Headache as the only presentation of intravascular lymphoma.

Intravascular lymphoma (IVL) is a rare extranodal lymphoma, presenting with confusing clinical presentations and most cases have been diagnosed during the postmortem review. We report a case of IVL diagnosed by cerebrospinal fluid (CSF) examination and bone marrow biopsy in a patient with a daily headache from onset. In case of a daily headache from onset with normal neuroimagings, CSF examination may give any significant diagnostic clue and should be a consideration to exclude such causes as hematolymphoid malignancies, including the very rare IVL.