Primary gliosarcoma of the brain: radiologic and histopathologic features.

Gliosarcoma is a rare central nervous system (CNS) neoplasm with biphasic glial and non-glial malignant components. Here we describe the radiologic and histopathologic features observed in five cases of primary gliosarcoma. The mean age at diagnosis in the studied patients was 54.2 years; these patients were predominantly males (male:female ratio = 4:1). At diagnosis all patients had several clinical deterioration. The most common symptoms of presentation were: headache (5/5 cases), seizures (4/5 cases) and hemiparesis (1/5 cases). All the tumors were large (mean major diameter= 4.12±1.64 cm) at diagnosis as evidenced in computer tomography (CT) scans and magnetic resonance images (MRIs), with preferential involvement of the temporal lobe and frequent associated deviation of the midline structures. Other common characteristics identified on CT scans and MRIs were partial contrast medium uptake with annular pattern (5/5 cases), peripheral edema (5/5 cases), and central calcification (3/5 cases). In additional a peak of dye uptake was observed (4/5 cases) on MRI spectrometry. In the histopathology, the glial component showed malignant astrocytes, with high Ki67 (>60%) and p53 positivity; the sarcomatous components displayed pleomorphic spindle cells similarly with p53 positivity and high Ki67 (75-90%) in all cases. Dedifferentiation to pleomorphic sarcoma (two cases), fibrosarcoma (one case), leiomyosarcoma (one case) and MPNST (one case) were documented. All patients received radiotherapy/chemotherapy and had a median overall survival of ten months. The study of radiologic and histopathologic features in primary gliosarcomas of the brain is a priority to achieve early diagnosis that can be translated to better outcomes. Here we describe the radiologic and histopathologic features observed in a group of gliosarcoma patients with variable histopathologic dedifferentiation.