The Role of Fibroblast Activation Protein in Glioblastoma and Gliosarcoma: A Comparison of Tissue, 68Ga-FAPI-46 PET Data, and Survival Data.

Despite their unique histologic features, gliosarcomas belong to the group of glioblastomas and are treated according to the same standards. Fibroblast activation protein (FAP) is a component of a tumor-specific subpopulation of fibroblasts that plays a critical role in tumor growth and invasion. Some case studies suggest an elevated expression of FAP in glioblastoma and a particularly strong expression in gliosarcoma attributed to traits of predominant mesenchymal differentiation. However, the prognostic impact of FAP and its diagnostic and therapeutic potential remain unclear. Here, we investigate the clinical relevance of FAP expression in gliosarcoma and glioblastoma and how it correlates with 68Ga-FAP inhibitor (FAPI)-46 PET uptake. Methods: Patients diagnosed with gliosarcoma or glioblastoma without sarcomatous differentiation with an overall survival of less than 2.5 y were enrolled. Histologic examination included immunohistochemistry and semiquantitative scoring of FAP (0-3, with higher values indicating stronger expression). Additionally, 68Ga-FAPI-46 PET scans were performed in a subset of glioblastomas without sarcomatous differentiation patients. The clinical SUVs were correlated with FAP expression levels in surgically derived tumor tissue and relevant prognostic factors. Results: Of the 61 patients who were enrolled, 13 of them had gliosarcoma. Immunohistochemistry revealed significantly more FAP in gliosarcomas than in glioblastomas without sarcomatous differentiation of tumor tissue (P < 0.0001). In the latter, FAP expression was confined to the perivascular space, whereas neoplastic cells additionally expressed FAP in gliosarcoma. A significant correlation of immunohistochemical FAP with SUVmean and SUVpeak of 68Ga-FAPI-46 PET indicates that clinical tracer uptake represents FAP expression of the tumor. Although gliosarcomas express higher levels of FAP than do glioblastomas without sarcomatous differentiation, overall survival does not significantly differ between the groups. Conclusion: The analysis reveals a significant correlation between SUVmean and SUVpeak in 68Ga-FAPI-46 PET and immunohistochemical FAP expression. This study indicates that FAP expression is much more abundant in the gliosarcoma subgroup of glioblastomas. This could open not only a diagnostic but also a therapeutic gap, since FAP could be explored as a theranostic target to enhance survival in a distinct subgroup of high-risk brain tumor patients with poor survival prognosis.

Transformation of IDH-wildtype glioblastoma to gliosarcoma with features of osteosarcoma.

Gliosarcoma (GS) is a rare variant of IDH-wildtype glioblastoma. It is classified as grade 4 in the latest WHO CNS classification of both glial and mesenchymal components. Gliosarcoma may arise de novo or secondary from glioblastoma. It occurs in up to 2% of patients diagnosed with glioblastoma. We present a case report of a 51-year-old patient who was initially diagnosed with glioblastoma multiforme, which transformed into secondary gliosarcoma with an osteosarcoma component 16 months after the initial diagnosis. We believe that increasing reporting of secondary gliosarcoma (sGS) will be helpful in understanding, diagnosing and providing more effective treatment for this cancer.

Molecular signature of stem-like glioma cells (SLGCs) from human glioblastoma and gliosarcoma.

Glioblastoma multiforme (GBM) and the GBM variant gliosarcoma (GS) are among the tumors with the highest morbidity and mortality, providing only palliation. Stem-like glioma cells (SLGCs) are involved in tumor initiation, progression, therapy resistance, and relapse. The identification of general features of SLGCs could contribute to the development of more efficient therapies. Commercially available protein arrays were used to determine the cell surface signature of eight SLGC lines from GBMs, one SLGC line obtained from a xenotransplanted GBM-derived SLGC line, and three SLGC lines from GSs. By means of non-negative matrix factorization expression metaprofiles were calculated. Using the cophenetic correlation coefficient (CCC) five metaprofiles (MPs) were identified, which are characterized by specific combinations of 7-12 factors. Furthermore, the expression of several factors, that are associated with GBM prognosis, GBM subtypes, SLGC differentiation stages, or neural identity was evaluated. The investigation encompassed 24 distinct SLGC lines, four of which were derived from xenotransplanted SLGCs, and included the SLGC lines characterized by the metaprofiles. It turned out that all SLGC lines expressed the epidermal growth factor EGFR and EGFR ligands, often in the presence of additional receptor tyrosine kinases. Moreover, all SLGC lines displayed a neural signature and the IDH1 wildtype, but differed in their p53 and PTEN status. Pearson Correlation analysis identified a positive association between the pluripotency factor Sox2 and the expression of FABP7, Musashi, CD133, GFAP, but not with MGMT or Hif1α. Spherical growth, however, was positively correlated with high levels of Hif1α, CDK4, PTEN, and PDGFRß, whereas correlations with stemness factors or MGMT (MGMT expression and promoter methylation) were low or missing. Factors highly expressed by all SLGC lines, irrespective of their degree of stemness and growth behavior, are Cathepsin-D, CD99, EMMPRIN/CD147, Intß1, the Galectins 3 and 3b, and N-Cadherin.

An autopsy case of primary gliosarcoma with multiple extracranial metastases: pathology after administration of bevacizumab and genetic profile.

Gliosarcoma (GS), a morphological variant of glioblastoma, pathologically shows a biphasic pattern with gliomatous and sarcomatous components. It has been reported that GS has much higher metastatic capacity than glioblastoma. A few reports on the pathology of the extracranial metastasis of GS have shown that metastatic lesions had a sarcomatous component alone or a mixture of gliomatous and sarcomatous ones. Therefore, it is considered that GS tends to disseminate hematogenously due to its mesenchymal sarcomatous component. Herein, we report an autopsy case of GS with multiple extracranial metastases treated by craniotomy, radiotherapy, and bevacizumab. In this case, metastatic lesions at autopsy contained a gliomatous component alone, but no sarcomatous component. In addition, the sarcomatous component disappeared from the intracranial lesion at autopsy after the administration of bevacizumab. In this report, we discuss the clinical course and pathological findings at the initial state, recurrence, and autopsy, including the results of whole-genome analysis.

Utilidad del coeficiente de difusión aparente en la evaluación de la sustancia blanca para diferenciar glioblastoma de metástasis cerebral / Usefulness of the apparent diffusion coefficient for the evaluation of the white matter to differentiate between glioblastoma and brain metastases

Objetivo. Encontrar diferencias significativas en la sustancia blanca peritumoral aparentemente normal entre gliobastoma y metástasis cerebral mediante la valoración del coeficiente de difusión aparente (CDA). Material y métodos. Se revisaron retrospectivamente resonancias magnéticas de 42 pacientes con histopatología de glioblastomas y 42 pacientes con metástasis cerebral única. Se realizaron mediciones de intensidad de señal en el mapa de CDA sobre la sustancia blanca peritumoral aparentemente normal (SBPAN) y la sustancia blanca peritumoral alterada (SBPAlt). Se diseñaron índices normalizados de CDA utilizando valores medidos en la sustancia blanca occipital contralateral como referencia. Se compararon las medias para establecer diferencias entre ambos tipos de tumores. Se calculó el área bajo la curva (ROC) y se estimaron la sensibilidad y la especificidad para las mediciones realizadas. Resultados. Los pacientes con glioblastoma presentaron con mayor frecuencia lesiones supratentoriales y compromiso del cuerpo calloso que los pacientes con metástasis cerebral. El diámetro máximo del área de realce tras la inyección de contraste fue mayor en los glioblastomas (p < 0,001). El valor mínimo de CDA medido en la SBPAN fue mayor en los glioblastomas que en las metástasis (p = 0,002). Solo se encontraron diferencias significativas en el índice de CDA para el valor mínimo de CDA en la SBPAN. Los valores de sensibilidad y especificidad fueron inferiores al 70% para las variables evaluadas. Conclusiones. Existen diferencias en los valores del CDA de la SBPAN entre glioblastomas y metástasis, pero la magnitud de dicha diferencia es escasa y su aplicación en la práctica clínica aún es limitada (AU)

Objective. To determine whether there are significant differences in the apparent diffusion coefficient (ADC) between the apparently normal peritumor white matter surrounding glioblastomas and that surrounding brain metastases. Material and methods. We retrospectively reviewed 42 patients with histologically confirmed glioblastomas and 42 patients with a single cerebral metastasis. We measured the signal intensity in the apparently normal peritumor white matter and in the abnormal peritumor white matter on the ADC maps. We used mean ADC values in the contralateral occipital white matter as a reference from which to design normalized ADC indices. We compared mean values between the two tumor types. We calculated the area under the receiver operator characteristic curve and estimated the sensitivity and specificity of the measurements taken. Results. Supratentorial lesions and compromise of the corpus callosum were more common in patients with glioblastoma than in patients with brain metastases. The maximum diameter of the enhanced area after injection of a contrast agent was greater in the glioblastomas (p < 0.001). The minimum ADC value measured in the apparently normal peritumor white matter was higher for the glioblastomas than for the metastases (p = 0.002). Significant differences in the ADC index were found only for the minimum ADC value in apparently normal peritumor white matter. The sensitivity and specificity were less than 70% for all variables analyzed. Conclusions. There are differences in the ADC values of apparently normal peritumor white matter between glioblastomas and cerebral metastases, but the magnitude of these differences is slight and the application of these differences in clinical practice is still limited (AU)

Metástasis medulares de gliosarcoma. Presentación de un caso y revisión de la literatura / Spinal cord metastasis from gliosarcoma. Case report and review of the literature

INTRODUCCIÓN: El gliosarcoma es un tumor cerebral primario infrecuente similar al glioblastoma multiforme. En contrapartida al glioblastoma multiforme, debido a su componente sarcomatoso, los gliosarcomas tienen mayor tendencia a realizar metástasis extracraneales (11% de los casos). A pesar de ello, las metástasis medulares del gliosarcoma cerebral primario son extremadamente infrecuentes. CASO CLÍNICO: Se presenta el caso de una paciente intervenida de gliosarcoma cerebral que en el curso evolutivo de su enfermedad presenta una paraparesia, diagnosticándose e interviniéndose de metástasis medular de gliosarcoma. Realizamos una revisión sistemática de la literatura sobre los casos descritos de metástasis intramedular, sus características, el tratamiento realizado y el pronóstico. CONCLUSIONES: Únicamente se han descrito 4 casos de metástasis intramedular de gliosarcoma en la literatura. Se trata de una entidad infrecuente pero en la que debemos pensar ante la aparición de clínica medular en el curso evolutivo de un paciente con gliosarcoma cerebral

INTRODUCTION: Gliosarcoma is a rare neoplasm of the central nervous system, similar to glioblastoma multiforme. In contrast to glioblastoma, it is characterised by its propensity for extracranial metastasis (11% of the cases) due to its sarcomatous component. Intramedullary metastasis from primary gliosarcoma is extremely rare. CASE REPORT: A patient who had surgery for primary cerebral gliosarcoma developed paraparsis during the course of the disease. A magnetic resonance image showed an intramedullaryspinal cord metastasis requiring surgical treatment. This article reviews the literature on intramedullary spinal cord metastasis from gliosarcoma, and highlights the characteristics, treatment and overall survival. CONCLUSIONS: Only 4 cases of intramedullary gliosarcoma metastasis are described in the literature. This extremely rare entity should be suspected with the onset of spinal cord symptoms during the course of primary cerebral gliosarcoma

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.

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.(AU)

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.(AU)

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

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.

Oligoastrocitoma originado en teratoma quístico inmaduro de ovario. Descripción de un caso / Oligoastrocytoma arising in an ovarian immature cystic teratoma. A case report

Los teratomas inmaduros del ovario representan menos del 1% de los tumores de ovario. Su malignización somática es infrecuente. Los tumores de origen neuroepitelial son raros en los teratomas, y cuando están presentes corresponden a tumores tipo glioblastoma, neurocitomas o tumores derivados de las células neuroectodérmicas primitivas. Presentamos el caso de una mujer con tumoración sólido-quística de ovario, a quien se realizó el diagnóstico de oligoastrocitoma (grado II), originado en un teratoma inmaduro de ovario. No existen en la actualidad casos publicados de oligoastrocitoma asociados a teratoma. La conducta terapéutica fue el tratamiento quirúrgico inicial y posterior control clínico-ginecológico. En la actualidad la paciente se encuentra libre de enfermedad(AU)

We present a case of a solid cystic tumour of the ovary diagnosed as a grade II oligoastrocytoma, originating from a grade II immature ovarian teratoma. To our knowledge, this is the first reported case of ovarian oligoastrocytoma. The patient underwent surgical resection with frequent follow-ups. Presently, she is alive and free of disease. Immature teratomas of the ovary account for less than 1% of all ovarian tumours. Secondary malignant change is infrequent. Neuroepithelial tumours arising in immature teratomas are very rare and may correspond to glioblastoma tumours, neurocytoma or tumours derived from primitive neuroectodermal cells(AU)

Expression of EphrinB2 and EphB4 in glioma tissues correlated to the progression of glioma and the prognosis of glioblastoma patients

OBJECTIVE: The ligand EphrinB2 and the corresponding receptor EphB4 are up-regulated and involved in tumour growth in various human cancers. However, little is known about how this receptor-ligand complex contributes to the progression of glioma. This prompted us to study the association between the expressions of EphrinB2 and EphB4, clinicopathological variables, and glioma patient outcome. METHODS: Immunohistochemical staining was performed to detect the expression patterns of EphrinB2 and EphB4 in the biopsies from 96 patients with primary gliomas. Kaplan-Meier survival and Cox regression analyses were performed to evaluate the prognosis of patients. RESULTS: Immunohistochemical analysis revealed that the expression of EphrinB2 was significantly correlated with that of EphB4 (r=0.86, p=0.002). EphrinB2 and EphB4 were significantly associated with the Karnofsky performance scale (KPS) score and World Health Organization grades of patients with gliomas, respectively. Especially, the positive expression rates of EphrinB2 and EphB4 were significantly higher in patients with higher grade (both p=0.001) and lower KPS score (p=0.002 and 0.003, respectively). Multivariate Cox regression analysis revealed that EphrinB2 and EphB4 expressions were both independent prognostic factors for progress-free survival of glioblastoma patients (both p=0.02). CONCLUSION: Our data indicated for the first time that EphrinB2 and EphB4 expressions increase according to the histopathological grade and KPS score of glioma, and their expression levels are related to the progression-free survival of glioblastoma patients (AU)

Cancer stem cells and brain tumors

Besides the role of normal stem cells in organogenesis, cancer stem cells are thought to be crucial for tumorigenesis. Most current research on human tumors is focused on molecular and cellular analysis of the bulk tumor mass. However, evidence in leukemia and, more recently, in solid tumors suggests that the tumor cell population is heterogeneous. In recent years, several groups have described the existence of a cancer stem cell population in different brain tumors. These neural cancer stem cells (NCSC) can be isolated by cell sorting of dissociated suspensions of tumor cells for the neural stem cell marker CD133. These CD133+ cells -which also express nestin, an intermediate filament that is another neural stem cell marker- represent a small fraction of the entire brain tumor population. The stem-like cancer cells appear to be solely responsible for propagating the disease in laboratory models. A promising new approach to treating glioblastoma proposes targeting cancer stem cells. Here, we summarize progress in delineating NCSC and the implications of the discovery of this cell population in human brain tumors (AU)

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Gliosarcoma con diferenciación adenoide y fibras de Rosenthal. Presentación de un caso / Gliosarcoma with adenoid differentiation and Rosenthal fibers

Introducción: El gliosarcoma es una variante rara de glioblastoma que se caracteriza por un patrón bifásico en el que alternan áreas de diferenciación glial y mesenquimal. La presencia de alteraciones genéticas idénticas en los componentes glial y sarcomatoso apoya la idea de un origen monoclonal del gliosarcoma. Pacientes y métodos: Presentamos un caso de gliosarcoma con diferenciación adenoide y fibras de Rosenthal. Conclusiones: La existencia de fibras de Rosenthal es un hallazgo muy poco habitual en el seno de tumoraciones gliales de alto grado

Introduction: Gliosarcoma is a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. The presence of identical genetic alterations in both gliomatous and sarcomatous components strongly supports the concept of a monoclonal origin of gliosarcoma. Patients and methods: We report a case of gliosarcoma with adenoid differentiation and Rosenthal fibers. Conclusions: The presence of Rosenthal fibers is a very uncommon finding in high grade glial neoplasms

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.

¿Es el fibrosarcoma primitivo cerebralla fase final de la evolucióndel gliosarcoma? / Is primitive brain fibrosarcoma the end stage in the evolution of gliosarcoma?

El gliosarcoma es un tumor cerebral poco frecuente que viene definido por una proliferación bifásica en la que toman parte: a) una fase gliomatosa, habitualmente un glioblastoma, con expresión de GFAP y negatividad para la Vimentina; b) una fase conjuntiva con expresión de Vimentina y negatividad a la GFAP. Por su parte, el fibrosarcoma cerebral primitivo es un tumor muy infrecuente, que se define por una proliferación de células fusiformes, capaces de expresar Vimentina, incapaces de expresar GFAP y que producen abundantes fibras reticulares y, ocasionalmente, colágenas. En nuestro medio hemos estudiado dos casos de gliosarcoma por medio del cultivo de tejidos y por medio del cultivo orgánico. En ambos casos, el cultivo de tejidos demostró la población dual, en forma de colonias celulares diferentes, aun dentro del mismo cultivo. Por su parte, el cultivo orgánico demostró el crecimiento doble en las primeras fases del crecimiento, en tanto que el cabo del tiempo, la fase conjuntiva va predominando sobre la glial, hasta que esta última desaparece. En consecuencia, se plantea la posibilidad de que el fibrosarcoma primitivo cerebral represente la fase final de un gliosarcoma en el que el componente conjuntivo ha hecho desaparecer el componente glial inicial (AU)

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.