Background: Intravascular lymphoma is a proliferation of lymphoid cells, usually B cells, in small vessels, predominantly in the nervous system and skin.
Case report: We report a case of a man with a 3-year history of lymphopenia with no detectable etiology (all viral causes were ruled out) who developed intravascular lymphoma in the cerebral vessels.
Discussion: This case was particular as the patient had idiopathic CD4+ lymphopenia. It points out the probable role of immunodepression in the development of lymphomas, particularly in endovascular localizations.