Endocrine cell carcinomas of the colon and rectum: a clinicopathological evaluation. Clin J Gastroenterol. 2016;9:1-6. [PMID: 26699873 DOI: 10.1007/s12328-015-0623-6]

Multiple Rare Primary Malignancies: A Mixed Squamous Neuroendocrine Adenocarcinoma of the Cervix, Metastasized Carcinosarcoma and Extramammary Vulvar Paget's Disease Case Report

The occurrence of more than one primary malignant tumor in a single patient is rare. Multiple primary malignancies can pose difficulties in differential diagnosis between primary tumors and metastasis. Here, we present a case report with multiple primary malignancies. The patient is a 45-year-old female who was diagnosed with cervical mixed squamous neuroendocrine adenocarcinoma, metastasized carcinosarcoma and extramammary vulvar Paget's disease. The patient was first diagnosed with a microinvasive squamous cervical carcinoma in situ. After a few months, the amputation of a small residual tumor and histological evaluation revealed an IA1-stage poorly differentiated (G3) mixed squamous and neuroendocrine cervical adenocarcinoma. After two years, the disease had progressed and biopsies from altered sites were taken. Histological diagnosis from an ulcerated vulvar region revealed extramammary vulvar Paget's disease. A biopsy from vagina polyp revealed an earlier diagnosed mixed squamous and neuroendocrine cervical adenocarcinoma. However, histological diagnosis from an inguinal lymph node biopsy was unexpected and revealed carcinosarcoma. It indicated either the development of another primary malignancy, or an unusual spread of metastasis. Clinical presentation as well as diagnostic and treatment challenges are discussed in this case report. This case report shows that multiple primary malignancy cases are difficult to manage both for clinicians and the patient because the therapeutic options can become limited. This complex case was managed by a multidisciplinary team.

A case of strongly suspected Lynch syndrome with colorectal neuroendocrine carcinoma

Background

Neuroendocrine cell carcinomas (NEC) of the colon and rectum are uncommon, representing ~ 0.1% of all colorectal carcinomas. They are associated with a much worse prognosis compared to adenocarcinoma of the colon and rectum, as death occurs in approximately half of all patients within 1 year. Lynch syndrome (LS) is the most common cause of inherited colorectal cancer, accounting for 2–4% of newly diagnosed colorectal cancer cases. This case is extremely rare which was strongly suspected LS as the background, and NEC as the histological type of colorectal cancer.

Case presentation

The patient was a 44-year-old man presenting with vomiting as the main complaint. He had undergone ileocecal resection for cecal cancer at age 29. The diagnosis was obstructive descending colorectal cancer, and colonoscopy revealed tumors in the rectum and sigmoid colon in addition. Due to multiple occurrences of colorectal cancer and its prevalence in the patient’s family, LS was suspected. The operation which was a subtotal proctocolectomy was performed. Pathological analysis revealed complete curative resection and the descending colon cancer of the obstructed portion was at the most advanced pathological Stage IIIC in UICC TNM classification, and the tissue type was a NEC. The Ki-67 index was 70%. The results of the microsatellite instability (MSI) test showed high-frequency MSI. The BRAF V600E variant was negative. The immunoexpression of MLH1 was positive, MSH2 was negative, PMS2 was positive, and MSH6 was negative.

Conclusions

Extended surgery is recommended for incipient colorectal cancer in LS cases in order to reliably reduce the risk of developing metachronous colorectal cancer. The survival outcome of surgery alone on digestive tract NECs, even locoregional lesions that are completely resection, is extremely poor. It is currently unclear if digestive tract NECs develop more readily in patients with LS. The accumulation of additional cases is necessary.

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.

Mixed neuroendocrine–nonneuroendocrine neoplasms of the gastrointestinal system: An update

Mixed neuroendocrine-nonneuroendocrine neoplasms (MiNENs) of the digestive tract are a rare heterogeneous group of tumors that present many challenges in terms of diagnosis and treatment. Over the years, the diagnostic criteria, classification, and clinical behavior of these tumors have been the subjects of ongoing debate, and the various changes in their nomenclature have strengthened the challenges associated with MiNENs. This review is performed to provide an understanding of the key factors involved in the evolution of the designation of these tumors as MiNEN, highlight the current diagnostic criteria, summarize the latest data on pathogenesis and provide information on available treatments. Moreover, this work seeks to increase the awareness about these rare neoplasms by presenting the clinicopathological features and prognostic factors that play important roles in their behavior and discussing their different regions of origin in the gastrointestinal system (GIS). Currently, the MiNEN category also includes tumors in the GIS with a nonneuroendocrine component and epithelial tumors other than adenocarcinoma, depending on the organ of origin. Diagnosis is based on the presence of both morphological components in more than 30% of the tumor. However, this value needs to be reconfirmed with further studies and may be a limiting factor in the diagnosis of MiNEN by biopsy. Furthermore, available clinicopathological data suggest that the inclusion of amphicrine tumors in the definition of MiNEN is not supportive and warrants further investigation. The diagnosis of these tumors is not solely based on immunohistochemical findings. They are not hybrid tumors and both components can act independently; thus, careful grading of each component separately is required. In addition to parameters such as the metastatic state of the tumor at the time of diagnosis and the feasibility of surgical resection, the aggressive potential of both components has paramount importance in the choice of treatment. Regardless of the organ of origin within the GIS, almost MiNENs are tumors with poor prognosis and are frequently encountered in the elderly and men. They are most frequently reported in the colorectum, where data from molecular studies indicate a monoclonal origin; however, further studies are required to provide additional support for this origin.

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.

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.

Mixed neuroendocrine-non-neuroendocrine neoplasm with squamous cell carcinoma covered by tubulovillous adenoma in the rectum

A variety of histologies is often mixed in neuroendocrine carcinoma (NEC) called mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN). However, tumors consisting of both large-cell NEC and squamous cell carcinoma (SCC) are rare. NEC of the large intestine is aggressive; however, an ideal treatment strategy has not been established. In this study, we have reported a case of rectal MiNEN containing large-cell NEC and SCC that was covered by tubulovillous adenoma. A 73-year-old man was referred to our hospital for the treatment of an upper rectal tumor. The results of preoperative biopsy indicated tubulovillous adenoma, whereas computed tomography revealed multiple liver tumors and swollen lymph nodes around the rectum. Laparotomy was performed because of severe dyschezia caused by rectal stenosis. Hartmann's operation was performed because of peritoneal metastases. Histopathological examination of the rectal tumor revealed MiNEN containing large-cell NEC, SCC, well-differentiated adenocarcinoma, and tubulovillous adenoma covering the surface of the tumor. The patient died 73 days after surgery due to liver metastases. It is important to consider NEC in the differential diagnosis and tissue sampling should be performed to ensure appropriate management when pathological findings and clinical diagnosis do not match. More research is required to determine the ideal treatment for these rare and aggressive tumors.

Dilemmas in Diagnosis and Management of Gastroenteropancreatic Mixed Neuroendocrine Non-neuroendocrine Neoplasms: First Single-Centre Report from India

PURPOSE

Mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) is a rare neoplasm comprising of exocrine and neuroendocrine elements, each representing ≥ 30% lesion. It is commonly misdiagnosed as adenocarcinoma or grade-3 neuroendocrine neoplasm (NEN). Management is not well-defined.

METHODS

Retrospective analysis of prospectively entered data at our centre from January 2011 to January 2018 revealed 16 MiNENs off 130 neuroendocrine neoplasms (NENs). These were analysed for demographics, clinicopathological characteristics, management strategies and prognosis.

RESULTS

Four out of 16 patients, metastatic at presentation, were started on chemotherapy. Eleven of remaining 12 patients had pre-operative biopsy. Only two were diagnosed MiNEN. Four patients (33.34%) received 5-fluorouracil (5-FU)-based neoadjuvant chemotherapy and underwent curative surgery with adjuvant cisplatin+etoposide (Cis-Eto). Out of these, two patients (16.6%) developed metastasis and were shifted to capecitabine+temozolomide (Cap-Tem). Six patients (50%) with neuroendocrine-dominant MiNEN received adjuvant Cis-Eto after surgery. Two (16.6%) developed metastases for which Cap-Tem was started. One of them developed locoregional and liver metastasis. Three patients (25%) have succumbed to progressive disease, three (25%) are on treatment, and six (50%) are disease-free at 4-30 months.

CONCLUSION

Preoperative diagnosis of MiNEN is challenging, and it needs quality histopathological examination and immunohistochemistry. The 30% criteria is therapeutically insignificant, and treatment based on most aggressive component is prognostically more relevant. Neoadjuvant 5-FU-based regimens may downstage adenocarcinoma-dominant tumours. There are no guidelines on adjuvant Cis-Eto. Cap-Tem can be considered second-line chemotherapy. Poor survival is reported irrespective of site of origin and adjuvant therapy.

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.

Clinical implications of mismatch repair deficiency screening in patients with mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN)

INTRODUCTION

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) are rare tumors, mainly encountered in the gastroenteropancreatic tract. Based on the limited available data, MiNEN is usually a highly aggressive neoplasm combining a high-grade neuroendocrine and a non-neuroendocrine component, associated with a poor prognostic outlook. Deficient DNA mismatch repair (MMR) results in microsatellite instability, which is a useful screening marker for identifying patients with Lynch syndrome and a prognostic factor for chemotherapeutic interventions. Little information on MMR status in MiNEN is available in published studies. Therefore, the purpose of this study was to explore the status and putative role of MMR on MiNEN.

METHODS

We investigated the MMR status in 44 cases and characterized their clinicopathological features and prognoses. Immunohistochemistry was performed for four mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2).

RESULTS

Mean age at diagnosis was 61 years, and 75% of the patients were male. Lymph node metastases were observed in 14 (35.9%) patients. The most common tumor localizations were gastric (28 patients, 63.6%). Lack of immunohistochemical expression of MMR proteins was shown in 38.6% of cases. The common deletion rates of one or more proteins were 29.4% (5/17) for MLH1/PMS2 and 23.5% (4/17) for MLH1. Correlation between clinicopathological parameters showed that MMR deficiency was significantly associated with early TNM stage and better prognoses in patients with MiNEN.

CONCLUSION

MiNENs showed frequent losses of MMR protein expression, which contributes to the knowledge of the pathological and clinical aspects of MiNEN tumors.

Successful Treatment of a Mixed Neuroendocrine-Nonneuroendocrine Neoplasm of the Colon with Metastases to the Thyroid Gland and Liver

Patients with mixed neuroendocrine-nonneuroendocrine neoplasms (MiNENs) of the colon have poor prognosis. Herein, we report a patient with MiNEN of the colon with metastases to the liver and the thyroid gland, with long-term survival. A 45-year-old man presented with anterior neck swelling. Histopathological examination of the thyroid tumor revealed neuroendocrine carcinoma (NEC), suggesting that a primary NEC in another organ had metastasized to the thyroid gland. Computed tomography to identify a primary NEC revealed two tumors: one in the liver and one in the transverse colon. A biopsy revealed that the histopathology of the liver and colon tumors was NEC and adenocarcinoma, respectively. Thereafter, the patient underwent surgical resection of the colon tumor and was finally diagnosed as colon MiNEN with metastases to the thyroid and liver. The surgical resection of the metastatic liver tumor was performed after several courses of systemic chemotherapy, and the patient survives presently without any recurrence for approximately seven years after the diagnosis. Surgical resection of each metastatic lesion combined with systematic chemotherapy apparently improved the prognosis of MiNEN of the colon with distant metastases.

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.

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.

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.

Metastatic mixed adenoneuroendocrine carcinoma of the liver successfully resected by hepatic trisectionectomy following chemotherapy: A case report

The chemotherapy guidelines for mixed adenoneuroendocrine carcinoma (MANEC) remain poorly defined, and prognosis remains dismal. In this case, we successfully performed resection after FOLFOX for unresectable metastatic MANEC of the liver. Thus, chemotherapy for adenocarcinoma may be effective for MANEC.

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.

Mixed Neuroendocrine Carcinoma and Squamous Cell Carcinoma of the Colon: Case Report and Literature Review

Neuroendocrine carcinoma (NEC) of the colon is very rare, and squamous cell carcinoma (SCC) of colon cancer is rare. We recently treated a patient with both NEC and SCC that initially presented as multiple unresectable liver and lung metastases. A 68-year-old Japanese man was referred to our hospital because of diarrhea with descending colon cancer obstruction. He underwent a left colectomy. Based on immunohistochemistry results, we diagnosed mixed NEC and SCC, the primary lesion location of which was probably the lung in the final pathologic examination. He began systemic palliative chemotherapy with CDDP and CPT-11. After 3 months of treatment, shown the progressive disease, we started CDDP and VP-16. The patient was not eligible for additional chemotherapy after 2 months.

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.

结肠神经内分泌瘤G2一例个案报道并文献复习

神经内分泌瘤是一类起源于神经内分泌细胞, 发病率低且具有分子和生物学行为异质性的肿瘤. 现报道一例右半结肠神经内分泌瘤G2伴多发淋巴结转移患者, 以期对临床工作者有所帮助.

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.

Short article: A randomized-controlled study of sitagliptin for treating diabetes mellitus complicated by nonalcoholic fatty liver disease

BACKGROUND

This study aimed to evaluate the efficacy and safety of sitagliptin for treating Chinese patients with type 2 diabetes mellitus (T2DM) with nonalcoholic fatty liver disease (NAFLD).

METHODS

In total, 72 Chinese T2DM patients with NAFLD were divided randomly into two groups of 36 patients each group. All 72 patients were assigned to receive either sitagliptin or diet and exercise for 52 weeks between January 2013 and December 2015. The outcomes' measurements included serum levels of hemoglobin A1c, fasting plasma glucose, aspartate aminotransferase, and alanine aminotransferase.

RESULTS

Seventy patients completed the study. Sitagliptin showed greater efficacy than the diet and exercise in decreasing the hemoglobin A1c and fasting plasma glucose levels at weeks 13, 26, 39, and 52. In addition, no significant changes in the average aspartate aminotransferase and alanine aminotransferase levels were found during the 52-week follow-up in both the sitagliptin and the control groups.

CONCLUSION

The results of this study indicate that sitagliptin is an effective and safe treatment for patients with T2DM and NAFLD.

High-Grade Mixed Adenoneuroendocrine Carcinoma in the Cecum: A Case Report

Gastrointestinal neoplasms with an exocrine and a neuroendocrine component are rare. Such neoplasms are called “mixed adenoneuroendocrine carcinomas” (MANECs) according to the most recent World Health Organization classification of gastrointestinal tract neoplasms. MANECs have no specific findings that distinguish them from pure adenocarcinomas. In addition, the optimal management strategy of MANECs is largely unknown. We describe the case of a 32-year-old man with dizziness and abdominal bloating. A cecal mass was suspected based on an image study done at a local clinic. We evaluated the cecal mass by using colonoscopy, contrast enhanced computed tomography of the abdomen, positron emission tomography-computed tomography, and laboratory studies. The patient underwent a right hemicolectomy and adjuvant chemotherapy. The final histopathological diagnosis was a high-grade MANEC of the ascending colon, tumor stage T3N2M0.

Clinicopathological and Prognostic Evaluations of Mixed Adenoneuroendocrine Carcinoma of the Colon and Rectum: A Case-Matched Study

BACKGROUND

Mixed adenoneuroendocrine carcinoma of the colon and rectum is a very rare type of tumor.

OBJECTIVE

The aim of the present study was to evaluate the clinicopathological characteristics and prognosis of mixed adenoneuroendocrine carcinomas of the colon and rectum.

DESIGN

This was a retrospective case-matched analysis (from March 2007 to December 2013).

SETTINGS

This study was conducted at Yokosuka Kyosai Hospital.

PATIENTS

One thousand three hundred six consecutive patients with a preoperative diagnosis of colorectal cancer and who underwent tumor resection were enrolled in the present study. Each patient diagnosed with mixed adenoneuroendocrine carcinoma was 1:2 matched with 2 counterparts who had been diagnosed with adenocarcinoma.

INTERVENTION

Immunohistochemical staining for neuroendocrine markers (chromogranin A, synaptophysin, and CD56) was performed. Cases in which the neuroendocrine component accounted for >30% of the tumor were diagnosed as mixed adenoneuroendocrine carcinomas.

RESULTS

Among 1306 patients, 42 patients (3.2%) were diagnosed with mixed adenoneuroendocrine carcinoma and were compared with 84 patients with adenocarcinoma who had been randomly case matched. The average Ki-67-labeling index value was 78.0% (range, 30.0%-99.0%). Chromogranin A, synaptophysin, and CD56 positivity were observed in 42.9% (18/42), 81.0% (34/42), and 33.3% (14/42) of the tumors. Both the disease-free survival and overall survival were significantly worse for mixed adenoneuroendocrine carcinoma than for adenocarcinoma. Ten patients underwent treatment with oxaliplatin-based chemotherapy. The response rate was 40.0%; the median progression-free survival and overall survival were 6.3 months and 18.1 months.

LIMITATIONS

This was a retrospective single-institution study that included a limited number of cases. The treatment regimens used included different types of oxaliplatin-based chemotherapy.

CONCLUSION

Mixed adenoneuroendocrine carcinoma of the colon and rectum has a poor prognosis after curative resection and should be distinguished from adenocarcinoma.

Mixed Adenoneuroendocrine Carcinoma Causing Colonic Intussusception

Colonic intussusception is a rare cause of intestinal obstruction in adults and is caused by a malignant lesion in about 70% of cases. Early diagnosis and treatment are essential. We present a 64-year-old male patient with right colonic intussusception caused by a mixed adenoneuroendocrine carcinoma (MANEC), presenting as a giant pedunculated polyp (54 mm of largest diameter). The patient underwent right colectomy with primary anastomosis and adjuvant chemotherapy. The diagnosis of intussusception of the colon in adults is difficult because of its rarity and nonspecific clinical presentation. In this case, the cause was a rare histological type malignant tumor (MANEC).