[Angioimmunoblastic T-cell lymphoma complicated with EBV-associated B-cell lymphoma].

A 71-year-old man with high fever and enlargement of the bilateral submandibular, cervical and inguinal lymph nodes was hospitalized at Hiroshima University Hospital. The immunohistochemical and pathologic findings from the biopsy specimens led to the diagnosis of angioimmunoblastic T-cell lymphoma (AILT) with a cluster of CD20-positive cells. Flow cytometry analysis by two-color staining did not reveal any neoplastic B cells. Southern blot analysis showed rearrangement of both the IgH gene and the TCR gene. Furthermore, PCR of the IgH gene using DNA extracted from purified CD19-positive cells from the lymph nodes showed a monoclonal band, and it was different from that of purified CD138-positive cells from the bone marrow. Furthermore, monoclonal Epstein-Barr virus (EBV) infection was detected with PCR using the SL18 and SL19 primers of the LMP-1 gene. Numerous EBER-positive cells were detected diffusely in the lymph nodes. These findings indicated a diagnosis of angioimmunoblastic T-cell lymphoma complicated with EBV-associated B-cell lymphoma, and that immunodeficiency in AILT led to an expansion of EBV infected B-cells.