Gliosarcoma developing from an irradiated ependymoma

Abstract

A 17-year-old girl was operated for a cystic mass located deep within the left parieto-occipital white matter. Histologically the tumor was an ependymoma with a vascular stroma. In spite of irradiation the tumor recurred locally twice, 1 and 2 years respectively after the original operation. The ependymoma portion of the tumor remained unchanged, but the stroma showed increased vascular hyperplasia at the time of the second operation and transformation into a fibrosarcoma in the third operative specimen. Proliferating cell markers (MIB-1) were positive only in the ependymoma cell nuclei in the first two specimens, but were also extensively present in the nuclei of the fibrosarcoma in the third specimen. In the latter, the fibrosarcoma portion greatly overwhelmed the residual ependymoma islands, but remained sharply delineated from them. This is the first observed case of a gliosarcoma originating from an ependymoma. The histological pattern of this mixed tumor clearly indicates that the source of the sarcomatous portions was the neoplastically transformed fibrovascular stroma of the original tumor, rather than "desmoplastic" alterations of the neoplastic ependymal cells themselves.

Gliosarcoma Arising in Oligodendroglial Tumors (“Oligosarcoma”)

“…With few exceptions, 1,3,9,18,21,24 the glial component of gliosarcomas is nearly always astrocytic in nature, that is, glioblastoma. 2,8,10,[13][14][15]19 Gliosarcomas in which the glial element is oligodendroglial in nature are very rare.…”

“…4,5 There are but few reports of gliosarcomas in which the glial element is oligodendroglial 1,9,21,24 or ependymal. 3,18 Most of the former were reported before the era of 1p/19q deletion testing, now the standard for optimal evaluation of oligodendroglial neoplasms given its impact on prognosis. 6 The present study presents the histopathologic and immunohistochemical features as well as the results of FISH analysis for 1p/19q deletion in a series of 7 cases of gliosarcomas arising in tumors with an oligodendroglial or oligoastrocytic component.…”

Gliosarcoma arising from an anaplastic ependymoma: a case report of a rare entity

“…5,7 Endothelial cells, histiocytes, fibroblasts, and vascular smooth muscle cells have all been considered potential cells of origin of the sarcomatous component in this model. However, the monoclonal origin of gliosarcomas has recently gained favor.…”

“…Indeed, to date only 1 such case has been well documented. 7 We now present the first reported gliosarcoma arising from an irradiated anaplastic ependymoma and only the second example of a gliosarcoma arising from an ependymal neoplasm in general.…”

Cell-density-dependent manifestation of partial characteristics for neuronal precursors in a newly established human gliosarcoma cell line

“…The majority of reported gliosarcomas were found in recurring GBM after surgical removal of primary tumor followed with radiation therapy (Rutka et al 1986;Han et al 2010). Based on the observation of vascular hyperplasia in GBM, sarcoma was considered to originate from GBM via aberrant mesenchymal differentiation (Biernat et al 1995;Kepes et al 1996;Schittenhelm et al 2007). However, it could not be confirmed by finding endothelial proliferation in sarcomatous areas (Grant et al 1989;Sreenan and Prayson 1997).…”