Abstract

A rare variant of glioblastoma characterized by giant or monster cells is now well recognized. However, this tumor had been remained in controversy on its pathogenesis, and the tumor had been considered to be a sarcoma until 1968, when the electronemicroscopic study demonstrated the presence of filaments mesuring 80 in diameter in the perikarya in giant cells as well as in smaller, better differentiated cells. The peroxidase antiperoxidase stain of glial fibrillary acid protein shows positive glial fibrillary fibers in their cytoplasm, accordingly the giant cells has been recognized as being of astrocytic origin. This concept has been redocumented by light microscopy since PTAH-positive astrocytic fibers are present in large numbers of neoplastic cells. The two cases reported here were frontal and occipital giant cell glioblastomas in 58 years old male and 44 years old women, respectively. On light microscopy, the tumor showed numberous characteristic giant or monster cells as well as the same features seen in the usual glioblastoma. The electron microscopy and special stains, PTAH and GFAP confirmed that the giant cells were in glial origin.

• Keywords: Glioblastoma;Giant cell Intracytoplasmic filaments measuring 80 in diameter;