| Objective:Compared with classical gastric cancer,Epstein-Barr Virus-associated gastric carcinoma(EBVaGC)seems to have unique clinicopathological features,different gastric cancer mechanisms and relatively better prognosis than classical gastric cancer.Therefore,although EBVaGC accounts for only a relatively small proportion of total gastric cancer,it should be considered a unique subgroup of gastric cancer for research and analysis.Although EBER-ISH has been identified as the gold standard for the diagnosis of EBVaGC,its specific histopathological features remain unclear.Therefore,this study intends to compare the histopathological features of EBVaGC with classical gastric cancer,and provide a possible clue for the subsequent tumorigenesis mechanism.Methods:The tissue sections of patients with gastric cancer who underwent radical resection of the Cancer Hospital of Tianjin Medical University from January 2016 to December 2017 were collected.Two high-grade pathologists reviewed sections and made diagnosis of EBVaGC according to the criteria of gastric cancer and EBER-ISH(+);analysed the HE and immunohistochemical staining sections;and analysed the clinicopathological features,immunohistochemistry and in situ hybridization results;and then discussed these results with relevant references.Results:From January 2016 to December 2017,538 cases of radical resection of gastric cancer were performed in Tianjin Medical University Cancer Hospital.The screening criteria were in accordance with the diagnostic criteria of EBVaGC in 27 cases,accounting for 5.02%.Among them,24 males and 3 females;aged 43-76 years(57.48±8.33 years old).The main clinical symptoms of the patient were intermittent upper abdominal pain,occasional hematemesis,and melena.Of the 27 tumors,25 were located in the corpus,1 in the cardia,and 1 in the fundus.All patients underwent laparoscopic radical gastrectomy.All patients were followed up for 1-3 years.All 27 patients had no tumor survival.The tumor was located in 1 case of the cardia,1 case of the fundus,and 25 cases of the corpus.Among them,24 patients had single tumors and 3 patients had multiple tumors.Specimens were seen by the naked eye: 27 cases were ulcerated.The tumor has a long diameter of 2-8 cm.The cut surface is grayish red and grayish white,and the border of the advanced tumor is unclear and hard.Observed under the light microscope: a large number of lymphocytes infiltrated,showing a strip-like shape and a small nest.Tumor cells are medium-sized,round or irregular,with cytoplasmic bicolor,nucleus vacuolated,thick nuclear membrane,visible nucleoli,some visible mitotic figures,interstitial lymphocytes,plasma cells,rare fibrous tissue.EBER in situ hybridization showed positive nuclear in 27 cases,and the positive signal was evenly distributed in the nucleus of tumor cells,which was not expressed in surrounding non-tumor cells.Immunohistochemistry showed that all 27 cases were positive for CK8&18,CD3,CD4 and CD8.Conclusion:EBVaGC is a unique subgroup of gastric cancer,accounting for approximately10% of all gastric cancer cases worldwide.This study observed that EBVaGC showed some unique clinical pathological features,including male superiority,advanced age susceptibility,proximal gastric susceptibility,ulcer type,and a large number of lymphocyte infiltration in HE stained sections,with CD3,CD4 CD8 is characterized by high positive expression;and relatively good clinical outcome of EBVaGC.However,the exact role of EBV in the development of gastric cancer is still not fully understood.Further research is needed to confirm the interaction between EBV infection,environmental factors and the genetic background of EBVaGC. |
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