Meningeal involvement in early stage chronic lymphocytic leukemia.

Two patients with early stage chronic lymphocytic leukemia were found to have meningeal involvement. The diagnosis was confirmed by cerebral spinal fluid cytology in the first patient and by flow cytometric analysis in the second patient. Both patients responded well to intrathecal chemotherapy and cranial irradiation. Central nervous system infiltration by tumor cells has rarely been described in chronic lymphocytic leukemia but must be considered in all patients regardless of stage who present with lethargy, dementia, or focal neurologic signs.