Gastric mixed adenoneuroendocrine carcinoma: a clinicopathological analysis of 36 cases

Abstract

Objective: To investigate the clinicopathological characteristics of gastric mixed adenoneuroendocrine carcinoma (MANEC). Methods: The clinical and pathologic data of 36 cases of gastric MANEC collected from January 2011 to December 2018 in the Department of Pathology, Fujian Provincial Hospital were retrospectively analyzed. Light microscopy and EnVision immunohistochemical (IHC) staining were used in the study. The results were compared with 40 cases of gastric neuroendocrine carcinoma collected within the same period. Results: The 36 cases were collected, there were 29 males and 7 females. The patients' age ranged from 43 to 87 years (mean 66 years). The tumor diameter ranged from 1.0 to 9.0 cm (mean 5.0 cm). Clinical staging showed that four cases were at T1+T2 stages and 32 cases were at T3+T4 stages. The main clinical manifestations were upper abdominal pain, abdominal distension and dysphagia. Complete follow-up data were obtained in 20 (eleven living and nine dead) patients. Pathologic analysis showed that all tumors were composed of neuroendocrine carcinoma and adenocarcinoma and each of the components was more than 30%. IHC staining showed that CK was expressed in adenocarcinoma; whereas the neuroendocrine carcinoma mainly expressed CD56 and Syn. There was no significant difference in age, sex, T stage and prognosis between gastric MANEC and gastric neuroendocrine carcinoma(P>0.05). Gastric neuroendocrine carcinoma predominantly occurred in the esophagogastric junction and the gastric body but only rarely in the gastric antrum; gastric MANEC mainly occurred in the esophagogastric junction and the gastric antrum but rarely in the gastric body. Gastric MANEC was more prone to lymph node metastasis than gastric neuroendocrine cancer(P<0.05). Conclusions: Most of the gastric MANEC patients are middle-aged and elderly males, and the tumors predominantly occur in the esophagogastric junction and the gastric antrum. Most of the patients are found to have higher stages, and most of them have lymph node metastases and poor prognosis.