Importance of central nervous system involvement by neoplastic cells in a patient with Waldenström's macroglobulinemia developing neurologic abnormalities.

The clinicopathology of central nervous system (CNS) involvement with tumor formation in the brain of a patient with Waldenström's macroglobulinemia (WM) who developed neurologic abnormalities in the absence of blood hyperviscosity is reported. Extravascular infiltration by monoclonal lymphoplasmacytoid cells with considerable perivascular disruption of the brain and reactive gliosis was a conspicuous histopathologic picture. The tumor as well as the patient's neurologic symptoms were successfully controlled by local radiation to the brain. This case report illustrates the importance of CNS involvement by neoplastic cells in the differential diagnosis of a patient with WM developing neurologic abnormalities.