Intravascular lymphomatosis of the brain: a diagnostic problem.

Intravascular lymphomatosis (of B- or T-cell origin) is a rare lymphoproliferative disorder characterised by neoplastic proliferation of lymphoid cells within the lumen of capillaries, small veins and arteries with no or minimal involvement of the parenchyma. Its predilection sites are the skin and the brain. We studied a 44-year-old man who presented with a 2 year history of unexplained LDH elevation followed by a neurological syndrome without systemic involvement. Brain biopsy showed an intravascular lymphoma of the B-cell lineage. This report illustrates the diagnostic challenge of this rare disorder with a grim prognosis.