 Gemistocytes are also found in some chronic diseases and within certain brain tumors, which suggests the presence of a long-lasting pathological reaction.In the context of cancer (gemistocytic astrocytomas), gemistocytes are known to dedifferentiate to a high grade (III or IV) glioma (i.e.glioblastoma multiforme) at a rapid pace, usually indicative of a poor prognosis.