1/20. Surgical treatment of posterior fossa tumors via the occipital transtentorial approach: evaluation of operative safety and results in 14 patients with anterosuperior cerebellar tumors.OBJECT: To determine the safety and usefulness of performing surgery via the occipital transtentorial approach to treat anterosuperior cerebellar tumors, evaluation of 14 patients was performed over a 5-year period. methods: The study was performed in 14 patients, aged 6 months to 71 years, who harbored anterosuperior cerebellar tumors of the posterior fossa including four hemangioblastomas, three cerebellar astrocytomas, three medulloblastomas, two metastatic tumors, one recurrent astrocytoma, and one rhabdoid cell tumor. All patients underwent surgical treatment by the same surgical team and via the same surgical approach. endoscopy combined with neuronavigation was used for large, deep-seated tumors extending to the fourth ventricle. Of the 14 patients, total or gross-total removal was achieved in 12 patients and subtotal removal in two patients. There was no incidence of mortality or morbidity in the 14 patients, and all functional outcomes were good to excellent postoperatively. Postoperative magnetic resonance imaging revealed that none of the patients had suffered brain damage or infarction around the cerebellum, brainstem, or occipital lobe. CONCLUSIONS: Although this study was the first in which a specific examination of the efficacy of the occipital transtentorial approach in patients with anterosuperior cerebellar tumors was undertaken, our findings suggest that this surgical approach is very useful, safe, and accurate for removing the primary tumor and evaluating the surrounding anatomy, as well as for determining operative strategy.- - - - - - - - - - ranking = 1keywords = rhabdoid (Clic here for more details about this article) |
2/20. Large cell/anaplastic medulloblastomas and medullomyoblastomas: clinicopathological and genetic features.OBJECT: medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution. methods: Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered. CONCLUSIONS: A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.- - - - - - - - - - ranking = 1keywords = rhabdoid (Clic here for more details about this article) |
3/20. Congenital disseminated malignant rhabdoid tumor and cerebellar tumor mimicking medulloblastoma in monozygotic twins: pathologic and molecular diagnosis.Malignant rhabdoid tumors are highly aggressive childhood tumors. Recently, all of the malignant rhabdoid tumors, whatever their location, have been related to the inactivation of the hSNF5/INI1 gene. A subset of cerebral tumors, associated with malignant rhabdoid tumors or isolated ones arising in siblings, showed similar molecular alterations. We report for the first time in monozygotic twins a congenital disseminated malignant rhabdoid tumor in one twin and a cerebellar tumor mimicking a medulloblastoma in the other. Molecular analysis revealed similar alterations for both tumors: a deletion of exon 7 of the hSNF5/INI1 gene in one allele, and a point mutation in the same exon in the other, suggesting a common genetic pathway. Analysis of constitutional dna revealed a germline mutation. These findings are in favor of a common etiology for rhabdoid tumor and a subset of brain tumors developing in infancy.- - - - - - - - - - ranking = 9keywords = rhabdoid (Clic here for more details about this article) |
4/20. Spinal subdural haematoma mimicking tethered cord after posterior fossa open surgery.We report the MRI findings in a girl aged 3 years and 10 months who developed a spinal subdural haematoma after posterior fossa open surgery for cerebellar malignant rhabdoid tumour. Emergency surgery was performed immediately because of increased intracranial pressure. Control MRI 48 h after surgery showed a spinal subdural haematoma without clinical signs of paresis or bladder dysfunction. Spinal subdural haematoma is rare, and only few cases have been reported, especially in children. This report suggests that "silent" (without clinical symptoms) postoperative spinal acute subdural haemorrhage can occur after posterior fossa surgery.- - - - - - - - - - ranking = 9.049131775719keywords = rhabdoid tumour, rhabdoid (Clic here for more details about this article) |
5/20. rhabdoid tumor of the kidney is a component of the rhabdoid predisposition syndrome.The rhabdoid predisposition syndrome (RPS) is characterized by pedigrees in which two or more individuals carry germline mutations of the hSNF5/INI1 tumor suppressor gene. The tumors associated with the syndrome include atypical teratoid/rhabdoid tumor (AT/RT), choroid plexus carcinoma, medulloblastoma, and extrarenal rhabdoid tumor. rhabdoid tumor of the kidney (RTK) has not been described as part of the RPS. We report a case of a 7-month-old boy with RTK whose sister had a malignant cerebellar tumor followed by a malignant lung and pleural tumor of childhood with typical rhabdoid histology. Molecular genetic analysis of the RTK and tissue from the pleural tumor revealed in both cases identical nonsense mutations of the hSNF5/INI1 gene on chromosome 22q11.2, where thymidine was substituted for cytosine in base 472. The proband had an identical germline mutation. This is the fifth genetically analyzed RPS pedigree and the first to include an RTK.- - - - - - - - - - ranking = 8keywords = rhabdoid (Clic here for more details about this article) |
6/20. Atypical teratoid/rhabdoid tumor of the cerebellum: report of two infantile cases.Atypical teratoid/rhabdoid tumor of the CNS is an aggressive infantile neoplasm of uncertain origin. In our two infantile cases, this tumor presented as a bulky cerebellar hemispheric mass with significant mass effect to the fourth ventricle and brain stem. Although the attenuation on CT and signal intensity characteristics at MR imaging of this tumor were similar to those of vermian medulloblastoma, cerebellar hemispheric location and aggressive growth pattern could be considered as different gross morphologic characteristics of this tumor. Despite intensive chemotherapy and radiation therapy, both of our two patients died within 8 months of pathologic diagnosis.- - - - - - - - - - ranking = 5keywords = rhabdoid (Clic here for more details about this article) |
7/20. Atypical teratoid/rhabdoid tumor: cytology and differential diagnosis in adults.Atypical teratoid/rhabdoid tumors (AT/RTs) are malignant intracranial neoplasms that usually occur in the posterior fossa of children. They are characterized by cells with paranuclear rhabdoid inclusions, a mesenchymal and epithelial immunohistochemical profile, and 22q deletions with inactivation of the INI1/hSNF5 gene. Although they usually occur in young children, AT/RTs are being recognized in adults with increasing frequency. We report the cytologic features of an AT/RT from the cerebellum of a 45-year-old man and discuss the differential diagnosis in adults.- - - - - - - - - - ranking = 6keywords = rhabdoid (Clic here for more details about this article) |
8/20. Atypical teratoid/rhabdoid tumour with leptomeningeal dissemination in an adult.A 22-year-old man presented with a rare case of atypical teratoid/rhabdoid tumour (AT/RT). magnetic resonance imaging showed a left cerebellar mass with leptomeningeal dissemination. Partial resection was performed. Histological examination revealed AT/RT. Postoperatively, whole neuraxis and local irradiation were performed. Three-drug chemotherapy with ifosfamide, cisplatin, and etoposide, and adjuvant intrathecal administration of methotrexate were repeated. Near complete response was achieved, and no tumour recurrence/progression has been noticed during the follow up of 24 months. Intensive radiochemotherapy can successfully control AT/RT, even with leptomeningeal dissemination.- - - - - - - - - - ranking = 45.245658878595keywords = rhabdoid tumour, rhabdoid (Clic here for more details about this article) |
9/20. Pediatric embryonal tumor of the cerebellum with rhabdoid cells and novel intracytoplasmic inclusions: distinction from atypical teratoid/rhabdoid tumor.We report a case of embryonal tumor with novel inclusion bodies occurring in the cerebellum of a 12-year-old girl. The tumor was histopathologically composed of small undifferentiated cells intermingled with a small number of rhabdoid cells, which had an ultrastructural feature of intermediate filament whorls. Immunohistochemically, the neoplasm showed a polyphenotype, including glial fibrillary acidic protein (GFAP), S-100, synaptophysin, chromogranin a, cytokeratin, vimentin, smooth muscle actin, and desmin. However, epithelial membrane antigen (EMA) immunoreactivity was absent. The MIB-1 labeling index was high (25.6%). Ultrastructurally, there was no evidence of neuronal or myogenic differentiation. The small neoplastic cells contained numerous small intracytoplasmic inclusions stained pink by eosin and red by Masson's trichrome stain. The inclusion body was a densely packed, granulovesicular structure at the electron microscopic level, and was immunoreactive for vimentin, GFAP, desmin, and actin. reverse transcription-PCR and immunohistochemistry showed the expression of INI1 at the rna and protein levels, respectively. In conclusion, this tumor was differentiated from atypical teratoid/rhabdoid tumor by the absence of EMA and the presence of INI1 mRNA and protein, and diagnosed as an unclassified, embryonal tumor. Eosinophilic, granulovesicular inclusions of the tumor cells are novel cytoplasmic inclusions in the brain tumor.- - - - - - - - - - ranking = 10keywords = rhabdoid (Clic here for more details about this article) |
10/20. Primary CNS malignant rhabdoid tumor (MRT): report of two cases and review of literature.Primary CNS rhabdoid tumor is an enigmatic and extremely rare malignant tumor of early childhood, probably embryonal, that has often been histopathologically classified together with rhabdoid tumor of kidneys or other organs in infants. Only four previously documented cases of primary CNS malignant rhabdoid tumor (MRT) were found in the literature. We report two cases of primary CNS MRT with biopsy and complete autopsy findings that share close clinicopathologic, immunohistochemical and ultrastructural similarities between the two. It is concluded that the primary CNS MRT is an entity which is extremely malignant, easily mistaken as a primitive neuroectodermal tumor, and potentially derives from a meningothelial precursor cell which is embryonally equal to the serosal mesothelial precursor cells which surround the kidneys and other organs. Hence, it tends to anatomically occur at the location of abundant meningeal infoldings such as the cerebellar cortex and may be diffuse or multicentric in its meningeal involvement. Furthermore, it may concurrently or multicentrically occur in association with MRT originating from the serosal membrane of other organs, such as the kidney.- - - - - - - - - - ranking = 7keywords = rhabdoid (Clic here for more details about this article) |
| | Next -> |