[Immunohistochemical and ultrastructural studies of subependymal giant cell astrocytomas in children with tuberous sclerosis].

Ten cases of subependymal giant cell astrocytoma associated with sclerosis tuberosa were reevaluated in order to assess their phenotyping and biologic features. All tumours were multifocal, located within lateral ventricles, often overlying the head of the caudate nucleus or protruding into the third ventricle. The phenotype of SGCA disclosed a complex pattern: giant cells were GFAP positive, some of them were stained with antibodies against neurofilament and NSE. Ultrastructurally, the cells of SGCA contained frequent dense bodies, numerous intermediate filaments and microtubules. Biologically SGCA is not malignant, although its appearance may suggest otherwise. No patient had an apparent recurrence within 3-5 years of observation.