A case of Epstein–Barr virus‐associated lymphoepithelioma‐like carcinoma of the colon. Issue 6 (31st March 2021) - Kanno‐Okada, Hiromi
Abstract : Lymphoepithelioma‐like carcinoma is a poorly differentiated carcinoma with prominent lymphoid infiltration occurring in various organs but is exceedingly rare in the colorectal region. This malignancy is frequently associated with Epstein–Barr virus (EBV). Here we report a case of EBV‐associated lymphoepithelioma‐like carcinoma of the cecum in an 84‐year‐old male who presented with occult blood. In situ hybridization for EBV‐encoded small RNAs (EBER) in an endoscopic submucosal dissection specimen showed that the tumor consisted of EBER‐negative well‐differentiated tubular adenocarcinoma and EBER‐positive lymphoepithelioma‐like carcinoma. Real‐time PCR detected 7.16 copies of the EBV genome per cell in a sample microdissected from the latter component. Genotyping analysis demonstrated EBV genotype 1, and viral protein/transcript expression in the tumor showed EBV latency I. Expression of Ephrin receptor A2, a recently reported receptor for EBV, was demonstrated in the tumor cells by immunohistochemistry. To our knowledge, this is the first report of lymphoepithelioma‐like carcinoma in the colorectal region showing a definite association with EBV infection.