Gliosarcoma with Complete Osteosarcomatous Differentiation and Extensive Calcification: Case Report

Abstract

Gliosarcoma is a rare malignant tumor, grade IV according to WHO. It presents malignant biphasic glial and sarcomatous components. Calcifications and ossification are uncommon findings in these tumors. We reported a rare case of gliosarcoma with extense osseous differentiation and dystrophic calcification. A 51- year-old man that presented intense headache, visual alterations, and with an observed temporal right lobe tumor. He was surgically operated and the histopathological diagnosis was a gliosarcoma with osseous and cartilaginous component. He received radiotherapy with a total dose of 66 grays (GY) in 30 fractions. He then was hospitalized again due to intense headache and pyramidal syndrome. He was surgically intervened and an enormous indurated tumor that showed only dystrophic calcifications, osseous spikes, extensive necrosis and ghost glial cells was observed. Few viable neoplastic cells were determined. This tumor showed loss of Glial acidic fibrillary protein (GFAP), and Vimentin, Ostecondrin, Osteoponin, Ki-67, and blood vessel immunoexpression. Now, it is known that the effect of radiotherapy has influence in the development of tumors (specially in gliomas), but regression with extensive osseous dystrophic calcification after therapy can rarely be observed. Some authors refer to these as “tumoral stones”. Extensive calcification could be a sign of a good prognosis as it facilitates extirpation during surgery, although a broaden study in this topic is necessary to affirm this sentence. This is a rare case of gliosarcoma with rapid involution of tumor and stone formation secondary to radiotherapy.