Mixed adenoneuroendocrine carcinoma of the colon and rectum

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

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

Establishment and validation of a prognostic nomogram for patients with colorectal neuroendocrine carcinoma

BACKGROUND

Colorectal neuroendocrine carcinoma is a relatively rare tumor, for which a prognosis prediction model is lacking. Based on the data from Surveillance, Epidemiology, and End Results (SEER) database and Fujian Cancer Hospital, the study constructed and validated a prognostic nomogram to assess overall survival of patients with colorectal neuroendocrine carcinoma(CRNEC).

METHODS

We extracted data of patients diagnosed with CRNEC from the SEER database. These patients were randomly divided into a training cohort(N = 1425) and an internal validation cohort(N = 612). Data of patients diagnosed with CRNEC in Fujian Cancer Hospital was collected as an external validation cohort(N = 54). A prognostic nomogram was established. The performance of the nomogram was assessed with ROC curve, C-index and calibration curve. Decision curve analysis(DCA) and ROC curve were used to compare the prediction efficacy of nomogram with the seventh edition of the TNM classification of the American Joint Commission of Cancer.

RESULTS

Nine variables were identified as independent predictors. Nomogram were established by the nine variables. AUC of the nomogram in predicting 1-, 3- and 5-year OS were 0.900, 0.912 and 0.915 in training cohort, 0.900, 0.925 and 0.919 in internal validation cohort, 0.900, 0.903 and 0.928 in external validation cohort. C-index were 0.845, 0.854 and 0.837. Calibration curves overlapped well with reference lines. Compared with the AJCC TNM staging system, the nomogram performed more effectively. Patients classified into low-risk and high-risk groups by the nomogram scores and performed well in stratification.

CONCLUSION

The prognostic nomogram established and validated in our study can accurately and effectively predict the prognosis of patients with CRNEC.

Clinicopathological characteristics of mixed neuroendocrine-non-neuroendocrine neoplasms in gastrointestinal tract

BACKGROUND

In 2019, the World Health Organization (WHO) classification system updated the definition of mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs), previously known as mixed adenoneuroendocrine carcinomas (MANECs). The clinicopathological characteristics of this new definition remains to be clarified.

METHODS

We analyzed the clinical data of 43 patients diagnosed with MiNENs in Wuhan Union Hospital from 2011 to 2020 according to the definition of MiNENs proposed in 2019.

RESULTS

Among the 43 patients with MiNENs, the top two most common sites were stomach and colon, and 69.8% were males. Nearly half (21/43) of the patients were diagnosed at TNM stage III, and about 53.5% (23/43) of patients were the neuroendocrine neoplasm dominant type. Among the non-neuroendocrine tumor components of 43 MiNENs patients, adenocarcinoma accounted for 95.3% (41/43) and squamous cell carcinoma accounted for 4.7% (2/43)；95.3% (41/43) of the neuroendocrine neoplasm components were neuroendocrine carcinoma (NEC) and 4.7% (2/43) were neuroendocrine tumor (NET). Approximately 60.5% (26/43) neuroendocrine components had a Ki-67 index ≥ 55%. In addition, we further compared the prognosis of different subtypes of the MiNENs based on the neuroendocrine neoplasm component and non-neuroendocrine neoplasm component, and the results showed that there was no significant difference in survival between different subtypes of MiNENs (P > 0.05).

CONCLUSIONS

MiNENs can exhibit diverse clinicopathological characteristics, and there is no significant difference in prognosis among MiNENs subtypes, indicating that the definition of MiNENs can well summarize the prognosis of this type of tumor.

Anal canal mixed adenoneuroendocrine carcinoma in a young patient misdiagnosed as anal abscess

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are rare tumours of gastrointestinal tract, extremely rare in anal canal. We report a case of misdiagnosed MiNEN in a 38-year-old woman initially conservatively treated for a supposed anal fistula. In a second proctological evaluation, biopsy of the anal neoformation was performed and the histological specimen diagnosed a MiNEN. The complete staging showed a disseminate disease and the patient started a chemotherapy schedule. After 6 months, stable disease was revealed at the last imaging performed and radical surgery was offered to the patient that is actually on oncological follow-up without recurrence at 1 year.

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.

A Rare Collision Tumor: Adenocarcinoma in the Ampulla of Vater and Neuroendocrine Tumor in the Lower Part of the Common Bile Duct

In the biliary tree, only three cases of neuroendocrine tumor (NET) synchronous with adenocarcinoma have been reported so far. We experienced a case of NET, grade 2 (G2), of the common bile duct associated with adenocarcinoma of the ampulla of Vater (AoV). A Japanese man at his 60’s visited a local doctor, and obstructive jaundice was pointed out. Under the clinical diagnosis of carcinoma of the AoV, 20 x 20 mm, T3aN0M0 stage IIB, pylorus-preserving pancreaticoduodenectomy was performed. Dynamic computed tomography in an artery-dominant phase and microscopic examination revealed that the mass consisted of two different components; hypovascular, 2.5 cm-sized, exophytic adenocarcinoma in the AoV and hypervascular, 1.5 cm-sized, polypoid NET (G2) in the lower part of the common bile duct. The NET diffusely expressed neuroendocrine markers, including somatostatin receptor-2 (SSTR2), and adenocarcinoma cells arising from tubular adenoma focally expressed the neuroendocrine markers. Both malignancies were positive for caudal-type homeobox-2 (CDX2). It is presumed that NET occurred from intestinal-type adenoma/adenocarcinoma.

Mixed adenoneuroendocrine carcinoma of the colon, complex and unique clinical duality

In relation to the article "A case of a mixed adenoneuroendocrine tumor of colon" 1, we want to contribute a new case of this exceptional and biphasic clinical entity which are the MANECs (Mixed adenoneuroendocrine carcinoma), tumors represented by the mix of pathological components highly aggressive that affect the gastrointestinal and pancreatobiliary tract characterized by the dual presence of glandular and neuroendocrine epithelial elements, where each component represents at least 30% of the tumor.

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.

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

Clinicopathological features and prognostic factors associated with gastroenteropancreatic mixed neuroendocrine non-neuroendocrine neoplasms in Chinese patients

BACKGROUND

The incidence of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) is low. To improve our understanding of this rare tumor type and optimally guide clinical treatment, associated risk factors, clinical manifestations, and prognosis must be explored.

AIM

To identify risk factors that influence the prognosis of patients with gastroenteropancreatic MiNEN (GEP-MiNEN).

METHODS

We retrospectively analyzed the clinical data of 46 patients who were diagnosed with GEP-MiNEN at the First Affiliated Hospital of Bengbu Medical College (Anhui, China) between January 2013 and December 2017. Risk factors influencing the prognosis of the patients were assessed using Kaplan-Meier curves and cox regression models. We compared the results with 55 randomly selected patients with gastroenteropancreatic GEP neuroendocrine tumors, 47 with neuroendocrine carcinomas (NEC), and 58 with poorly differentiated adenocarcinoma.

RESULTS

Among the 46 patients with GEP-MiNEN, thirty-five had gastric tumors, nine had intestinal tumors (four in the small intestine and five in the colon and rectum), and two had pancreatic tumors. The median age of the patients was 66 (41-84) years, and the male-to-female ratio was 2.83. Thirty-three (71.7%) patients had clinical stage III and IV cancers. Distant metastasis occurred in 14 patients, of which 13 had metastasis to the liver. The follow-up period was 11-72 mo, and the median overall survival was 30 mo. Ki-67 index ≥ 50%, high proportion of NEC, lymph node involvement, distant metastasis, and higher clinical stage were independent risk factors affecting the prognosis of patients with GEP-MiNEN. The median overall survival was shorter for patients with NEC than for those with MiNEN (14 mo vs 30 mo, P = 0.001), but did not significantly differ from those with poorly differentiated adenocarcinoma and MiNEN (30 mo vs 18 mo, P = 0.453).

CONCLUSION

A poor prognosis is associated with rare, aggressive GEP-MiNEN. Ki-67 index, tumor composition, lymph node involvement, distant metastasis, and clinical stage are important factors for patient prognosis.

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.

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.