We present a complication of Ommaya reservoir placement that has not been previously reported. The development and resolution of a cavum septi pellucidi after placement of an Ommaya reservoir for intrathecal chemotherapy is described. A 32-year-old male patient with stage IV Burkitt's lymphoma presented to our institution with a persistent frontal headache and was diagnosed with recurrent central nervous system disease. A right frontal Ommaya reservoir was placed using imaging ...