Secondary cutaneous infiltration in B cell chronic lymphocytic leukemia.

We describe a patient presenting with B cell chronic lymphocytic leukemia (B-CLL) who subsequently developed cutaneous infiltrates. Specimens of the blood, bone marrow and cutaneous infiltrations all showed the same heavy-chain gene rearrangement. Following failure of conventional chemotherapy, and in view of the similarity of the disease to cutaneous T cell lymphoma, interferon-alpha therapy was employed with satisfactory results. Introduction of this cytokine to the therapeutic modalities for secondary cutaneous B-CLL would hopefully change the poor outcome of this entity, or at least could produce a better quality of life. Loss of histidine decarboxylase activity in the infiltrating cells - in contrast to circulating lymphocytes - may be associated with the transformation of B-CLL to a more aggressive infiltrative form, offering a possible explanation for tissue invasiveness. The changing character of the disease raises the possibility of a second mutational event in the course of B-CLL.