Subependymal Giant Cell Astrocytoma

General characteristics

Giant cell astrocytoma is a benign, slow-growing mass lesion typically arising in the wall of the lateral ventricles, close to the foramina of Monroe and composed of large ganglioid astrocytes. [1]


SEGA occurs almost exclusively in patients with tuberous sclerosis complex (TSC); its incidence ranges from approximately 6–16% of patients with TSC. SEGA typically occurs during the first two decades of life. [1]


On imaging, the lesion has a classic astrocytic appearance with common calcifications. On MRI, it can be identified by its typical location and the classical findings of tuberous sclerosis. The lesion is normally hyperintense on T2 with heterogeneous signal if calcification is present. The hypo- to isointense lesion presents on T1-weighted imaging with a moderate enhancement. [1]


  1. M.F. Reiser, W. Semmler, H. Hricak (Eds.) "Magnetic Resonance Tomography", Springer 2008