Subependymal giant cell astrocytoma

Subependymal giant cell astrocytoma (SEGA), also known as subependymal giant cell tumor, is a slow-growing, low-grade (WHO grade I) brain tumor that arises from the walls of the lateral ventricles, typically near the foramen of Monro. SEGAs occur almost exclusively in the context of tuberous sclerosis complex (TSC), a genetic disorder caused by mutations in the TSC1 or TSC2 genes. These tumors are found in approximately 5–20% of individuals with TSC and are one of the major diagnostic criteria for the condition. Although histologically benign, SEGAs can cause significant morbidity due to their location: as they grow, they may obstruct cerebrospinal fluid flow through the foramen of Monro, leading to obstructive hydrocephalus. Key symptoms include signs of increased intracranial pressure such as headaches, nausea, vomiting, visual disturbances, and changes in behavior or cognitive function. In some cases, new-onset seizures or worsening of pre-existing seizures (common in TSC) may occur. Acute hydrocephalus can be life-threatening if not promptly treated. SEGAs are typically detected during routine neuroimaging surveillance recommended for individuals with TSC, often before symptoms develop. Treatment options include surgical resection, which can be curative when complete removal is achieved, and pharmacological therapy with mTOR inhibitors such as everolimus. Everolimus has been approved specifically for the treatment of SEGAs associated with TSC that cannot be surgically resected, and has demonstrated the ability to reduce tumor volume significantly. Regular MRI surveillance is recommended for all TSC patients, particularly during childhood and adolescence when these tumors are most likely to grow. The prognosis is generally favorable with appropriate monitoring and timely intervention.

Common questions about Subependymal giant cell astrocytoma