The regional distribution of these tumours may be estimated by reference to the following table[39]:—
| Cerebellum | 33 | cases. |
| Deep or subcortical | 32 | „ |
| Precentral | 30 | „ |
| Post-central | 25 | „ |
| Extra-cerebellar | 19 | „ |
| Pontine | 15 | „ |
| Temporo-sphenoidal | 13 | „ |
| Multiple | 7 | „ |
| Fourth ventricle | 5 | „ |
| Third ventricle | 4 | „ |
| Pituitary | 2 | „ |
Schüster,[40] from an investigation of 1,000 cases, showed that cerebellar tumours are relatively more common than cerebral, the comparative size of the two regions being taken into account. An examination of Paton’s table shows that cerebellar and extra-cerebellar tumours together form rather more than 25 per cent. in 202 cases of brain-tumour formation.
Pathology.
Gliomata, sarcomata, and endotheliomata are the three commonest types of tumour formation. Other forms are fibromata, tuberculomata, syphilomata, cysts, and carcinomata.
Fig. 62. A Glioma of the Brain.
Fig. 63. A Sarcoma of the Brain.