High grade glioma in a focal cortical dysplastic lesion

A 61-year-old woman presented in 1999 with a recent onset of left-sided focal clonic seizures with associated vague speech arrests. A computerised tomography (CT) scan revealed a hypoattenuated non-enhancing lesion within her right temporal lobe which was biopsied and the histopathological features were reported to be consistent with a hamartoma, reminiscent of tuberous sclerosis. Her seizures remained partially controlled with phenytoin and carbamazepine. She presented again 2 years later with an increase in the frequency of her seizures. A magnetic resonance scan of her brain demonstrated a homogenously enhancing mass lesion in her right temporo-parietal lobe. An initial lobectomy showed a hamartomatous lesion on histology but a subsequent sample obtained from a wide resection carried out when there was further worsening of her condition revealed a grade IV astrocytoma within a focal cortical dysplastic lesion. Our case highlights the importance of considering the possibility of a cortical dysplastic lesion harbouring a malignancy and the need for further research to explore the behaviour of these malformative lesions.