Pericallosal aneurysm simulating corpus callosum tumour.

The MRI characteristics of an isolated subacute aneurysmal corpus callosum hematoma, without evidence of blood in cerebrospinal fluid (CSF) spaces or ventricles, have not been previously reported. This report highlights the difficulty of accurate diagnosis and treatment in a patient with an unusual ruptured pericallosal aneurysm simulating a corpus callosum tumour. Additionally we analyse the particular radiological configuration and appearance of blood products in this region.