Gliosarcoma in patients under 20 years of age. A clinicopathologic study of 11 cases and detailed review of the literature

Abstract

Background: Gliosarcoma is a rare variant of IDH- wild type glioblastoma with both glial and mesenchymal differentiation. It accounts for approximately 2% of glioblastomas and has a poor prognosis similar to that of classic glioblastoma. It is seen mostly between 40 and 60 years of age with a mean age over 50 years. Pediatric gliosarcoma is even rarer than gliosarcoma in adults. We describe the clinicopathological features of gliosarcoma in patients under 20 years of age and determine whether there are significant differences from gliosarcoma in adults. We also present detailed review of published literature on pediatric gliosarcoma.

Methods: Slides of gliosarcomas in patients under 20 years of age were reviewed. Clinicopathological features were noted in detail and follow up was obtained.

Results: Eleven cases of gliosarcoma were reported in patients under 20 years of age. Ages ranged from three to 19 years (mean age 13 years). Frontal, parietal and temporal lobes were the commonest locations. Mean and median tumor size was six and five cm respectively. All 11 cases demonstrated the classic biphasic pattern. In 10 cases, glial component was astrocytic and was highlighted on GFAP. Sarcomatous component in most cases resembled fibrosarcoma and was high grade in 72.7%. Glial areas were reticulin poor while sarcomatous areas were reticulin rich. In over 45% cases, bizarre tumor giant cells were seen in the sarcomatous areas. In 1 case, sarcomatous areas showed extensive bone and cartilage formation. Other histologic features included hyalinized blood vessels, hemorrhage, infarction, gemistocytic cells, rhabdoid cells etc. Follow up was available in nine patients, five received chemoradiation post resection while three received radiotherapy only. Prognosis was dismal and eight patients died within one to 14 months following resection.

Conclusions: Gliosarcomas in patients under 20 comprised 13% of all gliosarcomas reported during the study period. Frequency and mean age were higher compared to other published reports. Pathological features were similar to those described in literature. Clinicopathological features and prognosis of pediatric gliosarcomas were similar to adult gliosarcomas.

Keywords: Astrocytic; Biphasic; Cerebral hemispheres; Glial; Glioblastoma; Gliosarcoma; Mesenchymal; Pediatric.

Fig. 1

a T2WI Axial Image: A well-defined rounded T2WI heterogenous signal intensity mass seen in right parietal lobe with significant perilesional edema. b T2WI Sagittal Image: A well-defined rounded T2WI heterogenous signal intensity mass seen in right parietal lobe with significant perilesional edema c T1 Axial post-contrast: Avid post contrast enhancing mass with few central hypointensities identified in right posterior parietal lobe and surrounding perilesional edema. d T1 coronal post contrast image: Avid post contrast enhancing mass with few central hypointensities identified in right posterior parietal lobe and shows surrounding perilesional edema

Fig. 2

a Classic biphasic appearance of gliosarcoma. The mesenchymal elements at top are sharply demarcated from glial component at bottom. b Oligodendroglioma as glial component was seen in one case. c. GFAP expression in the glial component. d. Mesenchymal component appeared as fibrosarcoma in most cases

Fig. 3

a. Vimentin positivity in mesenchymal component. b While glial areas are reticulin poor, c, mesenchymal component was reticulin rich. d. Focal bizarre tumor cells in mesenchymal component

Fig. 4

a. Trabeculae of lamellar bone in mesenchymal component. b. Prominent large vessels were noted in some cases. c & d Sheets of gemistocytes and rhabdoid cells are focally seen in few cases