The Morphologic Features of Primary Epstein-Barr Virus Infection in the Gastrointestinal Tract An Approach to Correct Diagnosis

Epstein-Barr virus (EBV) is a herpes virus that has been shown to contribute to the development of multiple tumor types. There are isolated reports on EBV infection in the gastrointestinal tract, but, notably, there are none with detailed descriptions of the morphologic features. It is believed to be difficult to generalize the histologic features, as EBV does not cause viral inclusions in infected cells. This study was aimed at describing the pathologic changes of nonlymphomatous gastrointestinal EBV lymphoproliferative diseases in both immunocompetent and immunocompromised settings; the former was focused on chronic active EBV infection, and the latter was about the infection in posttransplantation patients. A retrospective search identified a total of 26 cases of EBV lymphoproliferative disease in the gastrointestinal tract-8 in immunocompetent patients and 18 in immunocompromised patients. We found that there was no difference in pathologic findings in immunocompetent and immunocompromised patients, which ranged from essentially subtle to severe mucosal architectural distortion with prominent lymphoid aggregates. Most cases showed either focal or diffuse lymphocytic infiltration comprised of small to intermediate-sized lymphocytes with a round shape and increased cytoplasm when compared with mature small lymphocytes. Focal lymphoepithelial lesions and karyorrhexis can be seen. Although gastrointestinal primary EBV lymphoproliferative diseases are not common, the mortality is high. Awareness of the potential histologic features combined with suspicion of EBV infection from clinical presentation, radiographic findings, and/or EBV serologies can aid in the diagnosis of primary EBV infection in the gastrointestinal tract.