Recurrent encephaloclastic cyst induced by intraventricular topotecan

Objective To report two rare cases of encephaloclastic cyst induced by intraventricular topotecan. To share our experience in diagnosing and treating this rare disease. Background Ommaya reservoirs provide fast access and reliable drug delivery to cerebral spinal fluid. They are routinely utilized for the administration of intrathecal chemotherapy accounting for greater than 80% of cases for which they are used. Complications of Ommaya reservoir placement and its use consist of infectious and other late noninfectious causes. Encephaloclastic cysts provoked by intraventricular chemotherapy are very uncommon. The pathogenesis may result from alterations in CSF pulsations with retrograde flow of intraventricular chemotherapy into the brain parenchyma and subsequent development of a local chemical encephalopathy. It has been previously reported with methotrexate use but never with topotecan administration. Methods We report two rare cases of encephaloclastic cyst with intraventricular topotecan use. The patients were diagnosed and treated at The University of Texas MD Anderson Cancer Center. They consented to the publication of their laboratory results and imaging studies for educational purposes. Result The patients presented with metastatic cancers (breast/lung) complicated by leptomeningeal disease. Ommaya reservoirs were placed in both cases and patients were initiated on intraventricular topotecan at 0.4 mg twice weekly. After approximately 12 intraventricular treatments, both patients developed confusion, seizures and headaches. MRI of the brain demonstrated cystic dilatation of the brain parenchyma around the catheter that connects to the reservoir dome and delivers the drug to the intraventricular space. The catheter was surrounded by vasogenic edema. Catheters were removed and analyzed and were found to be intact. CSF analyses showed no evidence of infection or malignancy. Intraventricular topotecan was discontinued and both patients demonstrated sustained clinical and radiological responses. Conclusion These cases highlight an atypical complication of intraventricular use of topotecan with successful management.