부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.prp.2004.08.003 Byline: Yoon Kyung Jeon (a), Hee-Won Jung (b), Sung-Hye Park (a) Keywords: Ependymoma; Variant; Cerebellum; Giant cell tumor; Immunohistochemistry Abstract: We describe a giant cell ependymoma occurring in a 50-year-old man. The mass was located in the posterior aspect of the foramen magnum, extending from the cerebellar tonsil to the upper cervical spine. The tumor was a highly cellular neoplasm showing biphasic histology. Diffuse sheets of non-cohesive atypical giant cells, having eccentrically located single or multiple nuclei and plump eosinophilic cytoplasm, partly infiltrated the desmoplastic inflammatory stroma. Parts of perivascular pseudorosette-forming or pseudopapillary areas were composed of atypically elongated cells, which looked like conventional anaplastic ependymoma. There was a transitional area between two patterns. Numerous mitoses and focal necrosis were observed. Immunohistochemically, the tumor cells were immunoreactive for glial fibrillary acidic protein, vimentin, S-100 protein, and CD99. None of the tumor cells showed immunoreactivity for epithelial membrane antigen except for the intracytoplasmic lumen of a few vacuolated cells. Ultrastructurally, tumor cells were ependymal in nature; we noted cytoplasmic intermediate filaments and intercellular microrosettes with microvilli, cilia, and long zonula adherens. The features of this tumor, e.g. its superficial location, mixed giant cells, perivascular pseudorosettes or papillaries, complicated its differentiation from rhabdoid/papillary meningioma. However, immunohistochemistry and electron microscopy confirmed the diagnosis of ependymoma. The giant cell variant should be included in the subclassification of the ependymoma. Author Affiliation: (a) Department of Pathology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Republic of Korea (b) Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea Article History: Received 15 January 2004; Revised 10 August 2004; Accepted 10 August 2004