[Phenotypic and genotypic characterization of splenic infiltrates in hairy cell leukemia].

Cells of splenic infiltrates of five patients with hairy cell leukemia have been analyzed for the expression of immunoglobulin by immunohistochemistry and for rearrangement of T cell receptor and immunoglobulin genes by the Southern blot technique. In each case surface immunoglobulins were found with monoclonal expression of light chains. Concomitantly, heavy and light chain gene rearrangements were present. These results confirm the B cell nature of hairy cells.