T-cell form of chronic lymphocytic leukaemia: A reaffirmation of its existence

Early in the 1980s three categories of T-cell chronic lymphocytic leukaemia were recognized: CD4(+) CD8(-) knobby type, CD4(-) CD8(+) azurophilic type and CD4(+) CD8(-) adult T-cell leukaemia (ATL) type. Both azurophilic and ATL types were later shown to be distinctive disorders, whereas the knobby type has been largely neglected and even considered non-existent by some authors. In this report we describe two patients with leukaemia of CD3(+) CD4(+) CD8(-) post-thymic T lymphocytes presenting with marked lymphocytosis, generalized lymphadenopathy and hepatosplenomegaly. We believe that CLL of post-thymic T-lymphocytes is a distinct entity, and merits a separate designation from other T-cell leukaemias.