Subependymal giant cell astrocytoma: one case report and review of literature.

Background Subependymal giant cell astrocytoma (SEGA) is a rare kind of central nervous system tumor typically occurring in children or adolescents under the age of 20. The tumor commonly arises in the region of the foramen of Monro. Most SEGA patients present distinctive histopathological and immunohistochemical characteristics. Methods The clinical features, histopathological findings and immunohistochemical staining in one case of SEGA were analyzed, and the diagnosis and differential diagnosis of this disease with literature review were studied. Results A 13-year- old female patient presented dizziness, headache and vomiting. Cranial MRI examination showed abnormal signals in the left lateral ventricle near the foramen of Monro, and exhibited heterogeneous enhancement after contrast. Histologically, the tumor was composed of clustering of fibrillated spindle cells and giant cells with abundant cytoplasm, and they were mixed. Glassy hyaline cytoplasm and eccentric vesicular nuclei with prominent nucleoli were frequently seen in the giant tumor cells. Some of the giant cells appeared to resemble gemistocytic astrocytes or ganglion cells. Considerable nuclear pleomorphism and multinuclear cells were frequently seen. There was no significant microvascular proliferation or necrosis. Immunohistochemical findings showed diffuse and strong positivity in tumor cells for vimentin (Vim), and partial positivity for S-100 protein (S-100), epithelial membrane antigen (EMA) and glial fibrillary acidic protein (GFAP). A few giant tumor cells were positive for synaptophysin (Syn), but negative for neurofilament protein (NF), neuronal nuclei (NeuN) and cytokeratin (CK). Ki-67 labeling index was very low (< 1%). Conclusions SEGA is a benign central nervous system tumor (WHO I). It has distinctive clinical and histopathological features, and should be differentiated from gemistocytic astrocytoma, ependymoma, gangliocytoma and giant cell glioblastoma. [ABSTRACT FROM AUTHOR]