Fig. 3

Pathological findings on autopsy. a Macroscopic observation of the brain shows tumor tissue only close to the cysts without aggressive invasion of deep white matter. b Necrosis is clearly apparent in the tumor (black arrow). c Higher magnification of the tumor tissue showing it has well-defined boundaries (a, b, c). Pleomorphism of the tumor with giant cells is readily apparent (d). Clear xanthomatous cells with foamy cytoplasm are visible (black arrowheads) in the pleomorphic portion of the tumor (e), and the area is strongly positive on silver staining (f). The tumor is strongly positive for glial fibrillary acidic protein (g) and the Ki-67 index is extremely low as 1 % (h)