Inactive glioma
Takeuchi, K.; Hara, M.; Yokota, H.
No Shinkei Geka. Neurological Surgery 8(10): 911-919
1980
ISSN/ISBN: 0301-2603 PMID: 7442922 Document Number: 162687
Misinterpretation of CT scans in a case of right frontal malignant astrocytoma was reported. This 40 yr old man was 1st hospitalized because of reported generalized convulasive seizures of late-onset epilepsy. There was no abnormality in general and neurological examinations except vascular hypertension and mild retinal arteriosclerosis. A CT scan revealed a wedge-shaped nonenhancing low density area, with minimal mass effect in the right frontal region. EEG, Radionuclide brain scintigraphy and carotid arteriography revealed nothing peculiar. The right frontal lesion was temporarily diagnosed as cerebral infarct, combined with essential hypertension and the patient was discharged from the hospital. During follow-up, CT scan revealed a central contrast-enhancing area in the low density area of the right frontal lobe which was still showing minimal mass effect, .apprx. 13 mo. after the onset of the 1st epileptic seizure. Radionuclide scintigraphy revealed a clear hot uptake in the same region and carotid arteriography revealed a small tumor blush in the frontal pole. At that time there was no neurological abnormality, including symptom of increased intracranial pressure, and EEG was interpreted to be within normal limits. Right frontal exploration revealed an infiltrative tumor within the frontal lobe. The tumor was removed and vaporized subtotally by means of CO2 laser. Histological examinations of the tumor tissue revealed malignant astrocytoma. The importance of late-onset epilepsy as the 1st symptom of brain tumor in adult patients is emphasized. Careful examination and follow-up is mandatory. Difficulties in diagnosis of supratentorial gliomas by CT scan are mentioned. Occasionally, infarcts and gliomas may appear similar on the CT scan. The differentiation may be assisted by neurological and neuroradiological examinations, including analysis of patient's history, cerebral angiography, radionuclide scintigraphy, nuclear angiography, measurement of regional cerebral blood flow, Xe-enhanced CT scan and follow-up CT scans. The natural life history of gliomas is discussed from the viewpoint of early diagnosis of so-called inactive or silent glioma found by CT scan in the outpatient office. The policy of treatment of such inactive glioma should be carefully determined case by case.