Gastric lymphoepithelioma-like carcinoma associated with Epstein-Barr virus proved by in situ hybridization study: a case report.

Undifferentiated gastric carcinoma with prominent lymphoid infiltration and a striking resemblance to nasopharyngeal lymphoepithelioma has rarely been reported. Recently, the Epstein-Barr virus (EBV) genome has been demonstrated in some cases of gastric carcinoma with a morphology similar to undifferentiated nasopharyngeal carcinoma (NPC). One such case has been identified here by immunohistochemistry; it was explored for the EBV genome by RNA in situ hybridization (ISH) with an EBERs (Epstein-Barr virus encoded RNAs) probe. EBV RNAs were detected uniformly in the carcinoma cells or adjacent dysplasia epithelium, but were not present in the related lymphoid infiltration or in normal gastric mucosa. These findings add to the growing body of evidence suggesting the strong association of EBV with gastric lympho-epithelioma-like carcinoma (LELC), and also indicate that a latent EBV infection may play a role in undifferentiated epithelial cells.