Dual surface immunoglobulin light-chain expression in B-cell malignant neoplasm is a rare event, and has been predominantly reported in chronic lymphocytic leukemia. Herein, we report a case of aggressive B-cell lymphoma with κ/λ-dual surface immunoglobulin light-chain expression of a 69-year-old woman. The lymphoma cells were positive for CD5, CD19, CD20, HLA-DR, Igκ and Igλ. Southern blot analysis confirmed rearranged bands for both light chains with a monoclonal heavy chain rearrangement. She was treated with a combination of rituximab and CHOP regimen, but died of the progressive disease. To our knowledge, this is the first case of aggressive B-cell lymphoma showing dual κ/λ expression; the possible mechanisms of abnormal light chain expression are discussed.
2007 by The Japanese Society of Internal Medicine