The significance of paraproteinemia in hairy cell leukemia: case report and review of the literature.

A case of hairy cell leukemia and IgG paraproteinemia is described. Peripheral blood surface marker analysis, serum paraprotein levels and immunoperoxidase stains of bone marrow sections at diagnosis and after 7 months of interferon treatment suggested the existence of two unrelated pathological B cell clones: one composed of malignant hairy cells and the other secreting the paraprotein. Previously reported cases of hairy cell leukemia with paraproteins are reviewed and our patient's contribution to the understanding of this association is stressed.