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.