Adult T-cell leukemia initially manifesting as facial diplegia

We report an unusual case of adult T-cell leukemia (ATL) initially manifesting as facial palsy due to ATL meningitis, which was caused by lymphoid cells in the cerebrospinal fluid (CSF) with a different phenotype from those in the blood. A DNA southern blot analysis of the blood cells confirmed the diagnosis of ATL. The aberrant cells in the CSF contained nuclei with simple indentations and responded well to the initial chemotherapy, while leukemic cells in the blood showed lobulated or convoluted nuclei and were resistant to treatment. Flow cytometry performed before treatment demonstrated that the majority of the cells in the CSF were CD3+CD4+CD8-CD25+, consistent with ATL, whereas they expressed the CD45R antigen, which the blood ATL cells did not. These differences in the subphenotype, cell morphology, and responsiveness to treatment among the ATL cells in blood and CSF suggest that a single clone or subclone with heterogeneous nature was not generated, before the final development of ATL.