CASE HISTORY

The patient had a mass on the back of his head for a year or more, causing no trouble until the onset of numbness, clumsiness and weakness of the right arm and leg three months before admission, and difficulty in finding words and memory defect for a somewhat shorter time. Examination: A huge mass was present in the left parieto-occipital region above the ear, laterally, towards the midline, medially, above the occiput behind and about midway between occiput and nason in front. It was soft in the middle but became harder peripherally and merged into the bone of the skull at the edges. The scalp was very vascualar with some large draining veins. The right arm and leg were slightly weak and all forms of sensation were diminished. There were signs of pariental cortical involvement such as neglect with flaccidity of the right side, tactile inattention and finger agnosia. The right knee jerk was brisker than the left. The abdominal reflexes were absent on the left, there was right ankle clonus, but the planter responses were both flexor. There was some dysphasia and considerable mental dulling. Investigation: X-rays of skull. Mottling in left parieto-occipital region and slight elevation of periosteum with suggestion of sunray effect. Pineal shift to the right and depression of the left choroidal plexus. Left carotid angiogram. Simultaneous filling of internal and external carotids. Branches of superficial temporal and occipital arteries supplied tumour. Displacement of posterior branches of anterior cerebral artery. Right Carotid Angiogram: Slight displacement anterior cerebral to the right. Extensive venous drainage of tumour. Aspiration Biopsy: suggested meningioma. LP elsewhere. CSF protein 100mg. Treatment: The left external carotid was ligated and at a subsequent operation, the tumour was removed with surrounding Calvarium 120mm in diameter. An irregular mass of tumour 100mm in diameter lay on the inner aspect of the Calvaria. Microscopy confirmed diagnosis of meningioma. The dural defect was repaired with nylon film. Progress: The day after operation the patient was a changed man. His personality became that of a charming and cheerful elderly man, well orientated and in every way normal mentally. The power in the right side returned except for some weakness of dorsiflexion of the foot and there had been no further evidence of dysphasia. Writing is still shaky, but much improved. His convalescence was rather long because of CSF leaking through the nylon sheath and requiring aspiration. He wears a plastic skull cap to cover the rather large skull defect. At follow-up 6 months later his general condition was excellent and his sight had improved sufficiently for him to discard spectacles.

PATHOLOGY

The surgical specimen comprises two parts, the intracranial tumour and the skull cap. The latter has been bisected and about half mounted. The dural portion of the tumour has been merely trimmed. The intracranial portion of the tumour comprises of a flattened nodulating mass 8x8x2cms. On the outer aspect (back of specimen) this has grown through the dura and its ragged surface can be seen. In life this was continuous with a thin sheet of tumour a few mm thick beneath the calvarium. At the level of section the latter is still visible but at a number of points finger like projections of tumour can be seen growing through it. On the upper surface the tumour, having erupted into the bone at many points, has formed a second thicker sheet of growth though this has not invaded through the periosteum, the latter forming a smooth clear capsule over it. The tumour itself is whitish though in parts it has been discoloured by pigment resulting from old haemorrhage. It does not show any particular structural pattern as some meningioma do. This is an unusual though well recognised behaviour in meningiomata and does not imply malignancy.