Fig. 1Preoperative magnetic resonance imaging scans. A 6.8×5 cm-sized solid and cystic intra-axial mass is present in the right temporooccipital area, compressing the posterior horn of the right lateral ventricle. (A) Transverse and (B) sagittal views.
Fig. 2Hematoxylin and eosin-stained squash slides for frozen diagnosis show a hypercellular smear (A) in a fibrillary background (C, sharp arrow). Multiple pleomorphic giant cells with hyperchromatic nuclei and eosinophilic cytoplasm are seen. Eosinophilic intranuclear inclusions are prominent (B-D, arrowheads). Perivascular pseudorosettes-like lesions are also noted (B, D, arrows).
Fig. 3Hematoxylin and eosin-stained permanent tissue sections show perivascular pseudorosettes and geographic necrosis (A), bizarre pleomorphic giant cells with prominent intranuclear eosinophilic inclusions (B, C) and mitosis (D).
Fig. 4Immunohistochemical staining reveals diffuse expression of glial fibrillary acidic protein (A) and dot-like expression of CD99 (B) and epithelial membrane antigen (C). The Ki-67 labeling index is about 10% (D).
Table 1A review of literatures about giant cell ependymomas including our casea
Table 2The cytologic features of previously reported giant cell ependymomas including the present case