Double light-chain production by leukemic cells of common clonal origin: a case report with review of pertinent literature

We are reporting the first case of acute lymphoblastic leukemia whose individual leukemic cells produced both K and λ light chains, without any heavy chains, as demonstrated by double immunofluorescent staining. This case together with cases of lympho-plasmacytic neoplasia reported in the literature indicates that cells of a single clone are capable of producing more than a single class of light and/or heavy chains.