Subependymal Giant Cell Astrocytoma (SEGA) is a rare, slow-growing brain tumor that usually affects children and young adults. There are several synonyms for SEGA, including subependymal nodules, giant cell astrocytoma, and subependymal glioneuronal tumors. These synonyms refer to different aspects of the tumor, such as its location and the type of cells it contains. Other terms used to describe SEGA include tuberous sclerosis complex-associated astrocytoma, which is a subtype of SEGA that is associated with a genetic disorder, and hamartoma, which is a benign tumor made up of tissue normally found in the affected organ. Despite the many different names for this tumor, SEGA is a rare and serious condition that requires expert medical care.