An immunohistochemical finding in glioneuronal lesions associated with epilepsy: the appearance of nestin-positive, CD34-positive and tau-accumulating cells.

Several kinds of unusual cells have been pathologically identified in epileptic patients. CD34-positive, nestin-positive and tau-positive cells are some of them. However, no reports have investigated the significance of these cells. We examined 14 cases of seizure-associated glioneuronal lesions to investigate the incidences and distributions of these cells and the association between their incidence and clinical parameters. CD34-positive and nestin-positive cells were seen in 43% and 50% of cases, respectively. In the regions with structural anomalies, there were increased numbers of CD34-positive cells and nestin-positive cells, but they were identified as different cells. Both examinations showed many abnormal processes in oligodendroglial-like cells with round nuclei. In contrast, few reactive astrocytes that demonstrated immunoreactivity for glial fibrillary acidic protein were found in this area. Tau accumulation was present in 37% of cases. There was no correspondence with the regions showing increasing numbers of nestin or CD34-positive cells. There were no significant associations between epileptic clinical parameters and the incidences of the abovementioned immunopositive cells. CD34-positive cells and nestin-positive cells are found as frequently as balloon cells and are associated with abnormal reconstitution of the cortex. These findings support the assertion that increases in the numbers of these cells might contribute to promoting epilepsy. In addition, these immunopositive cells are valuable findings for the pathological identification of epileptogenic lesions.