Benign intracranial hypertension in chronic myeloid leukemia.

We present a patient with chronic myeloid leukemia (CML) who had marked bilateral disc swelling as part of his initial presentation. This occurred in the setting of raised intracranial pressure (ICP), with normal cerebrospinal fluid (CSF) composition and cell content, and normal neuroimaging. We discuss the possible mechanisms which could lead to disc swelling in CML and conclude that the raised ICP and subsequent papilloedema in our patient were the result of poor absorption of CSF into the dural venous sinuses. We propose that the very high white cell count (WCC) led to a hyperviscosity state which resulted in poor absorption of CSF and in so doing, created a clinical picture of benign intracranial hypertension (BIH).