Pleomorphic xanthoastrocytoma: some new observations.

Fourteen cases of pleomorphic xanthoastrocytoma (PXA) occurring in Japan were investigated to evaluate its various pathological features. The patients were generally young (average: 19 years), the tumor was superficially located and CT revealed well circumscribed contrast enhancing mass which was often accompanied by a cyst. Histopathological study revealed that the PXA is a pleomorphic and frequently desmoplastic astrocytic tumor characterized by chronic degenerative changes including lipidization of tumor cells. The desmoplasia was assumed to secondary proliferation of meningeal fibroblasts. Although the general consensus is that pial astrocytes are the most likely origin of PXA, "ordinary" astrocytoma may well develop into PXA by invading overlying meninges and inducing desmoplasia.