Mixed Adeno-neuroendocrine Carcinoma: An Aggressive Clinical Entity

Mixed neuroendocrine and adenocarcinoma of gastrointestinal tract: A complex diagnosis and therapeutic challenge

In this editorial we comment on the manuscript describing a case of adenocarcinoma mixed with a neuroendocrine carcinoma of the gastroesophageal junction. Mixed neuroendocrine and non-neuroendocrine neoplasms of the gastrointestinal system are rare heterogeneous group of tumors characterized by a high malignant potential, rapid growth, and poor prognosis. Due to the rarity of these cancers, the standard therapy is poorly defined. The diagnosis of these tumors is based on combination of morphological features, immunohistochemical and neuroendocrine and epithelial cell markers. Both endocrine and epithelial cell components can act independently of each other and thus, careful grading of each component separately is required. These cancers are aggressive in nature and the potential of each component has paramount importance in the choice of treatment and response. Regardless of the organ of origin, these tumors portend poor prognosis with increased proportion of neuroendocrine component. Multidisciplinary services and strategies are required for the management of these mixed malignancies to provide the best oncological outcomes. The etiopathogenesis of these mixed tumors remains obscure but poses interesting question. We briefly discuss a few salient points in this editorial.

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a heterogeneous group of malignant neoplasms that can settle in the gastroenteropancreatic tract. They are composed of a neuroendocrine (NE) and a non-NE component in at least 30% of each tumour. The non-NE component can include different histological combinations of glandular, squamous, mucinous and sarcomatoid phenotypes, and one or both of the components can be low-or high grade malignant. Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion, and the lack of specific clinical trials is the main reason why their management is difficult. The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data. It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that, due to their low incidence, will require long recruitment periods.

Gastric mixed neuroendocrine non-neuroendocrine neoplasms

The uncommon tumour known as gastric mixed neuroendocrine-non-neuroendocrine neoplasms (G-MiNENs) is made up of parts of neuroendocrine carcinoma and adenocarcinoma. The biological and clinical features are different from those of gastric adenocarcinoma. Their pathophysiology, diagnostic standards, and clinical behaviour have all been the subject of lengthy debates, and their nomenclature has undergone multiple changes. Its emergence has created new challenges in the classification and diagnosis of gastric tumours. This review will update information on the topic, covering molecular aspects, diagnostic criteria, treatment, and prognostic factor discovery. It will also provide a historical context that will aid in understanding the evolution of the idea and nomenclature of mixed gastric tumours. Additionally, it will provide the reader a thorough understanding of this difficult topic of cancer that is applicable to real-world situations.

Mixed adenoneuroendocrine carcinoma originating from the appendix and colorectum: a comparative analysis of a large population-based database

PURPOSE

As a rare gastrointestinal neoplasm, the demographic, clinicopathological, and prognostic characteristics of mixed adenoneuroendocrine carcinoma (MANEC) remain unclear. The purpose of this study was to evaluate its biological features, survival outcome, and prognostic factors.

METHODS

From the Surveillance, Epidemiology, and End Results (SEER) database, we retrospectively reviewed clinicopathological and survival data of 513 patients who were histopathologically diagnosed with MANEC of the appendix and colorectum bettween 2004 and 2015. The clinicopathological features and survival outcomes of MANEC located at different anatomical locations were compared, and predictive factors for cancer-specific survival (CSS) and overall survival (OS) were assessed.

RESULTS

In terms of anatomical distribution of MANEC, the appendix (64.5%, 331/513) was more frequently involved, followed by colon (28.1%, 144/513) and rectum (7.4%, 38/513). The MANEC at different anatomical locations had a distinct clinicopathological characteristic, and colorectal MANEC was significantly associated with more aggressive biological features. The survival outcomes of appendiceal MANEC were significantly better than that of colorectal MANEC (3-year CSS rate 73.8% vs 59.4%, P = 0.010; 3-year OS 69.2% vs 48.3%, P < 0.001). In addition, hemicolectomy had a better survival benefit than appendicectomy for patients with appendiceal MANEC, regardless of lymph node metastasis (P < 0.05). Tumor location, histology grade III, tumor size > 2 cm, T3-T4 stage, lymph node metastasis, and distant metastasis were independent prognostic factors for patients with MANEC.

CONCLUSIONS

Tumor location had an important prognostic significance for MANEC. As an uncommon clinical entity, colorectal MANEC had more aggressive biological features and worse prognosis than its appendiceal counterpart. The standard surgical procedure and clinical management strategy for MANEC need to be established.

Incidence, survival, and prognostic factors for patients with gastrointestinal mixed neuroendocrine non-neuroendocrine neoplasms: a SEER population-based study

BACKGROUND

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a group of rare tumors with limited research currently available. This study aimed to analyze the incidence, survival, and prognostic factors of gastrointestinal MiNENs.

METHODS

We included data from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2019. We compared the clinicopathologic characteristics and survival rates between MiNENs and neuroendocrine tumors (NETs), and calculated the incidence of MiNENs. We utilized univariate and multivariate Cox analysis to assess independent factors of prognosis and established a nomogram to predict 1-, 2-, and 3-year cancer-specific survival (CSS). Calibration and receiver operating characteristic (ROC) curves were drawn to validate the accuracy and reliability of the model. Decision curve analysis (DCA) was used to assess the clinical utility of the model.

RESULTS

Patients with gastrointestinal MiNENs had a poorer prognosis than those with NETs. The overall incidence of gastrointestinal MiNENs has been increasing annually. Multivariate Cox regression analysis revealed that tumor size, lymph node metastasis, distant metastasis, and surgery were independent risk factors for CSS in MiNENs patients. Based on these risk factors, the 1-, 2-, and 3-year CSS nomogram model for MiNENs patients was established. Calibration, ROC, and DCA curves of the training and validation sets demonstrated that this model had good accuracy and clinical utility.

CONCLUSION

Gastrointestinal MiNENs are rare tumors with an increasing incidence rate. The nomogram model is expected to be an effective tool for personalized prognosis prediction in MiNENs patients, which may benefit clinical decision-making.

Digestive MiNENs: Could histological classification and molecular characterization drive clinical outcome and therapeutic approach?

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are epithelial neoplasms in which neuroendocrine and non-neuroendocrine discrete components are combined, each of which constitutes ≥ 30% of the neoplasm. The finding of an additional neuroendocrine component seems to characterize the tumor's biological behavior. Few studies have proved MiNENs histogenetic and molecular characterization, and the development of molecular markers for more accurate classification of MiNENs represents a clinical need. However, a common origin of the neuroendocrine and non-neuroendocrine components from a pluripotent cancer stem cell could be suggested. The optimal clinical management of MiNENS is largely unknown. Whenever feasible, curative-intent resection should be performed for localized disease; in advanced disease, the treatment should be targeted to the component responsible for the metastatic spreading. This paper provides a revision of the current knowledge on MiNENs, focusing on available evidence about their molecular characterization to suggest a prognostic stratification of these rare forms.

Discussion on the benefits of different treatment strategies in elderly and non-elderly patients with appendix MiNEN: a retrospective study based on SEER database

PURPOSE

To investigate the benefits of surgery alone and postoperative chemotherapy in elderly and non-elderly patients with appendiceal mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) and analyze the factors affecting the prognosis of patients with MiNEN of the appendix.

METHODS

Based on the Surveillance, Epidemiology, and End Results database (SEER) of the National Cancer Institute of the USA, 389 patients with appendiceal MiNENs from 2000 to 2016 were collected. All patients were distributed in the elderly group (≥ 60 years old) and the non-elderly group (< 60 years old) according to their age. The prognosis of the two groups of patients who received simple surgery and postoperative chemotherapy was analyzed and compared. The two treatment methods of the two tranches were matched by propensity score matching method. The effect of different treatment ways on the prognosis of sick persons was compared. The survivorship curves were painted by the Kaplan Meier method, log rank test was used to analyze the subsistence discrepancy of each group, and COX proportional risk model was used to analyze the factors affecting the prognosis of patients with appendiceal MiNENs.

RESULTS

No matter the overall survival rate (OS) or cancer-specific mortality (CSM) of the two treatment schemes, the prognosis of patients in the only surgery group was meaningfully higher than that in the postoperative chemotherapy group, with statistically significant difference in component comparison (χ² = 16.496, χ² = 16.860, P < 0.001). After propensity score matching of patients in each group, there was no striking discrepancy in the OS of patients in the only surgery group compared with those in the postoperative chemotherapy group, regardless of whether they were elderly patients or non-elderly patients (χ² = 3.205, χ² = 1.521, all P > 0.05), the CSM consequences are fitting in with the OS. The consequences of the multivariate COX regression model showed that age (≥ 60 years old), sex (female), high histological grade, and lymph node positive were all the influencing factors for the poor OS of patients with MiNEN; the CSM results are consistent with the OS.

CONCLUSION

For patients with appendix MiNEN, whether elderly or non-elderly patients (especially for non-elderly patients), surgical treatment may be a better choice.

Management of Appendix Neuroendocrine Neoplasms: Insights on the Current Guidelines

Appendiceal neuroendocrine neoplasms (ANENs) usually present as incidental findings at the time of appendectomy for acute appendicitis. They are rare, accounting for only 0.5-1% of intestinal neoplasms; they are found in 0.3-0.9% of all appendectomy specimens. They are usually sporadic tumors. There are several histological types including well-differentiated neuroendocrine tumors (NETs), poorly differentiated neuroendocrine carcinomas (NECs), and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). Histologic differentiation and the grade of well-differentiated NETs correlate with clinical behavior and prognosis. Management varies based on differentiation, aggressiveness, and metastatic potential. There is debate about the optimal surgical management for localized appendiceal NETs that are impacted by many factors including the tumor size, the extent of mesoappendiceal spread, lymphovascular invasion and perineural involvement. In addition, the data to guide therapy in metastatic disease are limited due to the paucity of these tumors. Here, we review the current advances in the management of ANENs within the context of a multidisciplinary approach to these tumors.

A rare case of poorly differentiated mixed neuroendocrine-nonneuroendocrine tumor of the caecum with long term survival: A case report

A 59-year-old woman presented with flushing attacks accompanied by tachycardia and hypotension, which lasted approximately 30 to 60 minutes, underwent 18 years ago a gastrointestinal tumor resection. The histologic examination revealed a poorly differentiated mixed neuroendocrine/adenocarcinoma located in the caecum with regional metastases. Postoperatively, the patient received combined chemotherapy of 5-fluorouracil with interferon for six months and since has remained asymptomatic. Her examination revealed positivity for chromogranin A (CgA) and a-Fetoprotein (aFP) (580 ng/24 h, normal range 27–94, and 10 IU/mL, normal range 0–6, respectively). Urinary 5-hydroxy indole acetic acid excretion was remarkably high (41.8 mg/24 h, normal range 2–10 mg/24 h). An abdominal Magnetic Resonance Imaging scan revealed multiple focal loci in the liver whose histological examination revealed a carcinoid tumor confirmed by an Octreoscan. Additional uptake was noted on the right shoulder and the right sternum-clavicle joint confirmed by Tc-99m MDP scan. The patient received somatostatin analogue therapy followed by long-acting release octreotide analogue therapy (30 mg/month) showing a partial improvement of relevant biomarkers. Two years later, carcinoid syndrome symptoms reappeared and due to the tumors expression of somatostatin receptors the patient received peptide receptor radionuclide therapy with 177Lu-DOTATATE that resulted in both clinical and biochemical improvements.

Goblet Cell Adenocarcinoma of the Appendix: A Systematic Review and Incidence and Survival of 1,225 Cases From an English Cancer Registry

Background

Goblet cell adenocarcinoma (GCA) of the appendix is a rare and aggressive tumour with varying nomenclature and classification systems. This has led to heterogeneity in published data, and there is a lack of consensus on incidence, survival, and management.

Methods

We provide an overview of GCA with a comprehensive systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and a retrospective analysis of all cases recorded in the English National Cancer Registration and Analysis Service database between 1995 and 2018. The Kaplan–Meier estimator was used to calculate overall survival, and Cox proportional hazards regression was used to identify prognostic factors.

Results

The systematic review demonstrated an incidence of 0.05–0.3 per 100,000 per year among North American registry studies. The 1-, 3-, and 5-year survival rate was 95.5%, 85.9%–87.6%, and 76.0%–80.6%, respectively. Age, stage, and grade were identified as prognostic factors for survival. Our analysis included 1,225 cases. Age-standardised incidence was 0.0335 per year in 1995 and gradually rose to 0.158 per year in 2018. The 1-, 3-, and 5-year survival rate was 90.0% [95% confidence interval (95% CI): 85.4–94.0], 76.0% (95% CI: 73.8–80.9), and 68.6% (95% CI: 65.9–72.2), respectively. On univariate Cox regression analyses, female sex, stage, and grade were associated with worse overall survival. On multivariate analysis, only stage remained a statistically significant prognostic factor.

Conclusions

GCA of the appendix is rare, but incidence is increasing. We report a lower incidence and survival than North American registry studies. Higher stage was associated with decreased survival. Further prospective studies are required to establish optimal management.

Mixed neuroendocrine-nonneuroendocrine neoplasm of the ampulla: Four case reports

BACKGROUND

Mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN) is a rare tumor that occurs in the gastrointestinal tract and pancreas, usually composed of adenocarcinoma and neuroendocrine carcinoma. MiNEN occurring in ampulla is even rarer. We report 4 cases of MiNEN in ampulla, combined with literature review to summarize the clinical features and treatment of the disease, in order to improve the understanding of the disease.

CASE SUMMARY

A retrospective analysis was performed in 4 cases of MiNEN of the ampulla diagnosed by pathology from 2014 to 2021. The 4 patients were all male, aged 67-81 years (average 72.25 years). Among them, 2 patients had jaundice, 1 patient had abdominal pain, and 1 patient had jaundice with abdominal pain as the first symptom. All 4 patients underwent enhanced CT or MRI, which all indicated that the tumors were located in the ampulla. Two patients underwent duodenoscopy, and a biopsy revealed ampullary adenocarcinoma. All 4 patients underwent radical pancreaticoduodenectomy. Four cases were followed up: One patient developed severe complications after the operation, his condition deteriorated, and he survived for 1 mo. In the other 3 patients, tumor recurrence was observed during follow-up, and 2 of them survived for 29 mo and 22 mo respectively. One case survived and is still being followed up.

CONCLUSION

MiNEN of the ampulla are extremely rare, lacking typical clinical symptoms and imaging features, and are usually diagnosed after postoperative histopathological and immunohistochemical examinations. The main treatment is radical surgical resection, which can be combined with chemotherapy. The best method of diagnosis and treatment needs further research.

The Landmark Series: Appendiceal Primary Peritoneal Surface Malignancy

Appendiceal primary peritoneal surface malignancies are rare and include a broad spectrum of pathologies ranging from indolent disease to aggressive disease. As such, the data that drive the management of appendiceal peritoneal surface malignancies is generally not based on prospective clinical trial data, but rather consists of level 1 data based on retrospective studies and high-volume institutional experiences. Complete surgical debulking typically offers the best chance for long-term survival. This review highlights the landmark articles on which management of primary appendiceal peritoneal surface malignancies are based.

Mixed adenoneuroendocrine carcinomas of stomach and ampulla of vater after curative-intent resection: a single center cases series

Background

Mixed adenoneuroendocrine carcinoma is a rare clinical manifestation, especially in the gastric and ampullary. The purpose of this study was to investigate the clinicopathological features and prognosis of mixed adenoneuroendocrine carcinoma in the gastric and ampullary and summarize related treatment suggestions.

Methods

In all, 32 cases of mixed adenoneuroendocrine carcinoma in the gastric and ampullary that were diagnosed from resected specimens were analyzed from 2009 to 2015. The corresponding demographic, clinicopathological and survival data were retrospectively reviewed.

Results

The 1-year, 3-year and 5-year survival rates were 78.1%, 28.1 and 9.4%, respectively, and the median overall survival was 28.0 months. In all, 75.0% (24/32) had lymph node metastasis at the time of initial diagnosis. A multivariate analysis revealed that TNM stage (HR 6.444 95%CI 1.477–28.121 P = 0.013), lymph nodes metastasis (HR10.617 95%CI 1.409–79.997 P = 0.022), vascular invasion (HR 5.855 95%CI 1.719–19.940 P = 0.005), grade of the adenocarcinoma component (HR 3.876 95%CI 1.451–10.357 P = 0.007) and CD56 positivity (HR 0.265 95%CI 0.100–0.705 P = 0.008) were independent predictors of overall survival.

Conclusions

Mixed adenoneuroendocrine carcinoma is an aggressive clinical entity with a poor prognosis. Taking both the neuroendocrine component and the adenocarcinoma component into consideration of optimal treatment is strongly recommended.

Chemotherapy in the treatment of different histological types of appendiceal cancers: a SEER based study

Background

Due to its rarity and high heterogeneity, neither established guidelines nor prospective data are currently available for using chemotherapy in the treatment of appendiceal cancer. This study was to determine the use of chemotherapy and its potential associations with survival in patients with different histological types of the cancer.

Methods

Patients with histologically different appendiceal cancers diagnosed during 1998–2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The role and effect of chemotherapy were examined in the treatment of the disease. The Kaplan-Meier method was applied to construct survival curves and significance was examined by Log-rank test. Cox proportional hazard models were used to analyze the impact of chemotherapy and other variables on survival in these patients.

Results

A total of 8733 appendiceal cancer patients were identified from the database. Chemotherapy was administrated at highly variable rates in different histological types of appendiceal cancer. As high as 64.0% signet ring cell carcinoma (SRCC), 46.4% of mucinous adenocarcinomas (MAC), 40.6% of non-mucinous adenocarcinoma (NMAC) and 43.9% of mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) were treated with chemotherapy, whereas only 14.7% of goblet cell carcinoma (GCC), 5% neuroendocrine tumors (NETs) and 1.6% carcinomas (NEC) received chemotherapy. In all patients combined, chemotherapy significantly improved overall survival during the entire study period and cancer-specific survival was improved during in cases from 2012–2016. Further multivariate analysis showed that both cancer-specific and overall survival was significantly improved with chemotherapy  in patients with MAC, NMAC and SRCC, but not for patients with GCC, MiNENs, NETs and NECs. Number (> 12) of lymph node sampled was associated with survival of patients with most histological types of cancer under study. Other prognostic factors related to individual histological types were identified.

Conclusions

Chemotherapy is administrated at highly variable rates in different histological types of appendiceal cancer. Efficacy of chemotherapy in the treatment of these cancers has been improved in recent years and is significantly associated with better survival for patients with NMAC, MAC, and SRCC. Adequate lymph node sampling may result in a survival benefit for most of these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08502-3.

Palatine tonsil metastasis of cecal mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN): A unique case

This case demonstrates the importance of understanding that patients with malignant neoplasms may exhibit metastases in unexpected sites and illustrates the necessity of a thorough clinical examination and pathologic correlation.

Clinicopathological features and lymph node and distant metastasis patterns in patients with gastroenteropancreatic mixed neuroendocrine-non-neuroendocrine neoplasm

Objective

Owing to its rarity and heterogeneity, the biological behavior and optimal therapeutic management of mixed neuroendocrine‐non‐neuroendocrine neoplasm (MiNEN) have not been established. Herein, we aimed to evaluate the clinicopathological characteristics and metastatic patterns of MiNEN.

Methods

Continuous clinicopathological data of MiNEN patients treated at our hospital were retrospectively collected and analyzed.

Results

This study had enrolled 169 patients since January 2010 to January 2020. Pathological components were assessed in 129 patients with MiNEN (76.3%), and a focal (non‐)neuroendocrine component was observed in 40 patients (23.7%; <30% of the tumor). Among the enrolled patients, 80 underwent surgical removal of the primary tumor and lymph nodes (LNs), and 34 with distant metastasis underwent biopsy of both primary tumor and metastatic lesions. In patients with LN metastasis, 68.8% (55/80) exhibited a pure component of either neuroendocrine (NE) or adenocarcinoma/squamous carcinoma (AS) in metastatic LNs, while 20% (16/80) showed different components in different LNs, and only 11.2% (9/80) exhibited both NE and AS components in the same LN. In patients with distant metastases, 26.5% (9/34) possessed coexisting NE and AS components in the distant metastases, 70.6% (24/34) were regarded as a pure NE component, and 2.9% (1/34) were comprised of a pure AS component.

Conclusion

Lymph node and distant metastases exhibited distinct metastatic patterns in patients with MiNEN. The major pathological component in regional LNs may have influenced the proportion of the two components within the primary tumor, but distant metastases were dominated by the NE component.

Mixed adenoneuroendocrine carcinoma (MANEC) of the lower gastrointestinal tract: A systematic review with Bayesian hierarchical survival analysis

BACKGROUND

Mixed adeno-neuroendocrine carcinomas (MANEC) are a subgroup of mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) described as mixed neoplasms containing dual neuroendocrine and non-neuroendocrine components. The aim of this study was to appraise the prevalence of MANEC in the lower gastrointestinal (GI) tract and provide reliable estimates of survival.

METHOD

A systematic review was undertaken in accordance with PRISMA guidelines using PubMed, Embase, Cochrane Library of Systematic Review, Web of Science, and Scopus databases, and a Bayesian hierarchical survival pooled analysis was performed.

RESULTS

Of 182 unique records identified, 71 studies reporting on 752 patients met the inclusion criteria. Mean age was 64.2 ± 13.6, with a male-to-female ratio of 1.25. Overall, 60.3% of MANEC were located in the appendix, 29.3% in the colon, and 10.4% in the anorectum. More than a quarter (29%) of patients had stage IV disease at diagnosis, with higher prevalence in appendiceal than colonic and anorectal primaries. More than 80% had a high-grade (G3) endocrine component. Of the 152 patients followed up for a median of 20 months (interquartile range limits, 16.5-32), median overall survival was 12.3 months (95% credible interval [95%CrI], 11.3-13.7), with a 1.12 [95%CrI, 0.67-1.83] age-adjusted hazard ratio between metastatic and non-metastatic MANEC. Stage IV disease at diagnosis was more prognostically unfavorable in cases of colonic compared to anorectal origin.

CONCLUSION

MANEC is a clinically aggressive pathological entity. The results of this study provide new insights for the understanding of tumor location within the lower GI tract and its prognosis in terms of overall survival.

Diagnosis and Treatment of Primary Tumors of the Appendix: a Critical Review

INTRODUCTION

The aim of the current paper was to critically collect, select and summarize the evidence regarding diagnosis, treatment and follow up of primary tumors of the appendix.

METHODS

A literature review was performed by search and review of the scientific studies pertaining to the subject of our inquiry.

RESULTS

Recommendations regarding pimary tumors of the appendix were formulated on the basis of the collected evidence. CONCLUSION : Primary tumors of the appendix are rare and a high index of suspicion is required not to miss a potentially life threatening medical condition.

Mixed epithelial endocrine neoplasms of the colon and rectum – An evolution over time: A systematic review

BACKGROUND

Mixed tumors of the colon and rectum, composed of a combination of epithelial and endocrine elements of benign and malignant potential are rare neoplasms. These can occur anywhere in the gastrointestinal tract and are often diagnosed incidentally. Though they have been a well-documented entity in the pancreas, where the exocrine-endocrine mixed tumors have been known for a while, recognition and accurate diagnosis of these tumors in the colon and rectum, to date, remains a challenge. This is further compounded by the different terminologies that have been attributed to these lesions over the years adding to increased confusion and misclassification. Therefore, dedicated literature reviews of these lesions in the colon and rectum are inconsistent and are predominantly limited to case reports and case series of limited case numbers. Though, most of these tumors are high grade and of advanced stage, intermediate and low grade lesions of these mixed tumors are also increasingly been reported. There are no established independent consensus based guidelines for the therapeutic patient management of these unique lesions.

AIM

To provide a comprehensive targeted literature review of these complex mixed tumors in the colon and rectum that chronicles the evolution over time with summarization of historical perspectives of terminology and to further our understanding regarding their pathogenesis including genomic landscape, clinicoradiological features, pathology, treatment, prognosis, the current status of the management of the primary lesions, their recurrences and metastases.

METHODS

A comprehensive review of the published English literature was conducted using the search engines PubMed, MEDLINE and GOOGLE scholar. The following search terms [“mixed tumors colon” OR mixed endocrine/neuroendocrine tumor/neoplasm/lesion colon OR adenocarcinoma and endocrine/neuroendocrine tumor colon OR mixed adenocarcinoma and endocrine/neuroendocrine carcinoma colon OR Amphicrine tumors OR Collision tumors] were used. Eligibility criteria were defined and all potential relevant items, including full articles and/or abstracts were independently reviewed, assessed and agreed upon items were selected for in-depth analysis.

RESULTS

In total 237 full articles/abstracts documents were considered for eligibility of which 45 articles were illegible resulting in a total of 192 articles that were assessed for eligibility of which 139 have been selected for reference in this current review. This seminal manuscript is a one stop article that provides a detailed outlook on the evolution over time with summarization of historical perspectives, nomenclature, clinicoradiological features, pathology, treatment, prognosis and the current status of the management of both the primary lesions, their recurrences and metastases. Gaps in knowledge have also been identified and discussed. An important outcome of this manuscript is the justified proposal for a new, simple, clinically relevant, non-ambiguous terminology for these lesions to be referred to as mixed epithelial endocrine neoplasms (MEENs).

CONCLUSION

MEEN of the colon and rectum are poorly understood rare entities that encompass an extensive range of heterogeneous tumors with a wide variety of combinations leading to tumors of high, intermediate or low grade malignant potential. This proposed new revised terminology of MEEN will solve the biggest hurdle of confusion and misclassification that plagues these rare unique colorectal neoplasms thus facilitating the future design of multi institutional prospective randomized controlled clinical trials to develop and evaluate newer therapeutic strategies that are recommended for continued improved understanding and personal optimization of clinical management of these unique colorectal neoplasms.

Appendiceal Neuroendocrine Tumors: Does Colon Resection Improve Outcomes?

BACKGROUND

Appendiceal neuroendocrine tumors (A-NETs) are rare neoplasms of the GI tract. They are typically managed according to tumor size; however, the impact of surgical strategy on the short- and long-term outcomes is unknown.

METHODS

All patients who underwent resection of A-NET at 8 institutions from 2000 to 2016 were analyzed retrospectively. Patient clinicopathologic features and outcomes were stratified according to resection type.

RESULTS

Of 61 patients identified with A-NET, mean age of presentation was 44.7 ± 16.0 years and patients were predominantly Caucasian (77%) and female (56%). Mean tumor size was 1.2 ± 1.3 cm with a median of 0.8 cm. Thirty-one patients (51%) underwent appendectomy and 30 (49%) underwent colonic resection. The appendectomy group had more T1 tumors (87% vs 42%, p < 0.01) than the colon resection group. Of patients in the colon resection group, 27% had positive lymph nodes and 3% had M1 disease. R0 resections were achieved in 90% of appendectomy patients and 97% of colon resection patients. Complications occurred with a higher frequency in the colon resection group (30%) compared with those in the appendectomy group (6%, p = 0.02). The colon resection group also had a longer length of stay, higher average blood loss, and longer average OR time. Median RFS and OS were similar between groups.

CONCLUSION

A-NET RFS and OS are equivalent regardless of surgical strategy. Formal colon resection is associated with increased length of stay, OR time, higher blood loss, and more complications. Further study is warranted to identify patients that are likely to benefit from more aggressive surgery.

Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Versus Surgery Without HIPEC for Goblet-Cell Carcinoids and Mixed Adenoneuroendocrine Carcinomas: Propensity Score-Matched Analysis of Centers in the Netherlands and Belgium

BACKGROUND

The value of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with peritoneally metastasized goblet-cell carcinoids (GCCs) and mixed adenoneuroendocrine carcinomas (MANECs) is currently unclear. We compared outcomes of CRS-HIPEC to surgery alone for peritoneally metastasized GCCs and MANECs.

PATIENTS AND METHODS

Two cohorts were obtained from the Netherlands Cancer Registry (n = 569): patients with peritoneally metastasized GCCs and MANECs treated with CRS-HIPEC in Dutch and Belgian centers (n = 45), and patients treated with surgery alone. Primary outcome was overall survival (OS). Secondary outcomes were morbidity and hospital mortality. After propensity score matching, OS was compared in univariate and multivariate analyses. A systematic literature review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines from database inception to June 25, 2018.

RESULTS

After matching for sex, tumor stage, lymph node stage, and liver metastases, CRS-HIPEC was associated with improved median OS in the combined GCC and MANEC group and the separate GCC subgroup in univariate (GCC + MANEC: 39 vs. 12 months, P < .001; GCC: 39 vs. 12 months, P = .017) and multivariate analysis (GCC + MANEC: hazard ratio 4.27, 95% confidence interval 1.88-9.66, P = .001; GCC: hazard ratio 2.77, 95% confidence interval 1.06-7.26, P = .038). Acceptable grade III-IV morbidity (17.5%) and mortality (0) were seen after CRS-HIPEC. The literature review supported these findings.

CONCLUSION

CRS-HIPEC is associated with substantial survival benefit in patients with peritoneally metastasized GCCs and MANECs compared to surgery alone and is a safe treatment option. These data support centralized care of GCC and MANEC patients with peritoneal spread in expert centers offering CRS-HIPEC.

Survival Profile and Prognostic Factors for Appendiceal Mixed Neuroendocrine Non-neuroendocrine Neoplasms: A SEER Population-Based Study

Introduction

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare form of neuroendocrine neoplasms (NENs). The purpose of this study was to investigate the characteristics and survival profile of appendiceal MiNENs, with a view of providing robust clinical features of this rare disease.

Methods

Patients were selected from the Surveillance, Epidemiology, and End Results database (2004–2016). The prognosis of MiNEN (n = 315) was compared with other histological subtypes including neuroendocrine tumor (NETs) (n = 1734), neuroendocrine carcinoma (NECs) (n = 375), goblet cell carcinoid (GCC) (n = 968), signet ring cell carcinoma (n = 463), mucinous adenocarcinoma (MAC) (n = 2355), and non-mucinous adenocarcinoma (NMAC) (n = 1187) in the appendix. Age-adjusted incidence was calculated using Joinpoint regression. The Cox proportional hazards model and the Fine–Gray competing risk model were used to perform overall survival (OS) and cancer-specific mortality (CSM) analyses, respectively.

Results

The age-adjusted incidence of MiNENs increased from 0.01/100,000 person-years in 2004 to 0.07/100,000 person-years in 2016. The 3-, 5-, and 10-year OS rates for MiNENs were 69.5, 57.4, and 43.7%, respectively, and the corresponding CSM rates were 23.1, 36.4, and 45.1%, respectively. Multivariate analysis revealed that the prognosis of MiNENs was worse than that of NETs, NECs, GCC, and MAC but better than that of NMAC and signet ring cell carcinoma. Tumor extension was the only independent factor influencing the prognosis of MiNENs, but tumor size, grade, and surgical approaches were not. Moreover, when compared with local excision or appendectomy, extensive surgery such as hemicolectomy or colectomy did not prolong the survival of individuals with MiNENs.

Conclusion

MiNEN is a rare but aggressive tumor with a poor prognosis differing from NENs, GCC and adenocarcinomas. To improve the prognosis of the disease, early diagnosis and comprehensive evaluation are necessary.

Gastrointestinal mixed adenoneuroendocrine carcinoma: a population level analysis of epidemiological trends

Background

The rise in incidence and mortality of gastrointestinal mixed adenoneuroendocrine carcinoma (MANEC) has not been well focused. The aim of our study was to examine epidemiological trends in incidence and incidence-based (IB) mortality of gastrointestinal MANEC at a population level.

Methods

The incidence and IB mortality of gastrointestinal MANEC as well as data on affected patients from 2000 to 2016 were obtained from the Surveillance, Epidemiology, and End Results database. Trends in incidence and IB mortality were assessed using Joinpoint regression. The Kaplan–Meier method and log-rank test were used for survival analysis. Cox proportional hazards regression was used to identify independent predictors of mortality.

Results

581 patients diagnosed with gastrointestinal MANEC were enrolled. Gastrointestinal MANEC incidence was 0.23 cases per 1,000,000 individuals in 2000 and 1.16 cases per 1,000,000 individuals in 2016, with an annual percent change (APC) of 8.0% (95% CI 5.7–10.3%, P < 0.05). IB mortality also showed a sustained increase (APC 12.9%, 95% CI 9.0–16.8%, P < 0.05). In Cox regression analysis, age at diagnosis, tumor grade and stage, lymph node metastasis, surgery, and tumor size were independently associated with mortality. Median survival was 75 months (95% CI 60–128 months). Median survival of appendiceal MANEC was significantly longer than that of cecal MANEC (115 vs. 31 months; P < 0.001).

Conclusions

We found a sustained and rapid increase both in incidence and IB mortality of gastrointestinal MANEC, manifesting that there has been no significant improvement in patient outcomes, nor progress in prevention and treatment. Additional resources should be devoted to gastrointestinal MANEC research.

Mixed Neuroendocrine Non-Neuroendocrine Neoplasms: A Systematic Review of a Controversial and Underestimated Diagnosis

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) represent a rare diagnosis of the gastro-entero-pancreatic tract. Evidence from the current literature regarding their epidemiology, biology, and management is of variable quality and conflicting. Based on available data, the MiNEN has an aggressive biological behaviour, mostly driven by its (often high-grade) neuroendocrine component, and a dismal prognosis. In most cases, the non-neuroendocrine component is of adenocarcinoma histology. Due to limitations in diagnostic methods and poor awareness within the scientific community, the incidence of MiNENs may be underestimated. In the absence of data from clinical trials, MiNENs are commonly treated according to the standard of care for pure neuroendocrine carcinomas or adenocarcinomas from the same sites of origin, based on the assumption of a biological similarity to their pure counterparts. However, little is known about the molecular aberrations of MiNENs, and their pathogenesis remains controversial; molecular/genetic studies conducted so far point towards a common monoclonal origin of the two components. In addition, mutations in tumour-associated genes, including TP53, BRAF, and KRAS, and microsatellite instability have emerged as potential drivers of MiNENs. This systematic review (91 full manuscripts or abstracts in English language) summarises the current reported literature on clinical, pathological, survival, and molecular/genetic data on MiNENs.

Do neuroendocrine carcinomas and mixed neuroendocrine-non-neuroendocrine neoplasm of the gastrointestinal tract have the same prognosis? A SEER database analysis of 12,878 cases

BACKGROUND

Neuroendocrine carcinomas (NECs) and mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) in the gastrointestinal (GI) tract are both rare and malignant; however, it is unclear whether their prognosis is the same.

METHODS

In this cross-sectional study, a total of 12,878 patients with NEC or MiNEN in the GI tract were reviewed retrospectively by searching the Surveillance, Epidemiology, and End Results (SEER) program database. Next, we compared the characteristics and survival between patients with NEC or MiNEN and further analyzed the prognostic factors for the patients.

RESULTS

The data showed that patients with MiNEN had a worse prognosis as compared with patients with pure NEC in the small intestine (SI) and appendix, whereas there was no significant survival difference between NEC and MiNEN in the other parts of the GI system. On the whole, age ⩾55 years (p < 0.0001), male (p = 0.002), being diagnosed at TNM Stage II-IV (p < 0.0001) or not receiving surgical treatment (p < 0.0001) were the independent negative prognostic factors for NEC patients, whereas age ⩾55 years (p = 0.003), being diagnosed at TNM Stage III-IV (p < 0.001) or not receiving surgical treatment (p < 0.001) were identified as the independent negative prognostic factors for the MiNEN patients. Furthermore, when NECs or MiNENs were classified based on the primary tumor site, the results showed that the prognostic factors for NEC and MiNEN varied between the tumor sites.

CONCLUSION

The prognostic differences between NECs and MiNENs in the GI tract are heterogeneous and site-related. Patients with appendiceal or SI MiNEN have a poorer prognosis than patients with pure appendiceal or SI NEC. Therefore, we should pay more attention to patients with MiNEN in the SI and appendix and monitor them more closely.

Amphicrine carcinoma of the stomach and intestine: a clinicopathologic and pan-cancer transcriptome analysis of a distinct entity

Background and aim

Amphicrine carcinoma, in which endocrine and epithelial cell constituents are present within the same cell, is very rare. This study characterized the clinicopathologic and survival analysis of this tumor, further compared the genetic diversities among amphicrine carcinoma and other tumors.

Materials and methods

The clinicopathologic characteristics and survival outcomes of amphicrine carcinoma in this study were analyzed. The pan-cancer transcriptome assay was utilized to compare the genetic expression profile of this entity with that of conventional adenocarcinoma or neuroendocrine tumors.

Results

Ten cases (all in male patients) were identified in the stomach or intestine, with a median patient age of 62 years. There were characteristic patterns in the tumors: tubular, fusion or single-file growth of goblet- or signet ring-like cells. Four tumors were classified as low-grade and 6 as high-grade according to the histologic architecture. All cases were positive for neuroendocrine markers (synaptophysin and chromogranin A) and showed intracellular mucin in the amphicrine components. Four cases exhibited mRNA expression patterns showing transcriptional homogeneity with conventional adenocarcinomas and genetic diversity from neuroendocrine tumors. During the follow-up period, 3 patients died of disease, all of whom had high-grade tumors. Patients with high-grade amphicrine carcinoma had worse outcomes than those with low-grade tumors.

Conclusions

This study confirms the morphological, immunostaining and transcriptome alterations in amphicrine carcinoma distinct from those in conventional adenocarcinomas and neuroendocrine tumors, but additional studies are warranted to determine the biological behavior and therapeutic response.

Impact of neuroendocrine morphology on cancer outcomes and stage at diagnosis: a UK nationwide cohort study 2013-2015

BACKGROUND

The diagnosis of neuroendocrine neoplasms (NENs) is often delayed. This first UK population-based epidemiological study of NENs compares outcomes with non-NENs to identify any inequalities.

METHODS

Age-standardised incidence rate (ASR), 1-year overall survival, hazard ratios and standardised mortality rates (SMRs) were calculated for all malignant NENs diagnosed 2013-2015 from UK national Public Health records. Comparison with non-NENs assessed 1-year overall survival (1YS) and association between diagnosis at stage IV and morphology.

RESULTS

A total of 15,222 NENs were identified, with an ASR (2013-2015 combined) of 8.6 per 100,000 (95% CI 8.5-8.7); 4.6 per 100 000 (95% CI, 4.5-4.7) for gastro-entero-pancreatic (GEP) NENs. The 1YS was 75% (95% CI, 73.9-75.4) varying significantly by sex. Site and morphology were prognostic. NENs (predominantly small cell carcinomas) in the oesophagus, bladder, prostate, and female reproductive organs had a poorer outcome and were three times more likely to be diagnosed at stage IV than non-NENs.

CONCLUSION

Advanced stage at diagnosis with significantly poorer outcomes of some NENs compared with non-NENs at the same anatomical site, highlight the need for improved access to specialist services and targeted service improvement.

Management of Gastrointestinal Neuroendocrine Tumors

Neuroendocrine neoplasms (NENs) are derived from neuroendocrine cell system and can have benign or malignant characteristics. They are rare tumors, but have been increasing in incidence over the past 40 years. Patients with NENs may develop symptoms due to primary tumor invasion, metastasis, or from secretion of hormonally active tumor substances. Multiple imaging modalities are used for diagnosis and staging, including specialty scans such as ¹¹¹In pentetreotide (Octreoscan) and ⁶⁸Gallium-DOTATATE, along with endoscopy, endoscopic ultrasound, and biochemical marker testing. Treatment involves both surgical approach, for both primary and metastatic lesions, as well as medical management for symptom management and disease progression. This article will review the current clinical knowledge regarding the diagnosis, treatment, and prognosis of these fascinating neoplasms and the associated hormonal syndromes.

Retrospective study on mixed neuroendocrine non-neuroendocrine neoplasms from five European centres

BACKGROUND

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare diagnosis, mainly encountered in the gastro-entero-pancreatic tract. There is limited knowledge of its epidemiology, prognosis and biology, and the best management for affected patients is still to be defined.

AIM

To investigate clinical-pathological characteristics, treatment modalities and survival outcomes of a retrospective cohort of patients with a diagnosis of MiNEN.

METHODS

Consecutive patients with a histologically proven diagnosis of MiNEN were identified at 5 European centres. Patient data were retrospectively collected from medical records. Pathological samples were reviewed to ascertain compliance with the 2017 World Health Organisation definition of MiNEN. Tumour responses to systemic treatment were assessed according to the Response Evaluation Criteria in Solid Tumours 1.1. Kaplan-Meier analysis was applied to estimate survival outcomes. Associations between clinical-pathological characteristics and survival outcomes were explored using Log-rank test for equality of survivors functions (univariate) and Cox-regression analysis (multivariable).

RESULTS

Sixty-nine consecutive patients identified; Median age at diagnosis: 64 years. Males: 63.8%. Localised disease (curable): 53.6%. Commonest sites of origin: colon-rectum (43.5%) and oesophagus/oesophagogastric junction (15.9%). The neuroendocrine component was; predominant in 58.6%, poorly differentiated in 86.3%, and large cell in 81.25%, of cases analysed. Most distant metastases analysed (73.4%) were occupied only by a poorly differentiated neuroendocrine component. Ninety-four percent of patients with localised disease underwent curative surgery; 53% also received perioperative treatment, most often in line with protocols for adenocarcinomas from the same sites of origin. Chemotherapy was offered to most patients (68.1%) with advanced disease, and followed protocols for pure neuroendocrine carcinomas or adenocarcinomas in equal proportion. In localised cases, median recurrence free survival (RFS); 14.0 months (95%CI: 9.2-24.4), and median overall survival (OS): 28.6 months (95%CI: 18.3-41.1). On univariate analysis, receipt of perioperative treatment (vs surgery alone) did not improve RFS (P = 0.375), or OS (P = 0.240). In advanced cases, median progression free survival (PFS); 5.6 months (95%CI: 4.4-7.4), and median OS; 9.0 months (95%CI: 5.2-13.4). On univariate analysis, receipt of palliative active treatment (vs best supportive care) prolonged PFS and OS (both, P < 0.001).

CONCLUSION

MiNEN is most commonly driven by a poorly differentiated neuroendocrine component, and has poor prognosis. Advances in its biological understanding are needed to identify effective treatments and improve patient outcomes.

Typical carcinoids, goblet cell carcinoids, mixed adenoneuroendocrine carcinomas, neuroendocrine carcinomas and adenocarcinomas of the appendix: a comparative analysis of survival profile and predictors

Background

Goblet cell carcinoids (GCC) and other atypical neuroendocrine tumors (NET) of the appendix as well as appendiceal adenocarcinoma are usually managed with the same algorithm as colon cancers. This study investigates clinicopathological features that are predictive of survival outcomes for appendiceal NET and adenocarcinoma. Survival profiles for the histologic subtypes of appendiceal NET and adenocarcinoma were compared.

Methods

A retrospective review of appendiceal NET and adenocarcinoma for patients who are 18 years and above in the SEER database from 2010 to 2014.

Results

Females outnumbered males in a 1.3 to 1 ratio in the NET subgroup and 1.1 to 1 ratio in the adenocarcinoma group. The mean age at diagnosis for all NET was 50.3±17 years while that of adenocarcinomas was 60.8±14.1 years. Within the NET subgroups, the mean ages for typical carcinoids (TC), GCC, NEC and MANEC were 42.9±17.3, 56.7±13.7, 45.6±17.4 and 59.7±12.8 years, respectively. Overall survival for adenocarcinoma was 86.3%, 73.5%, 65.7%, and 57.6% for 1-, 2-, 3- and 4-year OS, respectively. For NET, TC showed better survival profile with 1- and 4-year overall survival of 97.4% and 95.7%, respectively while MANEC had the worst survival outcome with 1- and 4-year OS of 88.6% and 62.2%, respectively. GCC had a better 1-year OS compared to NEC (95.5% versus 92.9%) but showed slightly worse 4-year OS (82% versus 84.8%). Age at diagnosis (HR 1.03), African-American race (HR 1.47) and stage IV disease (HR 9.58) were independent predictors of survival for appendiceal adenocarcinoma. For NET, advanced age at diagnosis, advanced disease stage and the African-American race were identified as negative independent predictors of survival.

Conclusions

While prior studies have suggested that atypical NET (GCC, NEC and MANEC) are more likely to present at more advanced stages, this study showed that most cases of GCC, MANEC and NEC were diagnosed at stages I and II. Appendiceal adenocarcinoma, on the other hand, presented mostly at stage IV. With respect to OS, atypical histologic subtypes of NET have worse outcome compared to TC. Although better OS was noted for GCC, NEC and MANEC when compared to adenocarcinoma, this benefit was lost in stage IV disease where adenocarcinoma recorded better 1- and 4-year OS. Prospective and randomized studies which provide granular details of treatment are needed to better define treatment algorithm for appendiceal NET.

Mixed Adeno-Neuroendocrine Carcinoma; Case Series of Ten Patients with Review of the Literature

Aims:

Mixed adeno-neuroendocrine carcinoma is a rare entity, diagnosed with immunohistochemical studies. Literature mainly includes case reports and series which are very few. In our study, we aimed to report a case series from a tertiary hospital with demographics of the patients, detailed tumor and clinical findings and follow-up plus survival conditions.

Methods:

Pathology database was explored for patients with the pathological diagnosis of ‘mixed adeno-neuroendocrine carcinoma’ and patients were identified retrospectively and evaluated in means of demographics, histopathological examination, tumor properties.

Results:

Ten patients had been diagnosed with mixed adeno-neuroendocrine carcinoma in our center, diagnosed at a mean age of 64.7. Stomach was found to be the most common localization. Five patients (50%) were diagnosed as grade 3. Following surgery, median follow-up was 15 months with a median survival time of 20.6 months.

Conclusion:

This case series may contribute to the literature on the pathological and clinical aspects of the mixed adenoneuroendocrine carcinoma of the gastrointestinal system.

Mixed adenoneuroendocrine carcinoma of the tongue arising within a congenital enteric cyst

BACKGROUND

Primary intestinal-type adenocarcinoma of the tongue is rare. This represents the first reported case of a primary mixed adenoneuroendocrine carcinoma (MANEC) of the tongue arising within a congenital enteric cyst.

METHODS

A 52-year-old man presented with a midline tongue mass that was connected to the mucosal surface with an epithelial-lined sinus tract. Morphological examination and immunohistochemical profiling of the neoplasm were performed.

RESULTS

Histopathological evaluation showed a primary MANEC arising within a preexisting congenital enteric cyst, comprising both adenocarcinoma and neuroendocrine components. The adenocarcinoma had a colonic-type morphology and coexpressed CK7, CK20, and CDX2. Imaging and colonoscopy excluded a distant primary colorectal neoplasm.

CONCLUSION

The association of primary MANEC of the tongue with a gastrointestinal heterotopic cyst supports an origin from entrapped endodermal elements as opposed to salivary duct origin. This case raises the awareness of a rare yet prognostically important complication of a gastrointestinal heterotopic cyst.

Mixed Adenoneuroendocrine Carcinoma of the Esophagus: A Case Report and Review of the Literature

The most frequent presentation of esophageal cancer is adenocarcinoma and squamous cell carcinoma. In recent years, the latter has decreased its incidence increasing the adenocarcinoma. Currently, another type of tumor with a much lower incidence has been described, which has a neuroendocrine component along with another exocrine glandular component and has been classified since 2010 as mixed adenoneuroendocrine carcinoma (MANEC). We present the case of a 68-year-old male with a history of dyspepsia and epigastric pain who after performing a gastroscopy, was diagnosed with a malignant neoplasm of the esophagus. The patient underwent a total esophagectomy with reconstruction by tubular gastroplasty with cervical anastomosis. The final result of the piece after immunohistochemistry revealed that the tumor was composed of one component of adenocarcinoma in 60% together with another component compatible with neuroendocrine in 40%. With these findings and according to the World Health Organization classification of 2010 was diagnosed as esophageal MANEC. MANECs are rare tumors, described in other locations of the digestive tract, the esophagus being an infrequent location. Its preoperative diagnosis is difficult, and it is not until the final analysis of the complete piece by means of specific immunohistochemical techniques when its diagnosis can be established. Its treatment is fundamentally surgical, whereas the adjuvant therapeutic schemes with chemotherapy are not well defined at present because of their low incidence.

Mixed adenoneuroendocrine carcinoma: A review of pathologic characteristics

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare pathologic entity defined as a tumor exhibiting both adenocarcinoma and neuroendocrine carcinoma components. Though uncommon, these tumors show aggressive behavior and generally portend a poor prognosis. This study seeks to further define clinicopathological characteristics of MANEC to aid in accurate diagnosis and properly direct clinical management. Thirty-four confirmed MANECs were identified in our 25-year retrospective review of cases arising in the gastrointestinal tract. Various gross and microscopic variables were compared to overall survival. Tumors diagnosed at advanced stage (pT4), had a prominent mucinous component and lacked goblet cell clusters, which were all significantly associated with worse overall survival. This study supports previous findings and further elucidates clinicopathologic characteristics of MANEC.

Correlation of metastasis characteristics with prognosis in gastric mixed adenoneuroendocrine carcinoma: Two case reports

RATIONALE

This article is aimed to retrospect the clinicopathological data of 2 cases of gastric MANENCs. MANEC is a rare biphasic tumor type that is coexistence of dual neuroendocrine and adenocarcinoma differentiation with each composing exceeding 30% volume. Gastric MANEC have just been reported anecdotally in the literature due to their rarity and heterogeneity. According to our study, these neoplasms have 3 different metastasis patterns: only adenocarcinomatous or neuroendocrine carcinoma and both of the 2 components. We first focus on the correlation of metastasis characteristics with prognosis in gastric MANEC, which may be potential implications for the choice of chemotherapy.

PATIENT CONCERNS

The 2 cases of patient shared several symptoms: epigastric discomfort, weight loss, hematemesis, or melena.

DIAGNOSIS

The 2 patients were diagnosis as MANEC based on the identification of histopathological analysis. In case 1, the poor differentiated adenocarcinoma accounted for 30%, the neuroendocrine part account for 70% and both of the 2 components metastasized to the lymph nodes, whereas in case 2, poorly differentiated adenocarcinoma accounted for 70%, the neuroendocrine part for 30% and only the glandular component invaded regional lymph nodes.

INTERVENTIONS

The first patient underwent laparoscopic radical gastrectomy and underwent adjuvant chemotherapy, combination of cisplatin, and etoposide successfully. The second patient received radical gastronomy, and did not receive any chemotherapy due to general weakness.

OUTCOMES

The first patient is alive with no evidence of recurrence, and the second patient died 6 months after the operation.

LESSONS

The assessment of metastatic sites should be a routine pathological practice, which is crucial for clinical decision-making and the selection of management.

Regional lymph node involvement and outcomes in appendiceal neuroendocrine tumors: a SEER database analysis

Background

Appendiceal neuroendocrine neoplasms are most often diagnosed incidentally during appendectomy. The need for subsequent right hemicolectomy (RHC) is determined based on the risk of regional lymph node (LN) involvement. Tumor size has historically been used as an indicator of this risk, but controversy remains regarding its cut off. Furthermore, the impact of RHC on survival is unclear.

Methods

We used the SEER database to identify patients diagnosed with appendiceal neuroendocrine tumors.

Results

Of 1731 patients, 38.0% had well-differentiated neuroendocrine tumors (WDNETs), 60.8% had mixed histology tumors (MHTs), and 1.2% had poorly differentiated neuroendocrine carcinomas (PDNECs). In patients with WDNETs and MHTs who had adequate lymphadenectomy, higher rates of LN involvement were noted for tumors size 11-20 mm than ≤10 mm (56.8% vs. 11.6%, p <0.001; 32.9% vs. 10.4%, p=0.004, respectively). The type of surgery did not affect OS in cases with MHTs with LN involvement (HR 1.00; 95% CI, 0.53-1.89; p =0.99). Patients with regionally advanced WDNET showed excellent survival and only 3 patients (out of 118) died from cancer within 10 years.

Conclusions

10 mm appears to be a more appropriate cutoff than 20 mm for predicting LN metastasis in appendiceal NETs. Cases with WDNETs and nodal involvement demonstrate overall excellent prognosis irrespective of type of surgery (i.e. RHC may not improve outcome). In MHTs with LN metastases, survival is markedly worse in spite of RHC. The role of adjuvant therapy should be evaluated in this subset.

Mutation landscape and intra-tumor heterogeneity of two MANECs of the esophagus revealed by multi-region sequencing

Mixed adenoneuroendocrine carcinoma (MANEC) in the esophagus is an infrequent but highly malignant cancer with few known genomic alterations. We conducted whole-exome sequencing and whole-genome SNP genotyping for 4-6 tumor subregions and 5-6 adjacent normal tissue sites and 1-3 lymph node metastases in two esophageal MANECs to detect somatic mutations and copy number alterations, and to explore their spatial heterogeneity and underlying clonal structure. TP53 mutation, RB1 deletion or LOH, and PIK3CA, PTEN, KRAS, SOX2, DVL3, TP63 amplification appeared in all regions in both tumors. Mutations falling in known cancer genes tended to show higher variant allele frequencies than those not falling in these genes in at least one of the cases. Phylogenetic analyses of the samples and underlying subclones suggested extensive migration across different tumor regions and from some regions to the lymph nodes. Lymph node metastases appeared to have been seeded by both early founder cells as well as subsequent, locally emerging daughter clones. A phenotypically normal tissue site carried most of the mutations found in neighboring tumor samples, implying field cancerization. Understanding such complex genetic heterogeneity within each patient will be important for guiding clinical decisions.

Appendiceal goblet cell carcinoid: common errors in staging and clinical interpretation with a proposal for an improved terminology

Goblet cell carcinoid (GCC) is staged and treated as adenocarcinoma (AC) and not as neuroendocrine tumor (NET) or neuroendocrine carcinoma. The term carcinoid may lead to incorrect interpretation as NET. The aim of the study was to explore pitfalls in staging and clinical interpretation of GCC and mixed GCC-AC, and propose strategies to avoid common errors. Diagnostic terminology, staging, and clinical interpretation were evaluated in 58 cases (27 GCCs, 31 mixed GCC-ACs). Opinions were collected from 23 pathologists using a survey. Clinical notes were reviewed to assess the interpretation of pathology diagnoses by oncologists. NET staging was incorrectly used for 25% of GCCs and 5% of mixed GCC-ACs. In the survey, 43% of pathologists incorrectly indicated that NET staging is applicable to GCCs, and 43% incorrectly responded that Ki-67 proliferation index is necessary for GCC grading. Two cases each of GCC and mixed GCC-AC were incorrectly interpreted as neuroendocrine neoplasms by oncologists, and platinum-based therapy was considered for 2 GCC-AC cases because of the mistaken impression of neuroendocrine carcinoma created by use of the World Health Organization 2010 term mixed adenoneuroendocrine carcinoma. The term carcinoid in GCC and use of mixed adenoneuroendocrine carcinoma for mixed GCC-AC lead to errors in staging and treatment. We propose that goblet cell carcinoid should be changed to goblet cell carcinoma, whereas GCC with AC should be referred to as mixed GCC-AC with a comment about the proportion of each component and the histologic subtype of AC. This terminology will facilitate appropriate staging and clinical management, and avoid errors in interpretation.

Colorectal mixed adenoneuroendocrine carcinomas and neuroendocrine carcinomas are genetically closely related to colorectal adenocarcinomas

Colorectal mixed adenoneuroendocrine carcinomas are rare and clinically aggressive neoplasms with considerable morphological heterogeneity. Data on their genomic characteristics and molecular associations to either conventional colorectal adenocarcinomas or poorly differentiated neuroendocrine neoplasms is still scarce, hampering optimized patient treatment and care. Tissue from 19 colorectal mixed adenoneuroendocrine carcinomas and eight colorectal poorly differentiated neuroendocrine neoplasms (neuroendocrine carcinomas) was microdissected and subjected to next-generation sequencing using a colorectal adenocarcinoma-specific panel comprising 196 amplicons covering 32 genes linked to colorectal adenocarcinoma, and poorly differentiated neuroendocrine neoplasm tumorigenesis. Mixed adenoneuroendocrine carcinomas were also examined for microsatellite instability and MLH-1 promoter methylation status. In three mixed adenoneuroendocrine carcinomas, exocrine and endocrine components were analyzed separately. Genetic testing of colorectal mixed adenoneuroendocrine carcinomas identified 43 somatic mutations clustering in 13/32 genes. Sixteen (84%) tumors harbored at least one somatic mutation, two tumors (11%) displayed high microsatellite instability. Compared with colorectal adenocarcinomas, mixed adenoneuroendocrine carcinomas were more frequently BRAF (37%; P=0.006), and less frequently KRAS (21%; P=0.043) and APC (16%; P=0.001) mutated. Point mutations in neuroendocrine neoplasm-related genes like RB1 or RET were not detected, but one tumor harbored a heterozygous RB1 deletion. Separately analyzed adenocarcinoma and neuroendocrine carcinoma components revealed a shared mutational trunk of driver genes involved in colorectal adenocarcinoma carcinogenesis. Colorectal neuroendocrine carcinomas were similar in their mutation profile to colorectal adenocarcinomas, but compared with mixed adenoneuroendocrine carcinomas, had a higher rate of APC mutations (P=0.027). Our data indicate that colorectal mixed adenoneuroendocrine carcinomas and neuroendocrine carcinomas are genetically closely related to colorectal adenocarcinomas, suggesting that the cells giving rise to these tumors primarily have an intestinal coinage. The identification of BRAF mutations and the frequently present KRAS wild-type status principally render some mixed adenoneuroendocrine carcinomas eligible to targeted treatment strategies used for colorectal adenocarcinomas.

Neuroendocrine, goblet cell and mixed adeno-neuroendocrine tumours of the appendix: updates, clinical applications and the future

Appendiceal neuroendocrine neoplasms are rare, clinically challenging tumours that are typically incidentally diagnosed, have a poorly understood biology and have controversy surrounding their management. Most are adequately treated with appendectomy, and although distant metastases are rare, the threat of disease dissemination remains and current guidelines possess poor accuracy in terms of selecting patients requiring more extensive surgery, i.e. oncological right-hemicolectomy. Areas covered: In this article, we discuss the presentation and diagnostic work-up of patients with appendiceal neuroendocrine neoplasms, and also examine the evidence base for existing management strategies. We highlight controversies within the management of these tumours, and anticipate avenues for further progress. Although no longer classified as neuroendocrine neoplasms, we also discuss two related forms of tumours with neuroendocrine features - goblet cell cancers and mixed adeno-neuroendocrine carcinomas. Expert commentary: Existing guidelines for the treatment of appendiceal neuroendocrine neoplasms are derived from a limited evidence base and are unable to accurately predict which patients require extensive attempts at surgical disease control. Future advances in the field of improved patient selection for more extensive surgery may be possible with multi-factorial tumour assessment integrating morphological and molecular analyses.

Appendiceal Mixed Adeno-Neuroendocrine Carcinoma: A Population-Based Study of the Surveillance, Epidemiology, and End Results Registry

INTRODUCTION

Mixed adeno-neuroendocrine carcinoma (MANEC) is a rare pathological diagnosis recently defined by the World Health Organization (WHO) in 2010. Prior to the definition by the WHO, tumors with both adenocarcinoma and neuroendocrine components were given multiple pathological designations making it difficult to characterize the disease. The aim of our study is to better characterize MANEC to better understand its natural history to influence patient care and positively impact outcomes.

MATERIALS AND METHODS

The surveillance, epidemiology, and end results program database was queried for all patients aged 18 years or older between 1973 and 2012 who had the diagnosis composite carcinoid (n = 249) of the appendix. Composite carcinoid tumors refer to tumors that have both adenocarcinoma and carcinoid tumor components present, consistent with that pathological diagnosis MANEC. For comparison, the database was also queried for carcinoid tumor of the appendix (n = 950), signet ring cell carcinoma of the appendix (n = 579), and goblet cell carcinoid (GCC) tumors of the appendix (n = 944). The data were retrospectively reviewed, and clinicopathological characteristics, treatment regimens, and survival data were obtained.

RESULTS

The median age of diagnosis of MANEC tumors was 58 years of age. Eighty percent of patients were White, and 49% were female. Fifty-four percent of patients underwent hemicolectomy and 31% had partial/subtotal colectomy as their surgical management. Median overall survival for MANEC was 6.5 years (95% CI 4.5-9.7), which was statistically significantly shorter (p < 0.0001) in comparison to 13.8 years (95% CI 12.1-16.5) for GCC, 2.1 years (95% CI 1.8-2.3) for signet ring cell carcinoma, and 39.4 years (95% CI 37.1-NA) for carcinoid tumors.

DISCUSSION

MANEC is a more aggressive clinical entity than both GCC of the appendix and carcinoid tumors of the appendix. Based on these findings, patients with MANEC tumors should undergo aggressive multidisciplinary cancer management.