Subependymal giant cell astrocytoma in the absence of tuberous sclerosis: a case report and literature review

Introduction and Importance: Subependymal giant cell astrocytoma (SEGA) is a benign intraventricular tumor classically arising near the Foramen of Monro. SEGAs almost always present as a component of tuberous sclerosis complex (TSC), an autosomal dominant disorder characterized by lesions in multiple organs. Case Presentation: A 16-year-old male with no significant past medical history presented with headache and dizziness. Imaging revealed intraventricular mass within the left lateral ventricle; the post-contrast image showed a contrast-enhanced lesion suggestive of SEGA. Following resection, histopathological analysis identified the lesion as a SEGA. However, on further workup, the patient was found not to meet the clinical criteria of TSC, which exemplifies a rare case of SEGA in the absence of a TSC diagnosis. Clinical Discussion: Tuberous sclerosis Complex (TSC) is a neurocutaneous disorder with a classical triad of seizures, mental retardation, and hamartomas in multiple organs and tissues. SEGA without TSC does not have multiorgan problems and hence doesn’t need ancillary testing but despite having a good outlook still needs follow-up for interval growth or recurrence. However, overall prognosis of isolated SEGA is better than SEGA associated with TSC. Conclusion: SEGA is commonly found to be associated with TSC. Although it is challenging to diagnose isolated SEGA, hence it is essential for physicians to be aware of the possibility of SEGA in the absence of other characteristics of TSC, which has many implications for a patient’s clinical course. This case report adds to current knowledge regarding isolated SEGA.