Mesial temporal lobectomy for the treatment of intractable temporal lobe seizures may show dual pathologies for example hippocampal sclerosis (HCS) combined with a malformation. In a lobectomy specimen from a 40-year-old female with typical radiological and pathological features of HCS, an additional histopathological finding was the presence of hypertrophic pyramidal cells in the dentate hilus, in which cytoplasmic accumulations of phosphorylated neurofilament were demonstrated. Although these cells closely resembled dysplastic nerve cells of cortical dysplasia, we argue that the cytoskeletal abnormalities observed are a result of ongoing alterations to hippocampal circuitry in an evolving HCS.