Mixed adenoneuroendocrine carcinoma of gastrointestinal tract: Report of two cases

Mixed adenoneuroendocrine carcinoma(MANEC) is a rare tumor of the gastrointestinal tract that consists of a dual adenocarcinomatous and neuroendocrine differentiation, each component representing at least 30% of the tumor. To date, only seven cases have been reported in the cecum, and less than 40 in the stomach. Our first case was diagnosed in a 74-years-old female as a polypoid lesion of the cecum with direct invasion in the transverse colon, without lymph node metastases. The second case was diagnosed in the stomach of a 46-years-old male as a polypoid tumor of the antral region that invaded the pancreas and presented metastases in 22 regional lymph nodes. The metastatic tissue was represented by the glandular component. In both cases, the tumor consisted of a moderately-differentiated tubular adenocarcinoma(with mucinous component in Case 1) intermingled with neuroendocrine carcinoma. Ki67 index was lower than 20% in Case 1, respectively higher than 20% in Case 2. The neuroendocrine component was marked by synaptophysin and neuron specific enolase, being negative for Keratins 7/20. The neuroendocrine component represented 60% in Case 1, and 40% in Case 2, respectively. The glandular components were marked by carcinoembryonic antigen, maspin and keratin 20/7(Case 1/2). Both cases were proved to be microsatellite stable. Independently by the localization and tumor stage, MANECs appear to be highly malignant tumors, with high risk for distant metastases. The aggressiveness seems to depend on the endocrine component, independent of its proportion. The neuroendocrine component could be a dedifferentiated adenocarcinoma with a neuroendocrine phenotype.

Mixed adenoneuroendocrine carcinoma of the ampulla:Two case reports

Mixed adenoneuroendocrine carcinoma(MANEC)is a malignant tumor with adenocarcinoma and neuroendocrine components,with≥30%of each component required.MANEC of the ampulla is rare.To the best of our knowledge,only 15 cases of MANEC of the ampulla have been reported in the English-language literature.Here,we report two cases of MANEC of the ampulla in two womenaged 43 and 60 years,which was confirmed by histology after pancreaticoduodenectomy.These tumors contained neuroendocrine and adenocarcinoma components.The neuroendocrine components were positive for chromogranin A(Cg A),synaptophysin(Syn)and CD56 by immunostaining.The adenocarcinoma components were negative for Cg A,Syn and CD56.Both cases were T3N0M0(StageⅢA).They survived for 15 and 20 mo after surgery,respectively.A brief discussion about the histopathological features,clinical behavior and treatment of MANEC of ampulla,and review of the relevant literature are presented.

Goblet cell carcinoid of the appendix and mixed adenoneuroendocrine carcinoma: Report of three cases

Neuroendocrine neoplasms are the most common epithelial tumors among appendix tumors. Appendix tumors that are completely or partially composed of neuroendocrine cells are divided into two categories: Classic carcinoid tumors and goblet cell carcinoid tumors(GCCT). They are known to progress more aggressively than classic(neuro) endocrine tumors. In this study, three cases with acute appendicitis symptoms are presented, including their clinical and histopathological findings. Microscopic examination detected GCCT in two cases and mixed adenoneuroendocrine carcinoma in one case, in addition to acute appendicitis.

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE compo-nent 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.

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.

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.