An unsual vascular tumor of the Sylvian fissure
A 2-year old previously healthy female patient presented after having seizures for the previous 6 days. Her seizures occurred during the night and the early morning hours. Semiology is stereotyped and as follows: she wakes up from sleep, sits up, eyes roll up and she stares. The duration of each seizure is between 30-40 sec. The frequency varies from one to two seizures per night to about 4-5 per night.
The patient was started on Keppra and then Dilantin was added as her seizures persisted and were not controlled.
The child was born by normal delivery at term. Development has been normal.
Apart from the seizures, the child is asymptomatic.
General and neurological examination was normal.
An MRI scan was done. The most relevant pictures are included below. In summary, there is an avidly enhancing mass in the depth of right Sylvian fissure. The mass encases the Right MCA and its branches. ADC map shows increased diffusivity in the tumor.
A digital catheter angiogram was done and the pertinent images are shown below. In summary, the Right ICA study showed a tumor blush with no obvious discrete feeders to tumor. There were no obvious feeders of the tumor that could be addressed endovascularly. There were early tumor draining veins to the superior sagittal sinus and posteriorly toward the transverse sinus.
Management to date:
She underwent a right frontal craniotomy and open biopsy of the tumor. The tumor was not attached to the dura, but presented in part on the surface. Large arterialized veins were running on the surface of the tumor and on the surface of the adjacent normal appearing brain. The tumour was grey and very firm, so firm that it could not be incised with a microscissors. Two small fragments of the tumour were excised for biopsy and with each biopsy there was arterial like bleeding from the depth of the biopsy specimen – at about 3 mm depth.
The pathology is of a very vascular tumour, with blood vessels surrounded by bland stroma. Immunohistochemical studies have ruled out meningioma, hemangioblastoma, hemangiopericytoma, angiofibroma and sarcoma. Thus far, the pathological diagnosis is a “benign vascular mass, not otherwise specified”. Further pathology opinions are being sought.
The child has remained stable and normal neurologically. Despite optimal levels of dilantin and Keppra, she continues to suffer occasional brief seizures that occur only at night or in the early morning hours from sleep.
Have you seen such a case and do you know what we are dealing with?
How would you manage the child now?
This case of the month was prepared by Paul Steinbok and Ahmad Bader of BC Children’s Hospital, Vancouver, Canada. Many thanks to them for another interesting case.