Gliosarcoma with primitive neuroectodermal, osseous, cartilage and adipocyte differentiation: a case report.

We describe a rare case of gliosarcoma with primitive neuroectodermal, osseous, cartilage and adipocyte differentiation. A 57-year-old man experienced a month history of headache, nausea and vomiting. Worse yet, the headache has become more severe for the past 6 days. Magnetic resonance (MR) images disclosed a lesion with operative indications located in the right frontal lobe. Then the tumor was macroscopically totally removed. Histologically, the tumor showed two kinds of components. One kind of the tumor cells appeared typical astrocytic tumor cells with anaplastic appearance. The other kind of the tumor cells appeared sheets of small round hyperchromatic cells, which presented a kind of pancreatic neuroendocrine tumor (PNET)-like structure. These sheets of small round cells were surrounded by a large number of relative-sparse-spindle cells. Multiple separate distinct areas of adipose tissue, osteoid matrix laid down and cartilage tissue were also identified. Immunohistochemically, a portion of typical astrocytic tumor cells and some small round hyperchromatic cells showed GFAP positivity. Small round hyperchromatic cells were positive for S-100, Fli-1, Nestin, MAP-2 and Syn. A large amount of relative sparse spindle cells (sarcomatous areas) were positive for vimentin. In addition, reticulin staining demonstrated expression of reticular fibers in relative-sparse-spindle cells areas but not in the astrocytic tumor cells and small round hyperchromatic cells areas. Molecular cytogenetic analyses demonstrated PTEN allele loss and no evidence of amplification of EGFR in both the astrocytic tumor cells, PNET-like structure and sparse spindle cells areas. These data suggest that this tumor was a gliosarcoma with primitive neuroectodermal, osseous, cartilage and adipocyte differentiation. To our knowledge, this is a rare gliosarcoma , reporting our additional new case would add to the better understanding of this tumor.