Utilidad de 11C-metionina PET/CT en neurooncología / Utility of 11C-methionine PET/CT in neuro-oncology

La tomografía por emisión de positrones con metionina carbono 11 (11C-metionina PET/TC) se utiliza en la evaluación de los tumores primarios del sistema nervioso central. Describimos nuestra experiencia sobre los primeros 4 pacientes con tumores de la serie glial estudiados con 11C-metionina PET/TC. Este es un estudio descriptivo, observacional y prospectivo. Se presentan 4 pacientes entre 38-50 años de edad con diagnóstico de gliomas (clasificación de la OMS). A todos se les realizó RM y 11C-metionina PET/TC para evaluar actividad tumoral y diferenciar progresión tumoral de pseudoprogresión. Caso 1, gliomatosis cerebri grado II posradioterapia. Caso 2, glioblastoma grado IV postratamiento RT + temozolomida. Caso 3, oligodendroglioma grado II posradioterapia en 1993. Caso 4, oligoastrocitoma anaplásico grado III postratamiento RT + temozolomida. El patrón de captación de la 11C-metionina comparativamente con la RM, demostró progresión tumoral en los casos 1, 3 y 4; en el caso 2 mostró captación aunque el diagnóstico final fue pseudoprogresión. A diferencia del PET con 18fluordeoxiglucosa, la captación de 11C-metionina en el tejido cerebral normal y en la pseudoprogresión es baja, y los gliomas se visualizan como áreas metabólicamente activas. En los casos presentados, el 11C-metionina PET/TC proveyó información valiosa sobre el comportamiento y extensión de la lesión, aunque en uno de los casos presentados no diferenció progresión tumoral de pseudoprogresión. El 11C-metionina PET/TC sería una herramienta útil en el estudio y seguimiento de los pacientes con gliomas.

Positron emission tomography (PET) with 11C-methionine (11C-methionine PET/CT) is a new technique used to evaluate primary central nervous system (CNS) tumors. We describe our experience regarding the first 4 patients with glial tumors and 11C-methionine PET/CT. This is a descriptive, observational and prospective study of 4 patients between 38-50 years of age, with different gliomas (WHO classification). MRI and 11C-methionine PET/CT were performed in all cases. Case 1, gliomatosis cerebri grade II post-radiotherapy. Case 2, oligodendroglioma grade II diagnosed and treated with radiotherapy in 1993. Case 3, glioblastoma grade IV post-radiotherapy + temozolomide. Case 4, anaplastic oligoastrocytoma grade III post-radiotherapy + temozolomide. The pattern of 11C-methionine uptake compared with MRI showed tumor progression in cases 1, 3 and 4, and in case 2 showed uptake although the final diagnosis was pseudoprogression. Unlike 18fluordeoxiglucose PET/TC, 11C-methionine uptake in normal brain tissue and pseudoprogression is low, and gliomas are displayed as metabolically active areas. The 11C-methionine PET/CT provided valuable information on the tumoral behavior and extension, although in one case presented did not differentiate tumor progression from pseudoprogression. 11C-methionine PET/CT could be a useful tool in the study and follow-up to patients with gliomas.

Pediatric gliosarcoma with fibrosarcomatous differentiation: Report of a rare case.

Gliosarcoma is a rare variant of glioblastoma with a biphasic pattern showing glial and mesenchymal differentiation. It is seen in adults during their fifth to sixth decades of life and is extremely rare in children. We report a case of primary gliosarcoma with fibrosarcomatous differentiation in an 11-year-old boy presenting with headache and vomiting. Imaging showed a contrast-enhancing isodense space-occupying lesion with areas of calcification in the right temporoparietal cortex. A total excision was done and, on histopathologic examination, a differential diagnostic consideration of gliosarcoma and teratoma with malignant transformation was made. After immunohistochemical analysis, a final diagnosis of gliosarcoma with fibrosarcomatous differentiation was then made. Primary gliosarcoma is a very rare tumor in children with a poor prognosis.

Gliosarcoma with prominent smooth muscle component (gliomyosarcoma): A report of 10 cases.

Background and Aim: Gliosarcoma (GS) is an uncommon malignant tumor of the brain, consisting of malignant glial, usually a glioblastoma (GB), as well as sarcomatous component; the latter is usually in the form of fibrosarcoma. We report a series of 10 GSs with prominent smooth muscle component, which is a rare occurrence. Settings and Design: Out of a series of 225 cases of GB admitted in our hospital, 10 were diagnosed as GS with prominent smooth muscle component, gliomyosarcoma (GMS). Materials and Methods: This is an observational study based on the experience with 225 cases of GB, encountered between 1995 and 2008, in our hospital. The tumors showing prominent spindle cell component were stained with reticulin and 20 with strongly positive reticulin stain were diagnosed as GS. They were further studied by immunohistochemical staining for glial fibrillary acidic protein (GFAP), smooth muscle actin (SMA), desmin and factor VIII antigen. Results: Out of 225 cases of GB, 20 were diagnosed as GS. Ten of these showed prominent smooth muscle component and were diagnosed as GMS. They revealed varying degrees of SMA and factor VIII Ag positivity. In the sarcomatous component, SMA and factor VIII positive cells were seen close to the vessel walls as well as away from them. Conclusion: GMS containing prominent smooth muscle component may not be as rare as has been reported in the literature. Both GS and GMS appear to arise from the vessel wall at least in some cases, suggesting their possible vascular origin.

Cerebral gliosarcoma: clinico-pathologic study of 8 cases

Gliosarcomas are biphasic neoplasms composed of a glioblastoma admixed to a sarcomatous component with different lines of differentiation. Histogenesis of these tumors is still discussed. Our objective is to specify clinical and pathological characteristics of this rare noeoplasm and to discuss its histogenesis. Retrospective study of eight cases of gliosarcomas diagnosed between January 1998 and December 2004. Clinical, radiological, therapeutic and follow-up data were reviewed. Histological features and immunohistochemical results were also included in this review. Five patients were male, three women with a median age of 50.7 [range 31-74 years]. Symptoms were dominated by intracranial hypertension and paralysis. The most conmon location was parietal or temporo-parietal [5 cases: 62.5%]. Pathological exam including histochemical and immunohistochemical study confirmed the diagnosis of gliosarcoma in all cases. Sarcomatous component had features of fibrosarcoma in 5 cases, osteosarcoma in 2 cases and malignant fibrous histiocytoma in 1 case. All patients were treated by surgical excision [complete in five cases and partial in three cases]. Adjuvant radiotherapy was received in three cases. One patient was lost on follow-up. Two patients died from postoperative complications and the five remaining patients died with a medium follow up of 9 months [extremes: 2-24 months]. Clinical, radiological and follow-up features of gliosarcomas share great similarities with glioblastomas. Histopathological, histochemical and inmmnohistochemical studies are helpful in accuracy diagnosis. Recent cytogenetic and molecular data support a monoclonal origin for these tumors

Gliosarcoma: report of four cases with immunohistochemical findings

Gliossarcoma (GSa) é uma neoplasia primária rara do sistema nervoso central, caracterizada por padrão histológico bifásico incluindo componentes tanto glial como sarcomatoso. São discutidos os aspectos clínicos, morfológicos e imunohistoquímicos de quatro casos de GSa e seus mecanismos patogêneticos. A relação masculino/feminino foi 3:1. A média de idade foi 39 anos, variando de 19 a 48. Cefaléia foi a manifestação predominante. Todos os pacientes foram submetidos a craniotomia com microcirurgia e ressecção total do tumor. O diagnostico foi suspeitado devido à arquitetura microscópica e foi confirmada por presença de fibras de reticulina através de técnicas de histoquímica. A análise imuno-histoquímica foi positiva para p53 tanto em células gliais como em células sarcomatosas nos quatro casos. EGFR foi localmente positivo em células gliais em apenas um caso. Esses achados apoiam uma origem monoclonal do GSa relacionada com alteração no Tp53, gene supressor de tumor. No entanto, outras vias alternativas na gênese desses tumores não podem ser afastadas.

Gliosarcoma: a case with unusual epithelial feature

Astrocytic tumors, particularly gliosarcoma, may contain epithelial features in the form of trabecular, adenoid, papillary arrangement, and squamous metaplasia. A case of gliosarcoma with unusual epithelial feature is described. The patient was a 60-year-old male with frequent seizures. The mass was 4 cm and in the left frontal lobe. Trabecular or rarely adenoid arrangement of neoplastic astrocytes was present in the mucinous stroma, and there was a distinctive transition between the trabecular area and typical anaplastic astrocytoma. The tumor cells in the trabecular area showed positive immunostain for glial fibrillary acidic protein, but did not react with various kinds of cytokeratin. The sarcomatous area was undifferentiated and was not labeled by factor-VIII, desmin, and anti-smooth muscle actin. Occurrence and histogenesis of epithelial features in gliosarcoma are reviewed. The importance to recognize the existence of epithelial feature in malignant astrocytic tumor is emphasized.

A clinico-pathological study of 29 cases of gliosarcoma with special reference to two unique variants.

In the present series, the clinical and pathological features of 29 patients of gliosarcoma diagnosed over a 12 yr period (1984-1995) are reviewed. Gliosarcomas constituted 0.48 per cent of all intracranial tumours and 4.9 per cent of all cases of glioblastoma multiforme. Most patients (68.6%) with these tumours were above 40 yr of age. However, an interesting observation in the present series was that 10.3 per cent of patients (3/29) were below 14 yr of age, the youngest being 9 months. A male preponderance was noted and the temporal lobe was involved in 55 per cent patients. Histologically, in 25 of the 29 tumours, the sarcomatous component had the appearance of fibrosarcoma. Tumours from 4 patients were unique in that one showed rhabdomyoblastic differentiation in the mesenchymal areas as confirmed by immunohistochemical stains and electron microscopy (gliomyosarcoma). In three others, the neoplastic spindle cell component was closely associated with discrete areas of osteogenic sarcoma. Follow up in 12 patients (including the 4 patients with unique variants) revealed poor outcome similar to glioblastomas. All of them died within 1 month to 1.5 yr following surgery and postoperative radiotherapy. This study possibly represents the most comprehensive and largest series of gliosarcomas being reported from India.

Gliosarcomas: pathological spectrum.

Pathological spectrum as seen in sixteen cases of gliosarcomas out of 81 cases of glioblastomas is described. Temporal lobe involvement (37.5%) and fibrosarcomatous pattern (62.5%) were found to be most frequent. Osteochondromatous element was found in recurrence of one gliosarcoma. Minimal criteria for diagnosis, pitfalls in diagnosis, differential diagnosis and histogenesis of gliosarcoma are discussed.