2011 Volume 20 Issue 4 Pages 289-298
Introduction: The gliosarcoma (GS) is a rare variant of glioblastoma (GB) containing distinct gliomatous and sarcomatous components. While uncommon, gliosarcomas have been known to arise secondarily, following conventional adjuvant therapy of malignant gliomas. We report a clinicopathological study of three secondary GS (SGS) cases. Clinical findings: All three patients were women, with a mean age of 44.3 years. Two had previously been diagnosised with GB, and the third had anaplastic astrocytoma (AA). As initial treatment, all patients underwent resection, followed by radiation and chemotherapy. GS was diagnosed at the first recurrence in one patient, and at the second recurrence in the other two. The mean latency of SGS induction, calculated from the diagnosis of GB/AA to the appearance of SGS, was 13 months. The mean length of survival from the time of SGS diagnosis was 6.7 months. The mean overall survival from the initial GB/AA diagnosis was 19.7 months. Clinically, in the final stage, fibrosarcomatous components were seen to characteristically grow into the subgalea or protrude out of the scalp after several recurrences. Pathological findings: In the two cases diagnosed with SGS at the second recurrence, fibroblastic cells had previously been recognized around the vessels at the first recurrence. Both cases also later exhibited abundant glial fibrillary acidic protein (GFAP) in the glial areas, and reticulin and fibronectin. in the fibrosarcomatous area. In the one SGS case diagnosed at the 1st recurrence, tumor cells showed gliosarcoma composed of chondrosarcomatous elements. Conclusions: SGS is a rare clinical entity that occasionally occurs after conventional adjuvant therapy for malignant gliomas. While the scarcity of cases makes research into the pathogenetic mechanism of SGS very difficult, the strikingly poor survival rates of patients who have undergone combined therapy raise questions concerning the value of such therapeutic radiation. A larger number of patients would be valuable in helping to elucidate the role of radiotherapy, and patient response to treatment.
