Xanthochromic cysts associated with meningioma.

Three cases of cystic meningioma encountered in one year are presented. It appears from a review of the literature, and an analysis of these three cases, that large xanthochromic cerebral cysts may be associated with meningiomas in any of three configurations: (1) centrally within the tumour; (2) peripherally within the tumour; (3) in the adjacent brain. Regardless of which configuration applies, the CAT scan appearance of such cystic meningiomas may mimic that of a glial tumour with cystic or necrotic change, and lead to an incorrect presumptive diagnosis. This false impression may be perpetuated by the gross appearance at operation, which can also mimic malignant glioma. Although several radiological features should suggest the possible presence of a cystic meningioma, we know of no definite radiological means of differentiating this lesion from the more common malignant glioma. This finding should underline the need to biopsy all suspected cerebral neoplasms, regardless of how much their appearance on CAT scan may suggest malignant glioma.