate analyses. Stage, SSTR-2 and Hif-1α expression were confirmed as multivariate predictors of OS. Median OS for patients with SSTR-2+/Hif-1α-tumours was not reached after median follow up of 8.8 years, whereas SSTR-2-/Hif-1α+ GEP-NETs had a median survival of only 4.2 years (P=0.006).

Conclusion:

We have identified a coherent expression signature by immunohistochemistry that can be used for patient stratification and to optimise treatment decisions in GEP-NETs independently from stage and grading. Tumours with preserved SSTR-2 and low Hif-1α expression have an indolent phenotype and may be offered less aggressive management and less stringent follow up.