Primary Gastric T-cell Lymphoma Associated with Human T-cell Leukemia Virus Type I shows ‘Lymphoepithelial Lesions’: Case report

We describe an unusual case of adult T-cell leukemia/lymphoma (ATL) appearing in a 44-year-old female without leukemic change and systemic lymphadenopathy, which originated from the gastric wall and partially involved the paragastric lymph nodes. No other intraabdominal or intrathoracic organs, such as the liver, spleen, kidneys, adrenals, lungs, or bone marrow, were involved at the time of surgery. The clinical stage of this case was evaluated as IIE according to the Ann Arbor classification. Lymphoma cells were CD3+, CD4+, CD8-, and CD79a-. Southern blot analysis revealed monoclonal integration of proviral DNA from human T-cell leukemia virus type I. Interestingly, the lymphoma cells formed ‘lymphoepithelial lesions’ which are usually observed in gastric mucosa-associated lymphoid tissue (MALT) B-cell lymphomas. A rare pattern involving ATL cells and the presence of lymphoepithelial lesions in this case indicated a diagnostic pitfall of gastric MALT lymphoma.