Long-term Seizure Disorder Caused by a Dermoid Cyst with Catastrophic Developments.

Glioblastoma multiforme (GBM) is a World Health Organization (WHO) grade IV primary malignant astrocytoma. Aneurysms are devastating intracranial neurovascular pathologies. Intracranial dermoid cysts are common, benign lesions which can be clinically silent or associated with seizure disorder. We describe physically adjacent diagnoses of dermoid cyst, intracranial aneurysm, and GBM in a single patient. Records were collected and reviewed to compile the final clinical picture. A 72-year-old male with a long history of seizure disorder, presented with new focal, unilateral neurological deficits. Radiographic evaluation including computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a dermoid cyst with an underlying developing GBM, which also, by happenstance, contained an aneurysm. During open surgical resection, multiple macroscopically distinct tissue types were noted. Histological analysis of tissue from each lesion confirmed the diagnoses including dermoid cyst, GBM, and aneurysm. Pathological analysis revealed the presence of extensive inflammatory cells throughout. Subsequent staining identified CD68 positive cells indicating a probable chronic inflammatory state. Chronic inflammation resulting from the presence of a long term dermoid cyst and ongoing seizures may have led to dystrophic changes in adjacent vasculature and approximating glial tissues, inducing the formation of an aneurysm and a secondary GBM. Therefore, while benign in nature, dermoid cysts can be related to seizure disorder and may cause chronic inflammation in surrounding brain tissue.