De Novo Formation of Cerebral Cavernous Malformation in a Patient with Intractable Epilepsy: Case Report and Review Mustafa Efkan Colpan, MD, Levent Uckardesler, MD, Zeki Sekerci, MD, Konstantin Slavin, MD From the Department of Neurosurgery, University of Illinois at Chicago College of Medicine, Chicago, IL (MEC, KS); Department of Neurosurgery, Yildirim Beyazit Education and Research Hospital, Ankara, Turkey (MEC, ZS); and Department of Neurology, Anadolu Saglik Vakfi Hospital, Gebze, Turkey (LU). Keywords: Cerebral cavernous malfor- mation, de novo formation, epilepsy, in- tractable, mesial temporal sclerosis Acceptance: Received July 16, 2008, and in revised form October 30, 2008. Accepted for publication December 15, 2008. Correspondence: Address correspon- dence to Mustafa Efkan Colpan, MD, Uni- versity of Illinois at Chicago, Department of Neurosurgery (MC799), 912 South Wood Street, Chicago, IL 60612. E-mail: colpan@iit.edu. Conflict of Interest: None. J Neuroimaging 2010;20:302-306. DOI: 10.1111/j.1552-6569.2009.00362.x ABSTRACT AIM The exact origin and process of development of cerebral cavernous malformations (CCMs) is currently unknown. In this article, the authors present de novo CCM formation in a patient with intractable epilepsy and discuss the pathogenesis of CCM in light of several current theories. CASE DESCRIPTION A 34-year-old man presented with a 10-year history of intractable seizures. His neuro- logical examination was normal, and the initial magnetic resonance imaging (MRI) was suggestive of right mesial temporal sclerosis (MTS). Follow-up MRI study showed develop- ment of CCM in the right frontal region. Subsequently, invasive monitoring revealed right temporal seizure source, prompting right temporal lobectomy that resulted in abolition of epilepsy. Histological diagnosis of CCM was confirmed after the lesion was removed in a separate surgery. The patient recovered to normal lifestyle without any complications. CONCLUSION This appears to be a first documented case of de novo CCM formation in the setting of intractable epilepsy with ipsilateral MTS. Since the possibility of lesion development cannot be ruled out based on clinical examination, updated imaging and thorough neu- rophysiological workup are needed for successful treatment of patients with intractable epilepsy. Introduction Cerebral cavernous malformations (CCMs) are benign vas- cular lesions consisting of ectatic endothelium-lined channels within a matrix of collagenous tissue. 1-6 Although prevalence of CCM in general population reaches .5%, its origin and process of development are unclear. Both genetic and ac- quired etiologies have been proposed. 1-10 Multiple CCMs with positive family history have been referred to as dynamic le- sions, and de novo appearances in these patients are well de- scribed. 2-4,6 In sporadic cases, de novo formation of CCMs has been reported in only seven cases. 1 Here we describe a pa- tient with intractable epilepsy, who was found to have a newly appeared CCM while undergoing a workup for his seizures, and discuss development of CCM based on current literature data. Case Description A 34-year-old man presented with 10-year history of intractable secondary generalized tonic-clonic seizures. His medical and family history was unremarkable. Neurological examination was normal. The seizures were considered intractable based on their persistence despite multiple combinations of anticon- vulsants in maximum therapeutic ranges. Magnetic resonance imaging (MRI) examination revealed right hippocampal volume reduction with left and right hip- pocampal volumes measuring 6.7 and 3.9 cm 3 , respectively. The right hippocampus volume was calculated to be 58% of the left hippocampus volume. Long-term surface-based video electroencephalogram (EEG) revealed secondary generalized seizure activity with the right temporal focus. In order to con- firm right temporal seizure activity and in preparation for the right temporal lobectomy, the patient was admitted for inva- sive EEG monitoring. His preoperative MRI revealed de novo appearance of the right frontal lesion measuring 1 cm in diame- ter, with a heterogeneous hyperintense center and hypointense rim (Figs 1 and 2). These radiographic findings were consistent with cavernoma. Cerebral angiography was negative for arteri- ovenous malformation or venous abnormalities. Review of the patient’s imaging showed no indication of any sign of CCM on two previous MRI studies. The patient had four to six contact subdural electrodes im- planted into the frontal and temporal regions followed by ta- pering the anticonvulsants while undergoing continuous video EEG monitoring. All three recorded seizure episodes indicat- ing right temporal seizure activity with secondary generaliza- tion (Fig 3). Based on this workup, a right temporal seizure focus amenable to surgical resection was identified, and a right anteromedial temporal lobectomy through pterional approach was performed uneventfully. The patient was discharged 2 days after the surgery; the pathological examination of surgical spec- imen confirmed hippocampal sclerosis with neuronal loss in 302 Copyright ◦ C 2009 by the American Society of Neuroimaging