Abstract
Introduction/Objective
Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) and Epstein-Barr virus (EBV) lymphoepithelioma gastric carcinoma, are two distinct gastric malignancies, with well-known clinicopathological characteristics. Synchronous or metachronous presentation of both entities in the same patient is extremely rare.
Methods/Case Report
We report a case of a 78-year-old woman, who presented with a 3 cm gastric body mass. Histologically, the biopsy showed H. pylori gastritis, with diffuse monotonous atypical lymphocytic cells and prominent lymphoepithelial lesions. CD20 immunostain was diffusely positive in these cells, supporting the diagnosis of MALT lymphoma. The patient was treated for H. pylorieradication, followed by Rituxan for resistant MALT lymphoma found in a surveillance biopsy. After being free of disease for one year, the patient developed a 2.0 cm, ulcerated lesion adjacent to the previous site. Biopsy of this lesion showed gastric mucosa with diffuse lymphoepithelial lesions, and atypical epithelial cells highlighted by pan-cytokeratin. The associated dense inflammatory infiltrate was comprised predominantly of CD3 T-lymphocytes. EBV was detected by in-situ hybridization (ISH) for EBV encoded RNA, and was positive in the epithelial cells, but negative in lymphocytes. These findings are consistent with EBV associated lymphoepithelioma carcinoma.
Results (if a Case Study enter NA)
NA
Conclusion
This case is presented due to its rarity, with only two cases reported previously, which invokes further research into the interaction between both infectious agents. Secondly, lymphoepithelial lesions are a common finding in both diseases, and in small biopsies, these entities can mask or mimic each other. EBV ISH and background B and T lymphocytes may be a clue and help in the diagnosis.