Ependymosarcoma with eosinophilic granular cells

Ependymosarcoma is a new entity of malignant gliomas composed of ependymal and sarcomatous components. We report a rare case of ependymosarcoma with eosinophlic cells which occurred to the right trigon of the lateral ventricle. A 62‐year‐old man complained of headaches over a 2‐month period. A hard, gray mass was found in the right trigon of the lateral ventricle during the operation. Although he received radiation and chemotherapy, the patient died due to tumor disseminating through the whole brain within 7 months after the operation. The histological examination revealed that the anaplastic glial components intermingled with the sarcomatous components. Immunohistochemically, sarcomatous cells were positive for α smooth muscle actin and desmin. However, anaplastic glial cells were not positive for these markers. In addition, Masson trichrome stain showed a plethora of collagen fibers between sarcomatous cells, but no collagen fibers were produced by the glial tumor cells. Solid focal papillary lesions of the glial tumor showed dot‐like epithelial membrane antigen and diffuse cytoplasmic D2 ‐40 immunoreactivity. Based on the above findings, these anaplastic glial tumor cells should show focal ependymal differentiation, and sarcomatous cells show myofibroblastic differentiation. In addition, almost 10% of the tumor cells in the neoplasm showed bright eosinophilic granules in the cytoplasm. These cytoplasmic eosinophilic granules and bundles were negative on PAS staining. Intracytoplasmic eosinophilic granules of tumor cells were strongly positive for αB ‐crystallin, HSP 27 and GFAP , respectively. These findings suggest that the clinicopathological characteristics of the present case should be consistent with the criterion of ependymosarcoma by R odriguez et al .