Filamin A–negative hyaline astrocytic inclusions in pediatric patients with intractable epilepsy: report of 2 cases

Abstract

Although rare, hyaline cytoplasmic inclusions isolated to astrocytes of the cerebral cortex have been identified in a spectrum of diseases ranging from intractable epilepsy in pediatric patients with only mild to moderate developmental delays to Aicardi syndrome. These inclusions classically stain positive for filamin A, giving rise to the term “filaminopathies.” The authors report on 2 pediatric patients with intractable epilepsy and developmental delay who uniquely displayed filamin A–negative hyaline astrocytic inclusions in resected brain tissues. Additionally, these inclusions stained positive for S100 and negative for glial fibrillary acidic protein, chromogranin, neurofilament, CD34, vimentin, periodic acid–Schiff (PAS), and Alcian blue. These are the first reported cases of filamin A–negative hyaline astrocytic inclusions, providing a novel variation on a previously reported entity and justification to further investigate the pathogenesis of these inclusions. The authors compare their findings with previously reported cases and review the literature on hyaline astrocytic inclusions in intractable pediatric epilepsy.