Immune pancytopenia associated with a leukemic B-cell tumor carrying t(14;18)(q32;q21) translocation

We report a 75-year-old man who was initially suggested to have acute leukemia. The hemoglobin level was 3.8 g/dL, white cell count was 7,700/µL with an absence of mature neutrophils and 69.0% leukemic cells, and platelet was 0.4 × 10(4)/µL. Coombs' antiglobulin test was positive. Leukemic cells were CD5(-), CD10(+), CD20(+), CD23(-), and IgG/λ(dim+). The bone marrow consisted of normal hematopoietic precursors, whereas fluorescence in situ hybridization detected the BCL2/IgH fusion gene. He was treated with rituximab-containing chemotherapy, resulting in the resolution of pancytopenia. The underlying disease was a leukemic B-cell tumor with t(14;18)(q32;q21), and the pancytopenia was mainly caused by autoimmune mechanisms.