a 46-year - old man was transferred to our hospital for further evaluation and management of a gastric lesion that had been detected by gastroscopy during a medical checkup at a local clinic . the gastroscopy showed an approximately 2.5-cm sized submucosal mass with two active ulcers on the mucosal surface ( fig . the diagnostic impression of the referring physician in the local clinic was a gist or lymphoma . after a gastroscopic biopsy of the mucosal ulcer , the gastric lesion was diagnosed pathologically as an adenocarcinoma at this clinic . a contrast - enhanced ct of the abdomen using a 64-mdct scanner ( lightspeed vct , ge healthcare , milwaukee , wi ) was performed at our hospital . the ct images revealed a 1.5  2.5-cm ovoid mass with contrast enhancement at the lesser curvature wall of the gastric high body near the cardia ( fig . , the mass was initially thought to be a submucosal tumor such as a gist . there was no evidence of perigastric infiltration , enlarged lymph nodes , or distant metastasis on ct . after reviewing the clinical information of the biopsy - proven adenocarcinoma , a gastric carcinoma was included in the differential diagnosis on the radiological report . however , because the enhanced mass in the submucosal layer was not the usual ct finding for a gastric adenocarcinoma , comparison with the clinical findings of gastroscopy and pathology was recommended . the resected specimen appeared as a 2.0  2.5-cm submucosal mass with small elevated lesions and central ulcerations on the mucosa . on light microscopy , poorly differentiated adenocarcinoma with extensive lymphocytic reaction in the mucosa that invaded the submucosa and subsequently formed a submucosal mass was confirmed ( fig . the tumor invaded the subserosal adipose tissue , and was of the diffuse histological type ( lauren 's classification ) . the presence of ebv in gastric tumor cells was confirmed by performing ebv - encoded rna-1 ( eber-1 ) in situ hybridization . an etiologic association between ebv and gastric carcinoma has been demonstrated by the uniform expression of ebv in all carcinoma cells and its absence in normal epithelium or dysplastic lesions ( 1 , 2 ) . ebv - associated gastric carcinomas have an approximately 9% overall prevalence and , tend to be located in the cardia and body of the stomach when compared with conventional gastric adenocarcinoma ( 3 , 4 ) . these tumors are closely related to postsurgical gastric stump / remnant cancers ( 3 , 4 ) . in addition , approximately 15 - 25% of ebv - associated gastric carcinomas exhibit the lymphoepithelioma - like pattern , whereas 86 - 91% of lymphoepithelioma - like gastric carcinomas were ebv positive ( 3 , 4 ) . carcinomas with morphologic features similar to undifferentiated nasopharyngeal carcinomas are designated as lymphoepithelioma - like carcinomas and occur in the stomach , salivary gland , lung , and thymus . the pathologic findings indicate that the tumor cells , which are arranged in sheets or nests or as isolated cells , are surrounded by a dense population of non - neoplastic small lymphocytes ( 6 ) . ebv - associated gastric carcinomas can present as two histomorphological forms of a lymphoepithelioma - like carcinoma and a glandular adenocarcinoma , and these tumors are characteristically accompanied by prominent lymphocyte infiltration ; ebv has been thought of as being the main cause for the lymphocytic response ( 1 , 2 , 8 , 9 ) . the intramucosal lace pattern with lymphocyte infiltration has been reported to be the most characteristic morphologic feature of ebv - associated gastric carcinomas . in addition , carcinomas with submucosal invasion had a lymphoepithelioma - like pattern of the submucosa in 42% of cases ( 1 ) . the pathogenesis of the abundant lymphoid stroma in the submucosal layer remains unclear , but it is presumed that carcinomas with a lymphocytic reaction in the mucosa may invade the submucosa , and this lesion in the submucosa then grows due to the factors associated with lymphocytic induction , resulting in the formation of a submucosal mass ( 1 ) . lymphoepithelioma - like gastric carcinomas have a better prognosis than other forms of ebv - associated gastric carcinomas and conventional gastric carcinomas ( 1 , 2 , 9 , 10 ) . this is because the spread of tumors through the gastric wall and to the lymph nodes or remote organs may be prevented by the abundant lymphocytic reaction ; that is , the patient 's inflammatory response may contribute to a better prognosis in patients with ebv - associated gastric carcinoma ( 1 , 9 ) . despite its distinct clinicopathologic features , lymphoepithelioma - like gastric carcinomas are not familiar to most radiologists . in a ct study including 13 ebv - associated gastric carcinomas , authors concluded that the carcinomas were generally located in the upper gastric region , with a large thickness - to - width ratio , or with a bulky mass projecting from the wall ( 11 ) . however , the ebv - associated gastric carcinomas had various appearances on ct including focal mucosal thickening , marked wall thickening with contrast enhancement , and bulky mass formation . these appearances on imaging may overlap with cases of early gastric carcinoma , advanced gastric carcinoma , and lymphoma . in another study describing the endoscopic ultrasonographic findings of four ebv - associated early gastric carcinomas , hypoechoic submucosal nodules that corresponded to lymphoid stroma composed of carcinoma cells and infiltrating lymphocytes were observed in three cases that invaded the submucosa ( 7 ) . it is difficult to differentiate lymphoepithelioma - like gastric carcinoma presenting as a submucosal mass from other gastric submucosal tumors such as a gist , neurogenic tumor , and glomus tumor by imaging alone . however , as noted in the case reported here , a discrepancy between imaging findings suggestive of a submucosal tumor and the biopsy results of the adenocarcinoma may suggest the diagnosis present in this case . although mucosal ulceration can be present in both ebv - associated gastric carcinomas and submucosal tumors , the ulcerated shape of the advanced ebv - associated lesions has been thought to be related to the superficial depressed shape of the early lesions ( 12 ) . in conclusion , the mdct findings of an ebv - associated lymphoepithelioma - like carcinoma that developed in the gastric body presented as an enhancing submucosal mass with abundant lymphoid stroma admixed with adenocarcinoma . because the tumors have unique clinicopathologic features , understanding the imaging findings and clinical features of ebv - associated lymphoepithelioma - like carcinomas is important in the preoperative diagnosis and in differentiating this entity from other submucosal tumors .
a lymphoepithelioma - like carcinoma , characterized by a carcinoma with heavy lymphocyte infiltration , is one of the histological patterns observed in patients with epstein - barr virus ( ebv)-associated gastric carcinoma . 
 less than half of invasive carcinomas with lymphoepithelioma - like histology can grow to make a submucosal mass . 
 these tumors generally have a better prognosis than conventional adenocarcinomas . 
 we report a case of an ebv - associated lymphoepithelioma - like gastric carcinoma that presented as a submucosal mass on multi - detector ( md ) ct and correlate them with the pathology .