Meningioma in the Pineal Region

—Report of a Case and Review of the Literature—

Abstract

A case of meningioma in the pineal region is reported. The patient, a 40 year-old male, was referred because of a slight headache and the presence of a calcified lesion in plain skull X-rays. A neurological examination revealed a slight memory disturbance, minimum hemiparesis and a sensory disturbance on the left side. Plain X-rays and tomography of the skull showed large calcification 3 cm in diameter in the pineal region.
A 99mTc pertechnetate brain scan showed an area of increased activity in the same region. Angiography showed no tumor stain in any phase. In the venous phase, upward displacement of the vein of Galen and the straight sinus was demonstrated. Pneumoencephalography revealed that the size of the mass corresponded exactly to the size of the calcification. It was also demonstrated that the mass was free from the edge of the tentorium. Right parietooccipital craniotomy was performed and the tumor in the pineal region was removed subtotally. This tumor was considered to have originated from the velum interpositum. The postoperative course was uneventful. Preoperative symptoms and signs improved except for the left lower quadrant hemianopsia which was produced by surgical manipulation. The pathological diagnosis was meningothelial meningioma with psammoma bodies.
A review of the previously reported 35 cases can be summarized as follows. The origin of the meningiomas in the pineal region was either the velum interpositum (12 cases) or the junction of falx and tentorium (21 cases). This series of 36 cases including the present case consisted of 11 males, 21 females and four undescribed cases. In comparison with germinoma, characteristic clinical signs of meningioma in the pineal region were as follows.
1) The incidence of upward gaze palsy was much lower than that in germinoma cases.
2) Cerebellar signs, pyramidal signs and mental disturbances were found more commonly in meningioma cases than in germinoma cases.
3) Dysarthria and hypoglossal nerve palsy were seen only in meningioma cases.
In seven cases (22.6%), characteristic calcifications were demonstrated on plain skull films. However, tumor stains were found by angiography in only a few cases. The prognosis of this tumor was generally poor. Only four cases were reported to be cured without neurological defects by total removal. Improvements in preoperative symptoms were obtained in nine of the cases. The overall mortality was 60.6% and operative mortality was 27.3%. When removing meningioma in the pineal region, considerable attention must be paid to preventing damage in the deep cerebral veins and surrounding structures.