Complex chromosomal rearrangements in an unusual variant of hairy cell leukemia.

An unusual case of variant HCL with multiple ribosomal lamellar complexes and complex chromosomal changes is described. The karyotype of the main cell clone is characterized by involvement of chromosome 5 at q13.3 and interstitial deletion of 7q. However, there is no other evidence of myelodysplasia and the abnormal cells are of lymphoid origin with a B-cell immunophenotype. The clonal chromosomal evolution involves rearrangements at sites known to be specifically altered in lymphoid tumors.