Subependymal giant cell astrocytoma

Definition

A rare astrocytoma characterized by a benign, slowly growing lesion that typically arises in the walls of the lateral ventricles, and most commonly occurs in patients <&nbsp;20 years with tuberous sclerosis complex. Most patients present with worsening epilepsy or symptoms of increased intracranial pressure. This WHO grade 1 tumor is composed of astrocytes with various phenotypes (i.e. polygonal, gemistocytic, spindle, and ganglionic-like). On immunohistochemistry, it is usually positive for GFAP, S100, beta-tubulin, neurofilament, synaptophysin, NeuN, TTF1, and phosphorylated S6 but shows weak or negative staining for tuberin, hamartin, and Ki-67. It has its specific DNA methylation profile.