Abstract
Subependymal giant cell astrocytoma (SEGA) associated with tuberous sclerosis complex (TSC) occurs in 5-20% of TSC patients, with a subset developing hydrocephalus. We present a case of a 14-year-old male diagnosed with TSC in the neonatal period who developed SEGA and subsequent hydrocephalus. Despite reducing the tumor size with the mammalian target of rapamycin (mTOR) inhibitors, ventricular enlargement persisted, indicating that obstructive hydrocephalus due to the foramen of Monro blockage was not the sole mechanism. Elevated cerebrospinal fluid (CSF) protein levels suggested additional factors like impaired CSF outflow. This case underscores the need for comprehensive treatment strategies and further research to better understand and manage hydrocephalus in TSC patients with SEGA.