Gliosarcoma. A study of 13 tumors, including p53 and CD34 immunohistochemistry

Abstract

Objective: Gliosarcoma is a biphasic neoplasm composed of a glioblastoma multiforme admixed with a sarcomatous component that is presumed to arise from a malignant transformation of the hyperplastic vasculature elements. We studied 13 cases of gliosarcoma to describe the clinical and pathologic features of this tumor. In addition, immunohistochemical analysis using p53 and CD34 was performed in an attempt to examine the histogenesis of gliosarcomas.

Design and setting: A retrospective study of 13 patients with gliosarcoma from a tertiary care center.

Results: The 13 patients (7 women, 6 men) had a median age of 62 years (range, 33 to 79 years). All patients were initially treated with surgical excision followed by adjuvant radiation therapy, and two received adjuvant chemotherapy. Nine patients died of disease (median, 9 months; range, 1 to 17 months). Three patients were alive with evidence of residual tumor at most recent follow-up (median, 18 months; range, 6 to 41 months). A single patient was lost to follow-up. Histologically, all neoplasms consisted of an admixture of glioblastoma multiforme and sarcomatous elements. The sarcomatous component resembled fibrosarcoma in 12 cases and a malignant fibrous histiocytoma in one case. The sarcoma appeared to arise from hyperplastic vasculature in five tumors. CD34 staining in all five of these cases was negative. Immunostaining for p53 was observed in eight tumors (61.5%). p53 positivity was definitely present in both glial and sarcomatous components in all but three positive cases. The degree of staining was comparable between the two elements in five cases, present in only the glial component in two cases, and not able to be reliably assigned to one or the other component in one case.

Conclusion: Gliosarcoma is an aggressive-behaving neoplasm, as previously reported. The presence of p53-positive immunostaining, similar to glioblastoma multiforme, may be indicative of a role for the p53 gene in these neoplasms. A lack of CD34 staining does not support an endothelial cell origin for gliosarcoma.