Solitary subependymal giant cell astrocytoma: Case report and review of the literature.

Tuberous sclerosis complex (TSC) is a multisystem autosomal dominant hamartoma syndrome caused by mutations in TSC1 or TSC2 genes, leading to upregulation of cell growth signalling pathways. Subependymal giant cell astrocytomas (SEGAs) are seen almost exclusively in TSC patients. We report a 'solitary SEGA' in an adult patient, with confirmed deletion of the entire TSC2 gene on tumour tissue DNA, in the absence of detectable constitutional mutation or clinical manifestations of TSC. These rare cases may be secondary to somatic mosaicism and provide an opportunity to explore the genetic basis of the syndrome and its related tumours.