Mixed adenoneuroendocrine carcinoma of gastrointestinal tract: Report of two cases

Mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) of the rectum

A 75-year-old man presented to our hospital complaining of abdominal distention. He underwent lower gastrointestinal endoscopic examination, which indicated a raised tumor of 20 mm in diameter in the sigmoid colon transition region of the rectum. Endoscopic mucosal resection was performed with the aims of treatment and diagnosis. Histopathological examination revealed a moderately differentiated adenocarcinoma with neuroendocrine carcinoma, which was classified as a mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN). The tumor had highly invaded the submucosa and positive vertical margins. Computed tomography showed no obvious lymph node metastasis or distant metastasis, so the patient underwent high-level anterior resection of the remaining lesion. The final diagnosis was MiNEN, pT3(SS), INFb, Ly1c, V0, Pn1a, pPM0, pDM0, pRM0, pN1a, and pStage IIIb (TNM Classification of Malignant Tumors, 8th Edition). The patient is recurrence free at 3 years without postoperative adjuvant therapy. We report this case with a review of the literature.

Mixed neuroendocrine-non-neuroendocrine neoplasm of the colon treated with laparoscopic resection and adjuvant chemotherapy: a case report

Mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) of the colon is rare with a poor prognosis. Since the first description of a mixed neoplasm 100 years ago, the nomenclature has evolved, most recently with the 2022 World Health Organization (WHO) classification system. We describe our experience of a case of locoregionally advanced MiNEN of the descending colon treated with curative laparoscopic resection and adjuvant chemotherapy. The patient is a 72 year old woman who presented with haematochezia. Initial clinical diagnosis was poorly differentiated adenocarcinoma of the descending colon, cT2N0M0, cStage I. Laparoscopic partial colectomy of the descending colon with D3 lymph node dissection and intracorporeal overlap anastomosis was performed. The pathological diagnosis however, returned mixed adenocarcinoma-neuroendocrine carcinoma (MANEC) of the descending colon, pT4aN1bM0, pStage IIIB, a subgroup of MiNEN: 70% was neuroendocrine carcinoma (NEC), whilst poorly differentiated mucinous carcinoma constituted 30% of the tumour. She completed 4 courses of irinotecan plus cisplatin (IP) adjuvant chemotherapy and is currently recurrence-free at postoperative year 2. The clinical course of MiNEN depends on the biology of the two components, both of which must be pathologically characterised. Even quantitatively discrete components should be carefully subtyped as their prognostic relevance is undetermined.

Metastasis of Mixed Adenoneuroendocrine Carcinoma of the Uterine Cervix to Thyroid Gland

The thyroid metastasis from cervical cancer is extremely rare compared to other organs. It is sometimes difficult to distinguish primary tumors from metastases, as most metastatic thyroid nodules are asymptomatic. In this case, a 54-year-old woman had undergone radical hysterectomy due to cervical tumor of stage IB1 mixed adenoneuroendocrine carcinoma (MANEC) 5 years ago. After 3 years, ultrasound examination revealed a suspicious malignant nodule in the left lobe of thyroid gland at regular postoperative follow-up. This patient had no obvious clinical symptoms. The ultrasonography (US)-guided core needle biopsy (CNB) of the thyroid nodule was performed on the patient. The immunohistochemistry analyses revealed that it was poorly differentiated small-cell neuroendocrine carcinoma (SCNEC). Subsequently, the patient underwent left hemithyroidectomy plus isthmusectomy. The postoperative pathology and immunohistochemistry, combining with clinical history, confirmed that the thyroid nodule was a metastasis from cervical MANEC. Conventional chemotherapy and regular follow-up were carried out after the operation. The patient was readmitted 1 year later for pancreatic metastatic lesions and died 1 month after surgery. Early detection of metastatic cancer is potentially helpful, and when necessary, ultrasound-guided puncture biopsy can be utilized to further diagnose metastatic thyroid cancer.

Oligometastatic Mixed Neuroendocrine Adenocarcinoma of the Esophago-Gastric Junction: A Case of Successful Multidisciplinary Management, the Lessons Learnt and Review of the Literature

Background: Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) of the esophago-gastric junction (EGJ) are rare aggressive malignant neoplasms, with, currently, limited evidence regarding the appropriate therapeutic approach. Methods: Herein, we report multimodal treatment management of a patient with oligometastatic MiNEN of EGJ (Siewert III), discuss the lessons learnt, and provide a review of the literature. Results: A 69-year-old female was diagnosed with a locally advanced EGJ tumor and three liver metastases (cT4, cN+, M1). Although the initial histology from biopsy revealed adenocarcinoma, the histopathology of a lymph node biopsy from staging laparoscopy revealed infiltration of neuroendocrine carcinoma cells. Thus, the diagnosis of a mixed neuroendocrine adenocarcinoma was set, and systemic chemotherapy with etoposide and cisplatin was initiated. A major clinical response led to conversion surgical resection of the primary tumor and metastases, followed by adjuvant therapy with immunotherapy. The patient is free of disease at the 3-year follow-up. A review of the literature on similar cases of EGJ or gastric MiNENs revealed a limited number of cases. Out of the 39 patients, 20 of them (51.3%) suffered from advanced-stage disease. The MiNEN diagnosis typically occurred after surgical resection. Systemic chemotherapy against the neuroendocrine component demonstrated significant response rates, while in cases in which conversion surgery was offered, prolongation of survival was demonstrated. Conclusions: Our case and the existing literature on MiNENs of EGJ underline the need for a personalized treatment approach following thorough interpretation of comprehensive pretherapeutic staging. Conversion radical surgery with curative intent could be considered in cases of major or complete clinical response to induction chemotherapy with potentially favorable outcomes.

Diagnostic Approaches to Neuroendocrine Neoplasms of Unknown Primary Site

ABSTRACT

Neuroendocrine tumors (NETs) are relatively uncommon heterogeneous neoplasms arising from endocrine and neuronal origin cells showing highly variable clinical behavior. By the time these tumors are discovered, up to 14% of patients with histologically proven NETs have metastasis, with the liver as the most frequently affected organ. Sometimes, no known primary site can be identified via routine imaging. Neuroendocrine tumors of unknown origin carry a poorer prognosis (compared with metastatic NETs with a known primary site) because of a lack of tailored surgical intervention and appropriate medical therapy (eg, chemotherapy or targeted therapy). A multimethod approach is frequently used in the trial to accurately determine the primary site for NETs of unknown primary sites and may include clinical, laboratory, radiological, histopathological, and surgical data. New molecular techniques using the genomic approach to identify the molecular signature have shown promising results. Various imaging modalities include ultrasound, computed tomography (CT), dual-energy CT, magnetic resonance imaging, and functional and hybrid imaging (positron emission tomography/CT, positron emission tomography/magnetic resonance imaging); somatostatin receptor imaging with new tracers is frequently used in an attempt for localization of the primary site.

Adenocarcinoma admixed with neuroendocrine carcinoma of the cervix: A case report and review of literature

A 40-year-old Ethiopian woman presented with a six-month history of non-foul-smelling whitish vaginal discharge. She also reported a one-year history of postcoital bleeding. A pelvic examination revealed a nodular, hard, and fragile cervical mass. In addition, there were nontender, firm nodules in the epigastric, periumbilical, gluteal areas, and thyroid gland. Investigations, including abdominopelvic ultrasound, magnetic resonance imaging, fine-needle aspiration cytology, and immunohistochemistry, confirmed mixed neuroendocrine carcinoma of the cervix with metastasis to the abdominal wall, gluteal area, lumbar vertebrae, and thyroid gland. The patient was started on palliative chemotherapy. Metastatic adenocarcinoma admixed with neuroendocrine carcinoma of the cervix presents a formidable disease phenotype, characterized by complex diagnostic and therapeutic obstacles. Multidisciplinary cooperation among oncologists, radiologists, pathologists, and surgeons is required to refine treatment approaches and improve patient prognoses for this uncommon and intricate malignancy.

MANEC TUMOR OF RECTUM. A RARE CASE SERIES OF 3 PATIENTS AND A LITERATURE REVIEW

The term Mixed Adeno-Neuro-Endocrine Carcinoma (MANEC) was introduced in 2010 by the WHO Classification of Tumors of the Digestive System. It refers to a neoplasm with dual epithelial and neuroendocrine differentiation, each component representing at least 30% of the tumor. It is an uncommon tumor accounting for < 3% of all colon and rectum malignancies. We report three cases of this extremely rare MANEC of the rectum. All three cases presented with hematochezia, variable constipation, and abdominal pain. They were diagnosed and staged appropriately with colonoscopy, biopsy with immunohistochemistry, and imaging. They underwent an anterior resection with circular stapled anastomoses. Because of the low incidence of this histotype, we reviewed the clinical presentation, diagnostic characteristics, and treatment of MANEC of the colon and rectum.

A puzzling case report of well-differentiated neuroendocrine tumor mixed with gastric adenocarcinoma of the fundic gland type associated with autoimmune gastritis

Gastric adenocarcinoma of the fundic gland type (GA-FG) is a rare gastric neoplasm. We present a unique case of multiple GA-FG that coexisted with the well-differentiated neuroendocrine tumors in a patient with autoimmune gastritis. To our knowledge, this is the first documented instance of such a co-occurrence and the molecular mechanism of their origin has been reviewed systematically. A 47-year-old male presented to our hospital with abdominal distension for over 10 years. Gastroscopy revealed multiple gastric eminence lesions (0.2-1.5 cm). After endoscopic mucosal resection, the pathological morphology showed mixed tumor components infiltrating into the submucosa with puzzling similarity. One with uniform-sized tumor cells arranged in nests or tubes and the other a well-differentiated tubular adenocarcinoma with irregular branching and visible gland fusion. Immunohistochemistry findings revealed the first component expressed typical markers of neuroendocrine tumor, whereas the second component expressed pepsinogen and mucin-6, indicating the presence of oxyntic gland adenocarcinoma. Due to the tumors' proximity to the surgical margins, the patient underwent laparoscopic subtotal gastrectomy three months after the diagnosis without any tumor residue and showed no recurrence or metastasis occurred in the following regular checkups.

Deficient Mismatch Repair Proteins in Gastric Mixed Neuroendocrine Non-Neuroendocrine Neoplasm: A Rare Case Report

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare type of gastric carcinoma with controversial diagnosis and treatment. Recent data implies that deficiency mismatch repair proteins inducing microsatellite instability are considered one of the potential drivers of this disease. Hence, we report a stomach MiNEN with MMR protein loss. An admitted 60-year-old woman complained of epigastric pain. The pathological analysis of the gastro-endoscopic biopsy specimen revealed gastric adenocarcinoma. The radiological staging was cT3N1M0; therefore, she received D2 distal gastrectomy. Suspecting neuroendocrine component admix with adenocarcinoma part on the resected specimen microscopy, applying biomarkers including AE 1/3, synaptophysin, and chromogranin A to confirm the diagnosis of MiNEN. The neuroendocrine part was classified as neuroendocrine tumor grade 2 with Ki 67 at 16.5%. To further understand the molecular characterization of this disease, we evaluated mismatch protein expression by staining MLH1, MSH2, MSH6, and PMS2 antibodies. Interestingly, both components lost MLH1 and PMS2 proteins. Her radical surgery followed oxaliplatin/capecitabine adjuvant chemotherapy. The patient is still well after eight cycles of chemotherapy. dMMR gastric MiNENs and dMMR gastric cancer share many clinical and genetic characteristics. Further studies are necessary to survey the role of dMMR in the prognosis and treatment of this entity.

Gastric Mixed Adenoneuroendocrine Carcinoma with Revised Diagnosis after Retrospective Pathologic Review

Gastric mixed adenoneuroendocrine carcinoma (MANEC) is an entity defined by World Health Organization in 2010, which is composed of adenocarcinoma and neuroendocrine neoplasm. This is a very rare type of tumor in the stomach, which is estimated to be one to two per one million people per year on gastrointestinal track. In general, as MANEC often shows a poor prognosis, early diagnosis of the disease is important for achieving a favorable outcome. However, due to its rarity and histological heterogeneity, it is hard to suspect this disease initially, and sometimes this tumor is misdiagnosed as adenocarcinoma. The present case was a 76-year-old man who was initially diagnosed with gastric tubular adenocarcinoma without distant metastasis. Only 1 month after a curative surgery, multiple liver metastases were newly detected. Retrospective pathologic review resulted in a revised diagnosis as a gastric MANEC, and the patient underwent palliative systemic chemotherapy to achieve partial response.

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.

Neoadjuvant and Adjuvant Chemotherapeutic Strategy of Colorectal Mixed Adeno-Neuroendocrine Carcinomas

Mixed adeno-neuroendocrine carcinomas (MANEC) is a rare pathological diagnosis characterized by the presence of both adeno-carcinomatous and neuroendocrine differentiation with each component comprising 30% of the tumor. This literature review is aimed at the extraction of all existing clinical studies and reviews on colorectal MANEC so as to ensure that a suitable chemotherapeutic regimen is chosen to improve survival outcomes and prognosis of the disease. Parallel search strategies were employed to extract past 10 years articles from PubMed, PubMed Central and Google Scholar databases. A total of 30 records consisting of one clinical trial, five retrospective cohort studies, one case control study, one case series, 16 case reports and six review papers were shortlisted. Chemotherapeutic regimens that were administered as an adjuvant and a neoadjuvant therapy were analyzed with their survival outcomes. The overall survival rate of those administered with neoadjuvant and adjuvant therapy can be as high as 57.4% and 69%, respectively. Multiple chemotherapeutic regimens were employed in colorectal MANEC and superiority of one regimen over the other can’t be established. Any drug or combination of drugs that is responsive against either of the MANEC components is found to be effective against the tumor. However, excellent responsiveness has been found with 5-fluorouracil regimens as a neoadjuvant therapy and platinum-based combinations as an adjuvant therapy. XELOX, streptozocin and S1 regimens also prove to be drugs of choice in aggressive and metastasized disease conditions. Our analysis allows for improved chemotherapeutic management of individuals with colorectal MANEC and establishes an increased potential for use of streptozocin therapy in the clinical setting. However, newer drugs like amrubicin require further research prior to describing its efficacy in colorectal MANEC.

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.

Perforated High-Grade Mixed Neuroendocrine Nonneuroendocrine Neoplasm of Cecum: Unusual Presentation of Rare Disease

Mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs) are rare neoplasms of the gastrointestinal tract, where the neuroendocrine as well as the nonneuroendocrine components each comprise at least 30% of the tumor. Of all cases of colorectal malignancies, MiNENs constitute around 3-9.6%, with only a few cases reported to be arising in the cecum. Since majority present with nonspecific clinical and radiological findings, its diagnosis preoperatively is almost impossible and these are usually diagnosed after histopathological examination of the resected specimen. Owing to the rarity of these tumors as well as lack of complete molecular characterization, optimal treatment remains unestablished. We, here, report a rare case of MiNENs of the cecum infiltrating the right psoas muscle and presenting with perforation for which right hemicolectomy and en bloc excision of the involved psoas muscle was done followed by adjuvant chemotherapy.

Metastatic Mixed Adeno-Neuroendocrine Carcinoma of the Colon to the Liver with Multiple Peritoneal Deposits: A Case Report

Patient: Male, 48-year-old

Final Diagnosis: Poorly differentiated mixed adenoneuroendocrine tumor of the colon

Symptoms: Abdominal pain • fatigue • weight loss

Medication: Azathioprine

Clinical Procedure: Colonscopy

Specialty: Oncology • Pathology • Surgery

Subcellular Expression of Maspin in Colorectal Cancer: Friend or Foe

In this review the authors aimed to emphasize the practical value of nuclear expression of the mammary serine protease inhibitor (maspin), also known as serpin B5 protein, in colorectal carcinoma (CRC), from pre-malignant disorders to carcinogenesis and metastasis. As the role of maspin is controversial and not yet understood, the present update highlights the latest data revealed by literature which were filtrated through the daily experience of the authors, which was gained at microscopic examination of maspin expression in CRCs and other tumors for daily diagnosis. Data regarding the subcellular localization of maspin, in correlation with the microsatellite status, grade of tumor dedifferentiation, and epithelial-mesenchymal transition (EMT) phenomenon of the tumor buds were presented with details. An original observation refers to the maspin capacity to mark the tumor cells which are "at the point of budding" that were previously considered as having "hybrid EMT phenotype". It refers to the transitional status of tumor cell that is between "epithelial status" and "mesenchymal status". The second original hypothesis highlights the possible role of maspin in dysregulating the intestinal microbiota, in patients with idiopathic inflammatory bowel diseases (IBD) and inducing IBD-related CRC. The dynamic process of budding and EMT of tumor buds, possible mediated by maspin, needs further investigation and validation in many human CRC samples. The histological and molecular data reveal that synthesis of maspin-based therapeutics might represent a novel individualized therapeutic strategy for patients with CRC.

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.

Mixed adenoneuroendocrine carcinoma (MANEC) of the ampulla of Vater in a Chinese patient: A case report

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumour of the gastrointestinal tract with both epithelial and neuroendocrine components. We describe a case of a 57-year-old man who presented with yellow sclera and dark urine. Contrast-enhanced computed tomography (CT) showed enlargement of the intra and extrahepatic bile ducts and a neoplastic lesion at the end of the common bile duct which was indistinguishable from the adjacent head of the pancreas and duodenum. A pancreaticoduodenectomy was performed and histopathological examination of resected samples showed that tumour was a complex lesion with adenocarcinoma and neuroendocrine components positive for neuroendocrine markers (chromogranin A and synaptophysin) with a Ki-67 labelling index of 40%. The patient was diagnosed with MANEC in the ampulla of Vater with a neuroendocrine carcinoma component of approximately 70%. Ampullary MANECs are highly aggressive tumours with a high risk for distant metastases and a poor prognosis. Therefore, establishing a standard therapeutic strategy is crucial.

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.

[Mixed Neuroendocrine-non-neuroendocrine Neoplasm of the Stomach that is Distributed in Depth on the Same Tumor: Inconsistent with the Definition of Mixed Adenoneuroendocrine Carcinoma in the 2010 World Health Organization Classification of Tumors of the Digestive System]

A mixed adenoneuroendocrine carcinoma (MANEC) of the stomach is a rare disease entity that was first defined by the World Health Organization (WHO) classification (2010) for tumors of the digestive system. According to the WHO classification (2010), MANEC is referred to as a tumor with both neuroendocrine and non-neuroendocrine neoplasms; each component of the tumor should be at least 30%. On the other hand, this cut-off value lacks clinical evidence and does not explain the characteristics and heterogeneity of this tumor. A 66-year-old male diagnosed with early gastric cancer (EGC) at a community hospital was referred to the Kosin University Gospel Hospital for further evaluation of gastric cancer. Esophagogastroduodenoscopy and EUS performed at the Kosin University Gospel Hospital revealed a sub-mucosal tumor-like component. In addition, a re-biopsy revealed a neuroendorine tumor at different depths of the same tumor. The final pathologic-diagnosis through surgery revealed a mixed neuroendocrine- non-neuroendocrine neoplasm, which is inconsistent with the definition of MANEC. Clinicians should consider EUS when a tumor has atypical endoscopic findings, even if EGC has already been diagnosed.

Mixed adenoneuroendocrine carcinoma of the liver: A rare case report

A 55-year-old woman presented with chest and back pain of unknown cause. Contrast-enhanced computed tomography revealed two low-density tumors, sized 4.6 and 4.4 cm, in the hepatic caudate and left inner lobes, respectively. There are multiple enlarged lymph nodes around the abdominal aorta, hepatogastric ligament and gastrosplenic ligament. At the same time, there were multiple enlarged lymph nodes between the portal vein and the vena cava. Upper gastrointestinal endoscopy revealed chronic non-atrophic gastritis and esophagitis (grade B). Endoscopic examination of the lower digestive tract revealed polyps of the colon, diagnosed as tubular adenomas following biopsy and histopathological examination. The patient underwent left three hepatic resection (including left inner lobe, left outer lobe and right anterior lobe resection), abdominal lymph node dissection, right liver tumor radiofrequency ablation, hepatic caudate lobe resection, intestinal adhesion release, vena cava formation, portal vein repair and hilar cholangioplasty. The pathological examination of the resected specimens revealed intrahepatic bile duct carcinoma and hepatic parenchymal neuroendocrine tumor (NET). In addition, liver solid portions consisted of tumor cells with characteristic salt-and-pepper nuclei. Immunohistochemical examination revealed expression of the neuroendocrine marker synaptophysin in this solid component, confirming the diagnosis of NET. Furthermore, the MIB-1 proliferation index of the NET was higher compared with that of the adenocarcinoma, and lymph node invasion by the NET component was detected, indicating a neuroendocrine carcinoma (NEC, or NET G3). The diagnosis of mixed adenoneuroendocrine carcinoma of the liver was confirmed based on the World Health Organization 2010 criteria. Taking into consideration the patient's poor general condition, only symptomatic supportive treatment was administered postoperatively, without chemotherapy. Contrast-enhanced computed tomography at 45 days postoperatively revealed disease progression, with metastases in the liver stump, abdominal lymph nodes, spine and pelvis. The patient remained on symptomatic supportive treatment and succumbed to disease progression 3 months after surgery.

Gastrointestinal mixed adenoneuroendocrine carcinoma (MANEC): An immunohistochemistry study of 13 microsatellite stable cases

BACKGROUND

Mixed adenoneuroendocrine carcinoma (MANEC) is currently included in the category of neuroendocrine carcinomas but the therapeutically management is not yet defined.

AIMS

To present the immunohistochemical (IHC) features of the epithelial mesenchymal transition (EMT) of MANEC.

MATERIALS AND METHODS

The clinicopathological features of 13 consecutive cases of MANEC (6 gastric and 7 colorectal) were correlated with the IHC expression of the biomarkers E-cadherin, β-catenin, N-cadherin, vimentin, maspin, CD44 and S100. In all of the cases open surgery was performed.

RESULTS

All of the cases showed microsatellite stable status, expressed E-cadherin and membrane β-catenin in both components (neuroendocrine and adenocarcinoma) and were negative for N-cadherin, vimentin and S-100. The colorectal MANECs were negative for maspin. In gastric MANECs, maspin showed cytoplasm positivity in the neuroendocrine component and nuclear translocation in the adenocarcinoma cells. CD44 was positive in all of the cases, in both components. No tumor buddings were identified. Three of the 13 patients survived for at least 32 months, all of them showing lymphatic emboli but not lymph node metastases. Pure neuroendocrine lymph node metastases were seen in only four of the cases: one from stomach, two of the ascending colon and two cases of the upper rectum.

CONCLUSIONS

Gastrointestinal MANEC is a microsatellite stable tumor with nodular growth, which components might originate from a CD44-positive stem-like precursor cell. Lymph node status remains the most reliable prognostic parameter and agressivity seems to not be influenced by tumor budding degree or EMT-related features. The histologic aspect of metastatic component (neuroendocrine versus adenocarcinoma) should be included in the histopathological reports and might be used for establishing the proper-targeted therapy of MANEC.

Distribution of Neuroendocrine Marker-Positive Cells in Colorectal Cancer Tissue and Normal Mucosal Tissue: Consideration of Histogenesis of Neuroendocrine Cancer

BACKGROUND

Colorectal neuroendocrine carcinoma (NEC) is a rare disease, and mixed cases with colorectal adenocarcinoma also exist. The histogenesis of this disease remains unclear. We studied the numbers of neuroendocrine marker-positive cells in adenocarcinoma tissue and in normal -mucosal tissue to investigate the relation between adenocarcinoma and NEC and to discuss the histogenesis of NEC.

METHODS

We studied a total of 354 curatively resected cases of stage II or III colon cancer and 36 cases of rectal cancer treated at the Tokai University Hospital between 2007 and 2012. Adenocarcinoma tissue and normal mucosal tissue were immunohistochemically stained with chromogranin A, synaptophysin, and CD56. Cases in which neuroendocrine marker-positive cells were found in cancer tissue were defined as positive. In normal mucosa, the numbers of positive cells per 15 high-power fields (HPF) were counted.

RESULTS

Among the 390 cases, 181 cases had right sided colon cancer, 173 cases had left sided colon cancer, and 36 cases had rectal cancer. The rates of positive staining for chromogranin A, synaptophysin, and CD56 were significantly higher in the right sided colon than in the left sided colon, consistent with the preferred sites of NEC as reported previously. Cells positive for chromogranin A and synaptophysin in normal mucosa were significantly more common in the rectum and the left sided colon than in the right sided colon. No site-specific differences were found for CD56.

CONCLUSIONS

Neuroendocrine marker-positive cells in colorectal cancer tissue are more common in the right sided colon, whereas neuroendocrine marker-positive cells in normal mucosa are more common in the rectum. These results suggest that NEC may arise from preceding adenocarcinomas.

Oncologic outcome of mixed adenoneuroendocrine carcinoma (MANEC): A single center case series

INTRODUCTION

Mixed adeno-neuroendocrine carcinomas (MANEC) are rare tumors of gastrointestinal tract mostly found in stomach. There are very few case reports and case series with location of colon and rectum. We aimed to report our results in the treatment of colorectal MANEC.

METHODS

We performed a prospective analysis of patients with MANEC diagnosis from December 2011 to March 2019 at National Cancer Institute, Lithuania. The demographic information, tumor details, immunohistochemical markers, clinical data, stage, treatment modalities, clinical and oncological outcomes were collected.

RESULTS

Nine patients with a diagnosis of MANEC were found in our center. The average age at diagnosis was 64.8 (48-91) years. Seven out of nine (77.8%) patients underwent surgery. Distant metastases were observed in five (55.6%) patients. The adenocarcinoma and neuroendocrine tumor as a dominant component were equal in all cases. The most common tumor localizations were sigmoid colon in three patients (33.3%) and rectum - three patients, following two in an anal canal, and one in the hepatic flexure of colon. The adenocarcinoma component was poorly differentiated (G3) in six patients and moderately differentiated (G2) in three patients. The neuroendocrine component was G3 in seven patients (77.8%), G2 - in two patients (22.2%). Median follow-up was 17 months with a median survival time of 12.5 months.

CONCLUSION

MANEC is very rare, aggressive, rapidly spreading, usually with poor prognosis disease.

Colorectal neuroendocrine carcinoma: A case report and review of the literature

BACKGROUND

Colorectal neuroendocrine carcinoma (NEC) is a rare tumor that demonstrates aggressive growth pattern with ingrowth into the tract, metastasis to the other organs, and invasion to the surrounding organs; these clinical characteristics result in poor prognosis. Surgical resection appears as an effective approach; however, because it is difficult to accurately diagnose NEC during the early stage and owing to its aggressive growth pattern, development of a reliable standard chemotherapy regimen and management strategies are essential.

CASE SUMMARY

Here, we report the case of patient with NEC showing an aggressive growth pattern that resulted in the rupture of the tumor to the outside the colon after stenting of the internal colonic stenosis. In addition, the tumor invaded into the duodenum, thereby causing duodenal stenosis that required an additional stent in the duodenum. This aggressive growth pattern is one of the main features of the NEC that is different from adenocarcinoma. To clarify the clinical characteristics, we reviewed 60 recently reported cases, including data on tumor location, size, treatment, and prognosis.

CONCLUSION

We consider that the information presented here is of great significance for the diagnosis, treatment, and management of symptoms of the patients with NEC.

Diagnosis of Mixed Adenoneuroendocrine Carcinoma (MANEC) after Neoadjuvant Chemotherapy for Pancreatic and Gastric Adenocarcinoma: Two Case Reports and a Review of the Literature

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumor of the gastrointestinal tract involving both epithelial and neuroendocrine (NE) components, each of which represents at least 30% of the tumor. Because of the low frequency of this histotype, only a few cases have been described. In this report we discuss two cases treated with neoadjuvant chemotherapy: a pancreatic adenocarcinoma and a gastric adenocarcinoma. The histopathological specimens examined after surgery showed an additional NE component with a possible indication of the MANEC histotype. We hypothesize two possible explanations: tumor NE cells are more chemo-resistant than adenocarcinoma cells, and cytotoxic injury induces NE differentiation in tumor cells. The clinical significance and prognostic value of endocrine differentiation, however, remain controversial issues.

Subcellular expression of maspin – from normal tissue to tumor cells

Maspin or SerpinB5, a member of the serine protease inhibitor family, was shown to function as a tumor suppressor, especially in carcinomas. It seems to inhibit invasion, tumor cells motility and angiogenesis, and promotes apoptosis. Maspin can also induce epigenetic changes such as cytosine methylation, de-acetylation, chromatin condensation, and histone modulation. In this review, a comprehensive synthesis of the literature was done to present maspin function from normal tissues to pathologic conditions. Data was sourced from MEDLINE and PubMed. Study eligibility criteria included: Published in English, between 1994 and 2019, specific to humans, and with full-text availability. Most of the 118 studies included in the present review focused on maspin immunostaining and mRNA levels. It was shown that maspin function is organ-related and depends on its subcellular localization. In malignant tumors, it might be downregulated or negative (e.g., carcinoma of prostate, stomach, and breast) or upregulated (e.g., colorectal and pancreatic tumors). Its subcellular localization (nuclear vs cytoplasm), which can be proved using immunohistochemical methods, was shown to influence both tumor behavior and response to chemotherapy. Although the number of maspin-related papers increased, the exact role of this protein remains unknown, and its interpretation should be done with extremely high caution.

Mixed neuroendocrine-non-neuroendocrine carcinoma of gallbladder: case report

Background

Mixed neuroendocrine-non-neuroendocrine tumors (MINEN) of the gallbladder are extremely rare; indeed, the English expert literature reports a mere handful of case reports and case series on this topic. According to the WHO classification of 2010, MINEN are considered to be tumors consisting of two major components, neuroendocrine and non-neuroendocrine, each of which hosts at least 30% of the total cellular population. To date, the etiology and pathogenesis of MINEN have not been precisely determined and the non-specific symptoms generally result in late diagnosis (mainly in the terminal stages of the condition) and contribute to the generally poor prognosis. As far as the management of the disease is concerned, radical surgery plays a crucial role; however, the significance of surgical debulking and biological therapy applying somatostatin analogues has not yet been determined.

Case presentation

A 56-year-old female was referred to our department for a rapidly progressing tumor in the subhepatic area along with the infiltration of S5 and S6 liver segments. With regard to preoperative findings, the tumor appeared as operable, although, during the surgery, an extensive involvement of the hepatoduodenal ligament by the tumor through the lymph nodes was revealed. Due to acute perioperative bleeding from the necrotic tumor, we decided to perform modified resection. Histologically, the tumor was confirmed as MINEN of gallbladder, where the neuroendocrine component was dominant over the non-neuroendocrine component. Six weeks after the discharge, the patient underwent a follow-up CT revealing large recurrence of the disease. Thereafter, the patient was started on systemic therapy with etoposide and carboplatin in combination with somatostatin analogues. Thirteen months after the surgery, the patient is in good clinical condition, and while a recently performed PET/MRI scan revealed a hepatic lesion and hilar lymphadenopathy in full regression, there was a spread of small peritoneal and pleural metastases. The patient remains in the follow-up care.

Conclusions

The occurrence of mixed neuroendocrine-non-neuroendocrine neoplasms is extremely rare. Radical surgery remains the only potentially effective approach to the cure of this disease. The role of biological therapy and debulking in the management of the disease has not yet been precisely defined. In our experience, both of these methods have the potential to positively influence overall survival rates and the postoperational quality of life of patients.

Gastric mixed adenoneuroendocrine carcinoma case report

Mixed adenoneuroendocrine carcinomas are rare tumors that contain both an exocrine and an endocrine component. Since the latest classification by the World Health Organization and with the aid of immunostaining, more mixed adenoneuroendocrine carcinomas are now identified and diagnosed. Nonetheless, our knowledge of these tumors is still limited, notably concerning gastric variants, as the cases reported in the literature are very limited. The clinical and surgical treatment, including the chemotherapy schemes, the prognosis, and recurrence still represent challenges for the medical teams. We present the case of a 62-year-old woman. After an upper endoscopy revealed multiple polyps and a low-grade neuroendocrine tumor, a D2 radical gastrectomy was performed. A low output esophageal anastomotic leak was discovered in the postoperative period and successfully managed. Pathology revealed a gastric mixed adenoneuroendocrine carcinoma, the first case of this kind reported in Ecuador. Patient is doing well and under constant surveillance up until her 13th postoperative month.

A Rare Case of Mixed Adenoneuroendocrine Carcinoma of the Ileocecal Valve

Mixed adenoneuroendocrine carcinoma (MANEC) is an uncommon neoplasm with uncertain pathophysiology. In order to be classified as MANEC, the tumor must contain at least 30% neuroendocrine cells and 30% adenocarcinoma. The standardization of MANEC treatment has historically been difficult due to the lack of diagnostic histological classification. In 2010, the World Health Organization (WHO) finally recognized this uncommon condition as a specific colon cancer entity in the hopes of better specifying treatment options in the future.

We present a case of high-grade MANEC of the cecum with metastasis in 3/10 lymph nodes to further characterize the diagnostic modalities and treatment options of the disease. MANECs only account for 3%-9.6% of all colorectal cancers and only eight cases have been reported in the cecum to date, making the following case report exceptionally rare.

Mixed adenoneuroendocrine carcinoma of the colon and rectum

Mixed adenoneuroendocrine carcinoma (MANEC) are rare cancers of the gastrointestinal (GI) and pancreatobiliary tract. They are characterized by the presence of a combination of epithelial and neuroendocrine elements, where each component represents at least 30% of the tumour. Review of literature and consolidation of clinicopathological data. Sixty-one cases of colorectal MANEC have been reported in literature and one seen in this centre. The median age of the patients affected was 61.9 ± 12.4 years (20-94 years). Male to female ratio is 1.0:1.2. Presentations were similar to other colorectal malignancies. 58.0% of colorectal MANECs were found in the right colon, 8.1% cases in the transverse, 16.1% in the left colon, 16.1% in the rectum. These tumours appeared invasiveness 79.1% were T3-T4. Over 90% of cases were presented with metastatic disease. The majority of patient underwent surgical resection of the primary cancer (96.6%). Of these, 10 operations (17.9%) were emergency operations due to obstruction, perforation, or bleeding. Three patients received first line palliative care. In eight cases (13.8%), patients underwent adjuvant chemotherapy. The median overall survival after diagnosis was 10 ± 2.4 months (95% CI: 5.37-14.64 months). MANECs are rare but aggressive colorectal cancers. Surgical resection of localized disease with adjuvant chemotherapy appears to significantly improve survival in small case series. Further understanding through the sharing of experiences is required.

Cystic mixed adenoneuroendocrine carcinoma of the pancreas: A case report

•

There are few reports about pancreatic MANEC with cystic features.

•

Mixed tumor of the pancreas may arise from totipotent stem cells.

•

The treatment strategy is unclear, but surgery may be the first choice if possible.

Introduction

Pancreatic mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumor. We report herein a case of pancreatic MANEC with cystic features.

Presentation of case

A 67-year-old woman presented with jaundice. A CT scan revealed an 18-mm mass at the pancreatic head that obstructed the common bile duct and another 35-mm cystic lesion containing a mural nodule in the pancreatic body, which was suspected to be an intraductal papillary mucinous carcinoma. A biopsy of the head mass led to the diagnosis of adenocarcinoma. The patient underwent pancreatoduodenectomy, and the body cyst was resected with the head mass. A histopathological analysis revealed that the body cyst had two components, ductal adenocarcinoma and neuroendocrine tumor. We diagnosed the cystic tumor as MANEC.

Discussion

Cases of MANEC have been reported as originating from the stomach, small intestine, and colon, but pancreatic MANEC is rare. The histogenesis and the therapeutic strategy for pancreatic MANEC are controversial.

Conclusion

The clinicopathological features of pancreatic MANEC remain unclear; therefore, more reports of cases of pancreatic MANEC are necessary for a complete analysis.

Management of MANEC of the colon and rectum: A comprehensive review of the literature

Mixed adeno-neuroendocrine carcinoma (MANEC) is a rare pathological diagnosis recently acknowledged by the World Health Organization in 2010. MANEC is a neoplasm characterized by significant histological heterogeneity and is characterized by the simultaneous presence of both adenocarcinomatous and neuroendocrine differentiation; their definition includes each component found in at least 30% of the tumor. Colorectal MANEC constitutes an uncommon type of malignant tumor. The true prevalence of colorectal MANEC has not been precisely defined and published studies are limited to case reports and small case series. The aim of the present review was to accumulate the existing evidence on colorectal MANEC with special attention to the clinicopathological characteristics, management and survival rates of patients diagnosed with this malignancy. A total of 20 studies (16 case reports and 4 retrospective cohorts) reported outcomes for patients with colorectal MANEC and were finally considered eligible for analysis. The results of the present study show that patients with early stage MANEC have more favorable survival compared to those diagnosed in advanced stages. Due to its neuroendocrine nature, which is characterized by rapid progression, MANEC is diagnosed in advanced stages in the majority of cases and thus potentially explains the poor survival rates. Because of its aggressive nature and high recurrence rate, adjuvant chemotherapy constitutes a critical part of the treatment and significantly improves survival. Further larger studies are needed in order to establish guidelines for the treatment of these rare lesions.

A case of mixed adenoneuroendocrine carcinoma (MANEC) arising in Barrett's esophagus: literature and review

Background

Mixed adenoneuroendocrine carcinoma (MANEC) is defined as a neoplasm composed of both exocrine and endocrine carcinomas, each comprising at least 30% of the tumor. MANEC can occur in various organs of the gastrointestinal tract, including the esophagus, stomach, and colon. We herein provide the first case report of surgically resected MANEC arising in Barrett’s esophagus (BE).

Case presentation

A 70-year-old man presenting with abdominal pain was referred to our hospital. Upper endoscopy showed a type 0-IIa + IIc elevated lesion adjacent to BE. According to a biopsy specimen, the elevated lesion was diagnosed as adenocarcinoma with neuroendocrine differentiation. No lymphatic or distant metastasis was detected in the preoperative examination. Laparoscopic distal esophagectomy and proximal gastrectomy were performed, and a diagnosis of MANEC in BE was determined according to the surgically resected specimen.

Conclusions

A very rare case of MANEC in BE was detected. BE can be the origin of esophageal MANEC as well as adenocarcinoma. Due to the small number of esophageal or esophagogastric MANEC cases reported, further accumulation of such cases is necessary to recommend an optimal management strategy for esophageal or esophagogastric MANEC.

Mixed adenoneuroendocrine carcinoma in the stomach: a case report with a literature review

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare disease that was first defined in the 2010 World Health Organization classification of endocrine tumors. We present the case of a 65-year-old man with an ulcerative depressed lesion measuring 3 cm in diameter and found in the lower gastric body. It was diagnosed as a MANEC, and we performed subtotal gastrectomy with D2 lymph node dissection. The patient is still alive, and no recurrence was observed at a 12-month follow-up. Most MANECs tend to have a poor prognosis. Curative resection, including an adequate lymph node dissection, should be considered, and intense follow-up is needed.

Long-term disease free survival of gastric mixed adenoneuroendocrine carcinoma treated with multimodality therapy: A case report

Gastric mixed adenoneuroendocrine carcinoma, a rare malignant type of stomach tumor, is composed of components of adenocarcinoma and neuroendocrine tumor. This type of neoplasm usually has a poor prognosis since both components are malignant. A 65-year-old male presented with norexia, epigastric distention, abdominal and lumbar pain. Contrast computed tomography scan of the abdomen verified multiple lesions merged into a large mass. Histolopathological examination of the specimen from digestive endoscopy was verified to be gastric mixed adenoneuroendocrine carcinoma. The patient received a multimodality treatment of chemotherapy, surgical resection with radiotherapy and still remains alive with no evidence of metastasis or recurrence for over 5 years. The authors suggest that multimodality therapy may be beneficial and necessary to effictively treat mixed adenoneuroendocrine carcinoma.

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.

Two patients with rare mixed adenoneuroendocrine carcinomas of the rectum

Mixed adenoneuroendocrine carcinomas of the gastrointestinal tract are until today poorly understood and thus very challenging for interdisciplinary therapy. We herewith report the first case series of patients with a primary mixed adenoneuroendocrine carcinoma of the rectum. Both cases were initially diagnosed as adenocarcinoma and only secondarily with mixed adenoneuroendocrine carcinoma and had a poor outcome due to a rapid tumor progression and resistance to chemotherapy. A 65-year-old female presented with local tumor recurrence and hepatopulmonary metastasis 1 year after primary surgery for adenocarcinoma of the rectum and consecutive radiochemotherapy regimen. Fluorouracil (5-FU) was followed by bevacizumab- and capecitabine-based chemotherapy but had to be discontinued due to side effects and progressive disease. Progressive local pain syndrome accompanied by recurrent bleeding episodes led to a local tumor-debulking operation. Afterward, mixed adenoneuroendocrine carcinoma as the underlying diagnosis in the final histopathological examination was detected. The patient died 3 months after the operation in the context of a fulminant tumor progress. A 63-year-old male patient underwent neoadjuvant radiochemotherapy and laparoscopic rectum resection. After 5 months, postoperative oxaliplatin/capecitabine-based adjuvant chemotherapy was switched to carboplatin/etopsid due to a progressive polyneuropathy and biopsy-proven pulmonary metastasis. The patient then had to be switched to local radiation of cerebral metastases and Topotecan due to cerebral bleeding episodes but died 18 months after the initial diagnosis. In conclusion of our case series, mixed adenoneuroendocrine carcinomas of the rectum should be considered as a rare but aggressive tumor entity. An early and detailed histopathological diagnosis is required in order to establish an individual interdisciplinary treatment concept.

Clinicopathological features and prognosis of gastric mixed adenoneuroendocrine carcinoma

Gastric mixed adenoneuroendocrine carcinomas (MANECs) are rare malignant tumors. This study aimed to investigate the clinicopathological features, diagnosis, prognosis, and treatment outcome in gastric MANECs patients. Clinicopathological data and the archived slides of 40 cases of MANEC patients were retrospectively reviewed. Immunohistochemistry (IHC) staining was performed to detect expression of synaptophysin (Syn), chromogranin A (CgA), CD56, CKpan, CK7, CK8/18, carcinoembryonic antigen (CEA), CK5/6, P40 and Ki-67. Hematoxylin and eosin staining demonstrated exocrine and neuroendocrine components, each accounting for at least 30% of the whole lesion. Exocrine components diffusely expressed epithelial markers CKpan, CK7, CK8/18, and CEA and endocrine components widely expressed at least one of the markers Syn, CgA, and CD56. Ki-67 index and mitosis determined the endocrine component grade as G3. Thirty-three of 40 patients were successfully followed up for 3 to 105 months with median survival of 12 months. Survival analysis showed a significant difference in prognosis with regard to patient's age, disease stage, tumor relapse status, and distant metastasis status. In conclusion, patient's age, disease stage, tumor relapse status, and distant metastasis status are important contributors to poor prognosis. Old patients with advanced stage, recurrence, or metastasis to the liver, pancreas or other distant organs show a poor prognosis.

Mixed Adenoneuroendocrine Carcinoma of the Gastroesophageal Junction: A Rare Find

Neoplastic lesions that demonstrate neuroendocrine features are rare. However, esophageal tumors containing both adenocarcinomatous and neuroendocrine components are exceedingly rare. Mixed adenoneuroendocrine carcinomas (MANECs) are gastrointestinal tumors with both adenocarcinomatous and neuroendocrine differentiation. They have a tendency for early metastases but clinically manifest relatively late. Imaging studies are often nonspecific with regard to tumor type, and a histopathologic study of biopsy material is required for definitive diagnosis. The overall prognosis is poor. The current report describes a rare case of gastroesophageal MANEC tumor, with approximately 60% neuroendocrine and 40% adenocarcinomatous components. Since there is a dearth of concrete management guidelines for MANECs, we present possible management options to add to the existing literature.

An extremely rare case of Epstein-Barr virus-associated gastric carcinoma with differentiation to neuroendocrine carcinoma

Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVGC) is defined as a neoplasm comprising monoclonal proliferation of EBV-infected gastric epithelial cells. Although the typical histology is gastric carcinoma with lymphoid stroma (GCLS), the histologic features of the tumor vary. We report herein the case of a 78-year-old man with multiple simultaneous EBVGCs revealing different histopathologic morphologies; one was mixed adenoneuroendocrine carcinoma (MANEC), and the other was GCLS. Both tumor types exhibited positive results for EBV in situ hybridization. To the best of our knowledge, this represents the first report of EBVGC showing neuroendocrine differentiation. Immunohistochemistry also revealed a loss of gastrointestinal features, including CDX2, MUC5AC, and MUC6 expression, among tumor cells from the neuroendocrine component of the MANEC. We describe the pathologic features of this rare neoplasm and discuss the mechanisms underlying the neuroendocrine differentiation of EBVGC cells, along with providing a brief review of the literature.

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.

Mixed adenoneuroendocrine carcinoma (MANEC) of the gastroesophageal junction: a case report and review of the literature

Esophageal cancer is the fourth most common neoplasm of the gastrointestinal tract. It is responsible for 1.7% of all deaths related with cancer. The two main types of esophageal cancer are squamous cell carcinoma and adenocarcinoma. Other types of esophageal cancer are uncommon. We present a 57-year-old man admitted to the hospital with nausea and vomiting due to a high-grade malignant mixed adenoneuroendocrine carcinoma of the gastroesophageal junction. The patient underwent Ivor-Lewis esophagectomy and adyuvant chemoradiotherapy. At 8-month follow-up he was alive without evidence of recurrence.

Gastric Pouch Mixed Adenoneuroendocrine Carcinoma With a Mixed Adenocarcinoma Component After Roux-en-Y Gastric Bypass

The Roux-en-Y gastric bypass is one of the most common procedures currently performed for surgical treatment of patients with severe obesity. Gastric cancer after bariatric surgery is not common, with most of them arising in the excluded stomach. Gastric mixed adenoneuroendocrine carcinomas are a rare type of stomach malignancy, composed of both adenocarcinoma and neuroendocrine tumor-cell components, with the latter comprising at least 30% of the whole neoplasm. In this article, we report a unique case of a mixed adenoneuroendocrine carcinoma with a mixed adenocarcinoma (tubular and poorly cohesive) component arising in the gastric pouch of a patient who underwent previous Roux-en-Y gastric bypass for glycemic control. Since stomach cancer is not usual in patients who have formerly undergone bariatric surgery and symptoms tend to be nonspecific, such diagnosis is often rendered at an advanced stage. Full assessment of these patients when presenting such vague symptoms is critical for an early cancer diagnosis.

Cervical Carcinoma With Divergent Neuroendocrine and Gastrointestinal Differentiation

Neuroendocrine carcinomas of the uterine cervix are rare tumors with aggressive behavior. They comprise <4% of cervical carcinomas. They may coexist with both adenocarcinoma and squamous cell carcinoma of cervix. Signet ring carcinoma of cervix is a rarer entity and less than 20 cases have been described in the literature. We present a case of a 34-year-old female who presented with systemic thrombosis, splenic mass and a cervical mass which on biopsy showed divergent differentiation of primitive large cell neuroendocrine carcinoma with signet ring cells. The cervical tumor was positive for human papilloma virus 16/18 by in situ hybridization, confirming cervical origin of the tumor. This unusual presentation and morphology needs to be recognized and appropriately evaluated when patients present with tumors of unknown origin in metastatic sites.

A Case Report: Gastric Mixed Neuroendocrine-Nonneuroendocrine Neoplasm with Aggressive Neuroendocrine Component

Mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN) is defined as mixed epithelial neoplasms composed of both neuroendocrine and nonneuroendocrine components with variable proportions for each component. Neuroendocrine component can show morphological features including well- or poorly differentiated neuroendocrine neoplasms and nonneuroendocrine component can present different tumor types depending on the site of origin. Recently, studies of tumors have shown that MiNENs are not as rare as our traditional belief, due to the wide application for immunohistochemistry. However, our knowledge of MiNENs is still limited. There is no universal consensus about nomenclature, classification, and guideline of treatment. Hereby, we would like to present a case report of gastric MiNEN with aggressive neuroendocrine component to contribute a small part towards common understanding of gastric MiNENs.