Cytogenetic changes in two cases of subependymal giant-cell astrocytoma.

Cytogenetic analysis of subependymal giant-cell astrocytomas (SEGAs) from two patients presenting the clinical symptoms of tuberous sclerosis complex (TSC) revealed clonal chromosomal changes, resulting in the partial loss of chromosome 22q in both tumors. Immunohistochemically, tumors exhibited features of glial differentiation, while ultrastructural studies identified the characteristic paracrystalline inclusions within the tumor cells. To our knowledge, it is the first cytogenetic description of SEGAs associated with TSC.