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

BACKGROUND Mixed neuroendocrine-nonneuroendocrine neoplasm(MiNEN)is a rare tumor that occurs in the gastrointestinal tract and pancreas,usually composed of adenocarcinoma and neuroendocrine carcinoma.MiNEN occurring in ampulla is even rarer.We report 4 cases of MiNEN in ampulla,combined with literature review to summarize the clinical features and treatment of the disease,in order to improve the understanding of the disease.CASE SUMMARY A retrospective analysis was performed in 4 cases of MiNEN of the ampulla diagnosed by pathology from 2014 to 2021.The 4 patients were all male,aged 67-81 years(average 72.25 years).Among them,2 patients had jaundice,1 patient had abdominal pain,and 1 patient had jaundice with abdominal pain as the first symptom.All 4 patients underwent enhanced CT or MRI,which all indicated that the tumors were located in the ampulla.Two patients underwent duodenoscopy,and a biopsy revealed ampullary adenocarcinoma.All 4 patients underwent radical pancreaticoduodenectomy.Four cases were followed up:One patient developed severe complications after the operation,his condition deteriorated,and he survived for 1 mo.In the other 3 patients,tumor recurrence was observed during follow-up,and 2 of them survived for 29 mo and 22 mo respectively.One case survived and is still being followed up.CONCLUSION MiNEN of the ampulla are extremely rare,lacking typical clinical symptoms and imaging features,and are usually diagnosed after postoperative histopathological and immunohistochemical examinations.The main treatment is radical surgical resection,which can be combined with chemotherapy.The best method of diagnosis and treatment needs further research.

Long-term survival of gastric mixed neuroendocrine-nonneuroendocrine neoplasm:Two case reports

BACKGROUND Gastric mixed neuroendocrine-non-neuroendocrine neoplasm(MiNEN),which consists of neuroendocrine and non-neuroendocrine components,is quite rare.Until now,most data on gastric MiNEN come from clinical cases,without largescale retrospective studies or controlled clinical trials.Consequently,no consensus regarding the origin,molecular characteristics,or appropriate treatment of MiNEN has been reached so far.We conducted chemotherapy of irinotecan plus cisplatin(IP regimen)and surgery in two patients with gastric MiNEN,which had never been used in treating this kind of tumor,leading to their long-term survival for more than 3 and 7 years,respectively.CASE SUMMARY We present two patients(one male and one female)with gastric MiNEN,with the primary manifestation of recurrent upper abdominal pain.After they were referred to our hospital,a diagnosis of gastric MiNEN was defined with the help of CT scan,and histopathological and immunohistochemical examinations on the samples of gastrointestinal endoscopy or radical surgery.The male patient(case 1)were found to have metastases in the reginal lymph nodes and the left liver.He received four cycles of IP regimens first,then the gastrectomy and partial left liver resection,followed by additional two cycles of IP chemotherapy.The female patient(case 2)underwent a laparoscopic gastrectomy,and received six cycles of IP regimen.She was found to have metastatic lesions in the right lung 2 years after that,and underwent video-assisted thoracoscopic surgery(VATS)of the lower lobe of the right lung.The two patients have now survived for more than 3 years and 7 years,respectively,without any evidence of recurrence or metastases.CONCLUSION IP regimen,combined with curative-intent surgery if feasible,could be considered as the priority in the choice of front-line chemotherapy for gastric MiNEN.