Glioneuronal hamartoma with unusual clinical manifestations in a case of pharmacoresistant temporal lobe epilepsy

Epilepsy is a common and serious chronic neurological disorder, with pharmacoresistance occurring in up to one third of cases of epilepsy. Temporal lobe is the most frequent site of epileptogenic lesions, and surgically resected specimens from patients with pharmacoresistant epilepsy reveal a broad spectrum of lesions, with hippocampal sclerosis as the most common pathology while glioneuronal hamartoma is a rare entity. We report a case of a 62 year-old woman with chronic pharmacoresistant epilepsy characterized by an unusual clinical picture of complex, partial and generalized tonic-clonic seizures with associated repetitive back and forth pelvic movements, not clinically typical for temporal lobe epilepsy. However, video EEG monitoring, MRI, and brain SPECT revealed a right temporal lobe epileptogenic focus. Temporal lobectomy was performed and revealed glioneuronal hamartoma in the white matter, characterized by the presence of immature oligodendroglial-like cells, dysmorphic/ dysplastic small neuronal cells, and hybrid cells with intermediate morphology in a hypomyelinated fibrillar background. No proliferative activity was present. Immunostain for CD34 highlighted intense bush-like ramifications of the cell processes in the dysplastic glioneuronal cells. The patient remained seizure free during the follow-up period of 32 months. Our case is noticeable for atypical clinical features of temporal lobe epilepsy, associated with the rare entity of glioneuronal hamartoma composed of an unusual immature cellular composition with CD34 positivity.