Pericatheter CSF Edema and Cyst Formation, a Rare Complication of Ommaya Catheters

Ommaya devices have been increasingly used to treat patients with brain tumor, lymphoma/leukemia, leptomeningeal metastasis, or meningitis. This case report focuses on a rare case of CSF edema and cyst formation around an appropriately positioned Ommaya catheter, which may mimic abscess formation. A companion case of pericatheter abscess is also presented, and distinguishing MR imaging features are discussed.