Cases Of Subependymal Giant Cell Astrocytoma Research Articles

Subependymal Giant Cell Astrocytoma without Clinically or Genetically Identifiable Tuberous Sclerosis Complex: A Case Report

Background: Subependymal giant cell astrocytoma (SEGA) is a World Health Organization grade I tumor most commonly located in the lateral ventricles near the foramen of Monro. They are primarily associated with tuberous sclerosis complex (TSC), an autosomal dominant inherited condition that leads to a variety of tumors throughout the body. TSC must be diagnosed via either genetic criteria or clinical criteria. Cases of SEGA in patients without both genetically or clinically identifiable TSC are scarce, with only two instances identified of those genetically screened in the literature. We describe what we believe is only the third such case, a 22-year-old patient with no other clinical or genetic indicators for tuberous sclerosis. Case Description: The patient is a 22-year-old Caucasian female who experienced progressive symptoms of headaches, tinnitus and visual obscuration. A magnetic resonance imaging study of the brain revealed a homogeneously enhancing mass in the right lateral ventricle with obstruction of the foramen of Monro. The patient underwent a right frontal craniotomy for transcortical-transventricular resection of the mass. Histologic examination of the tumor revealed a diagnosis of SEGA. Germline genetic tests for both TSC1 and TSC2 were negative, and no additional clinical features were present. The patient was thus not felt to meet the criteria for a diagnosis of TSC based on the absence of clinical features, family history, and negative genetic testing. Conclusion: Although a rare phenomenon, SEGA should remain on the differential diagnosis for patients with newly found periventricular tumors and absence of TSC clinical features.

Subependymal Giant Cell Astrocytoma Presenting with Tumoral Bleeding: A Case Report.

We report a rare case of subependymal giant cell astrocytoma (SEGA) associated with tumoral bleeding in a pediatric patient without tuberous sclerosis complex (TSC). A 10-year-old girl presented with a 2-week history of an increasingly aggravating headache. Brain magnetic resonance imaging revealed an approximately 3.6-cm, well-defined, heterogeneously enhancing mass with multistage hemorrhages on the right-sided foramen of Monro. The tumor was completely resected using a transcallosal approach. Intraoperatively, the mass presented as a gray-colored firm tumor associated with acute and subacute hemorrhages. The origin of the mass was identified as the ventricular septum adjacent to the foramen of Monro. A pathological analysis revealed pleomorphic multinucleated eosinophilic tumor cells with abundant cytoplasm. These cells showed positive staining for the glial fibrillary acidic protein and S100 protein. A diagnosis of SEGA was established. The patient recovered without any neurological symptoms. There was no evidence of TSC. The radiological follow-up showed no recurrence for 2 years. This was a case of SEGA with intratumoral hemorrhage, for which a favorable outcome was achieved, without any neurological deficit after tumoral resection.

SG-02 * ROLE OF mTOR SIGNALLING PATHWAY IN THE PATHOGENESIS OF SUBEPENDYMAL GIANT CELL ASTROCYTOMAS

BACKGROUND: Subependymal giant cell astrocytomas (SEGA) are slow-growing benign intraventricular tumors whose pathogenesis is debated. Recent studies have shown that TSC1 and TSC2 genes are linked to the mTOR cell signalling pathway. OBJECTIVE: We aimed to analyze TSC1 and TSC2 gene mutation, protein expression of hamartin and tuberin, and protein expression of mTOR signalling cascade in a series of SEGA to determine their role in pathogenesis. METHODS: A total of 28 cases of SEGA were retrieved from archival material. Immunohistochemistry was performed on formalin fixed, paraffin-embedded tissue using antibodies against tuberin, hamartin, phospho-p70S6kinase, S6 ribosomal, phospho-S6 ribosomal, phospho-4E-BP1, Stat 3 and phospho-Stat 3. Mutation analysis of TSC1 (exons 15 and 17) and TSC2 (exons 33, 39 and 40) was done by DNA sequencing. RESULTS: Loss of immunoexpression of either hamartin or tuberin was found in 19 cases (68%). Pathogenic point mutations in selected exons of TSC1 and TSC2 genes were present in 5 out of the 20 cases studied. Robust expression of mTOR downstream signalling molecules phospho-p70S6 Kinase (100%), S6 ribosomal (82%), phospho-S6 ribosomal (64%), phospho-4E-BP1 (64%) and Stat3 (100%) was seen. Four cases (14%) showed immunopositivity for phospho-stat3. There was no significant correlation of immunoexpression of mTOR pathway proteins with immunoloss of tuberin and hamartin. CONCLUSION: There is a definite role for TSC1 and TSC2 genes in the pathogenesis of SEGAs as evidenced by loss of protein expression and presence of pathogenic mutations. Strong expression of mTOR downstream signalling proteins indicates activation of mTOR pathway in SEGA, indicating a role for this pathway in their pathogenesis. However, how mTOR activation is linked to loss of function of TSC genes needs further elucidation.

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 (WHOⅠ). It has distinctive clinical and histopathological features, and should be differentiated from gemistocytic astrocytoma, ependymoma, gangliocytoma and giant cell glioblastoma. doi: 10.3969/j.issn.1672-6731.2014.11.014

Subependymal giant-cell astrocytoma in children. An unusual discrepancy between histological and clinical features.

The authors describe five cases of subependymal giant-cell astrocytoma in children in which many clinical, histological, immunohistochemical, and ultrastructural features typical of this tumor were present. However, prominent focal necrosis and mitoses, features usually associated with high-grade tumors, were seen in all cases. Despite the presence of necrosis and mitoses, clinical follow-up studies have revealed a lack of aggressive tumor behavior after surgery alone. The discrepancy between the histological and clinical features in these cases is emphasized so that excessive treatment of a basically low-grade tumor may be avoided. Mast cells were seen in all five cases, often in large numbers.