Meningeal tumors showing both benign and malignant portions are relatively uncommon. However, the case to be presented is more unusual in that it is an example of a malignant tumor apparently arising from the margin of a benign meningioma, the two growths being contiguous but not blended. In addition, this tumor had an uncommon site, since it was limited to the inferior surface of the cerebellum without involving any major dural sinuses. Localization was made possible through involvement of bone by the benign portion of the tumor before clinical findings were more than suggestive.
REPORT OF CASE
Irritability for four months, feeling of unsteadiness for three months and vague discomfort in the back of neck for one month. Unsustained horizontal nystagmus on looking to the right, slight unsteadiness for a few steps after rising suddenly and moderate suboccipital tenderness on the right side. Erosion of both tables of the skull
Bradford FK, Miller AJ. MENINGIOMA SHOWING SARCOMATOUS DEGENERATION. Arch NeurPsych. 1940;43(4):778-783. doi:10.1001/archneurpsyc.1940.02280040165010