Gliosarcomas: magnetic resonance imaging findings / Gliossarcomas: achados de ressonância magnética

Abstract Background: Central nervous system (CNS) gliosarcoma (GSM) is a rare primary neoplasm characterized by the presence of glial and sarcomatous components. Objective: In this report, we describe the clinical and neuroimaging aspects of three cases of GSM and correlate these aspects with pathological findings. We also provide a brief review of relevant literature. Methods: Three patients were evaluated with magnetic resonance imaging (MRI), and biopsies confirmed the diagnosis of primary GSM, without previous radiotherapy. Results: The analysis of conventional sequences (T1, T1 after contrast injection, T2, Fluid attenuation inversion recovery, SWI and DWI/ADC map) and advanced (proton 1H MR spectroscopy and perfusion) revealed an irregular, necrotic aspect of the lesion, peritumoral edema/infiltration and isointensity of the solid component on a T2-weighted image. These features were associated with irregular and peripheral contrast enhancement, lipid and lactate peaks, increased choline and creatine levels in proton spectroscopy, increased relative cerebral blood volume (rCBV) in perfusion, multifocality and drop metastasis in one of the cases. Conclusion: These findings are discussed in relation to the general characteristics of GSM reported in the literature.

Resumo Introdução: O gliossarcoma (GSM) do sistema nervoso central (SNC) é uma neoplasia primária rara, caracterizada pela presença de componentes gliais e sarcomatosos. Objetivo: Nosso objetivo é descrever os aspectos clínicos e de neuroimagem de três casos com este diagnóstico e correlacioná-los com os achados patológicos. Também foi realizada uma breve revisão da literatura relevante. Métodos: Três pacientes foram avaliados por ressonância magnética (RM), e biópsias confirmaram o diagnóstico de GSM primário, sem radioterapia prévia. Resultados: Foram analisadas as sequências convencionais (T1, T1 após injeção de contraste, T2, FLAIR-fluid attenuation inversion recovery, SWI, DWI/mapa ADC) e as sequências avançadas (espectroscopia de prótons 1H e perfusão), observando-se aspecto necrótico e irregular da lesão, edema/infiltração peritumoral, isointensidade do componente sólido em T2, associada a realce irregular e periférico pelo meio de contraste, pico de lípides e de lactato e aumento dos níveis de colina e creatina na espectroscopia de prótons, aumento do volume sanguíneo cerebral relativo (rCBV) na perfusão, multifocalidade e "drop" mestástase em um dos casos. Conclusão: O presente estudo descreve características do GSM, discutindo as informações na literatura científica, ilustrando algumas particularidades desses tumores.

Extensive Pachymeningeal Dissemination of Glioblastoma Mimicking Chronic Subdural Hematoma: A Case Report

Meningeal dissemination (MDS) of glioblastoma is rare, although its incidence might have been underestimated. MDS of glioblastoma has a fatal course. Thus, rapid and precise diagnosis of MDS is important for further palliative treatment. Unfortunately, MDS of glioblastoma could be diagnosed at a delayed time, causing failure to treat patient optimally. Herein, we present a case of a 56-year-old male with MDS of glioblastoma mimicking chronic subdural hemorrhage (CSDH) after head trauma due to slip down. During treatment for CSDH, MDS of glioblastoma was not controlled appropriately. The patient succumbed to MDS of glioblastoma at 9 weeks after the date of diagnosis of CSDH which could be an MDS.

Gliosarcoma of Cerebello-Pontine Angle: A Case Report and Review of the Literature

Gliosarcoma (GS), known as variant of glioblastoma multiforme, is aggressive and very rare primary central nervous system malignant neoplasm. They are usually located in the supratentorial area with possible direct dural invasion or only reactive dural thickening. However, in this case, GS was located in lateral side of left posterior cranial fossa. A 78-year-old man was admitted to our hospital with 3 month history of continuous dizziness and gait disturbance without past medical history. A gadolinium-enhanced MRI demonstrated 5.6×4.8×3.2 cm sized mass lesion in left posterior cranial fossa, heterogeneously enhanced. The patient underwent left retrosigmoid craniotomy with navigation system. The tumor was combined with 2 components, whitish firm mass and gray colored soft & suckable mass. On pathologic report, the final diagnosis was GS of WHO grade IV. In spite of successful gross total resection of tumor, we were no longer able to treat because of the patient's rejection of adjuvant treatment. The patient survived for nine months without receiving any special treatment from the hospital.

Gliosarcoma in a young patient with neurofibromatosis type 1. case report

ABSTRACT Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder that has variable phenotypic expressivity, with manifestations ranging from cutaneous lesions to functional compromise. It manifests clinically during childhood and adolescence. The NF-1 gene encodes a protein, neurofibromin gene, which acts as a tumor suppressor under normal conditions by regulating another protein that stimulates cell growth and proliferation. In case of alteration, different tumor processes may occur, such as the one seen in a small number of cases. Case presentation: 20-year-old male patient with NF1, who presented café-au-lait spots and developed a glioblastoma, which happens infrequently. Discussion: Immunohistochemistry methods that contribute greatly to prognosis are included to achieve the confirmed diagnosis since the median overall survival of glioblastoma patients is higher in patients with NF1 than in those without said pathological entity. Conclusion: The early diagnosis of the lesions favors a timely management of NF1. These patients require a comprehensive and interdisciplinary management to achieve full rehabilitation.

RESUMEN Introducción. La neurofibromatosis tipo 1 (NF1) es una condición autosómica dominante que presenta una expresividad fenotípica variable, con manifestaciones que van desde lesiones cutáneas hasta compromiso funcional. Se manifiesta clínicamente durante la infancia y la adolescencia; su gen codifica una proteína, la neurofibromina, que actúa como un supresor tumoral en condiciones normales regulando, a su vez, otra proteína que estimula el crecimiento y proliferación celular. En caso de alteración se podrían presentar diferentes procesos tumorales como el que se evidencia en un reducido número de casos. Presentación de caso. Paciente masculino de 20 años con NF1, quien presentaba lesiones cutáneas como manchas color café con leche y desarrolló un glioblastoma, lo cual sucede de manera infrecuente. Discusión. Para obtener el diagnóstico confirmado se incluyen métodos de inmunohistoquímica que contribuyen en gran medida al pronóstico puesto que la mediana de supervivencia global de los pacientes de glioblastoma es mayor en pacientes con NF1 que aquellos sin dicha entidad patológica. Conclusión. El diagnóstico temprano de las lesiones favorece un manejo a tiempo de la NF1. Estos pacientes requieren un manejo integral e interdisciplinar para favorecer su rehabilitación total.

A Stable Secondary Gliosarcoma with Extensive Systemic Metastases: A Case Report

A 63-year-old man complained of intermittent motor weakness of his arm. The magnetic resonance image (MRI) of his brain displayed a high signal lesion in right cingulate gyrus on T2 weighted image. One year later, he showed a stuporous mental status with repeated seizures, and the follow-up brain MRI showed heterogeneously enhanced mass associated with bleeding. He was treated with surgery and radiotherapy for secondary glioblastomas in right cingulate gyrus. One year more later, a mass recurred on the left frontal base, and gliosarcoma was diagnosed. After tumor resection, ventriculoperitoneal shunt, chemotherapy, and re-radiation therapy, all brain lesions were stable. Fourteen months after the diagnosis of gliosarcoma, he complained of dyspnea and back pain. Torso positron emission tomography/computed tomography revealed multiple metastatic lesions in both lungs, pericardium, pleura, liver, lymph nodes, and bones, and metastatic gliosarcoma was diagnosed. One month later, the patient died because of the systemic metastases. We present an unusual case of secondary gliosarcoma with stable brain lesions and extensive systemic metastases.

Gliosarcoma cerebeloso asociado aneurofibromatosis tipo I: presentación de caso / Cerebellar gliosarcoma associated with neurofibromatosis type I: case presentation

El Gliosarcoma es un raro Glioblastoma que contiene tantos elementos gliales comparable con un Glioblastoma como componentes mesenquimal. Aproximadamente entre 2-8% de todos los Glioblastomas están asociados con elementos sarcomatosos. Clínica y genéticamente muy parecido a los Glioblastomas, excepto por la ausencia de amplificación del EGFR. El gliosarcoma es un tumor de alto grado de malignidad y pobre pronóstico, con alta tasa de recurrencia. Presentamos el caso de un paciente masculino de 54 años de edad con diagnóstico de gliosarcoma cerebeloso, asociado a Neurofibromatosis tipo I. La NF I es el síndrome hereditario más común que predispone a la neoplasia, es una enfermedad polifacética asociado no sólo a tumores benignos.

Gliosarcoma are rare glioblastomas that contain an anaplastic glial component comparable to a glioblastoma, as well as,a mesenchymal component, that have a biphasic pattern. Approximately 2-8% of all glioblastomas are associated with a sarcomatous element. Clinically and genetically close to glioblastomas, except for the absence of EGFR amplification. The Gliosarcoma is a high-grade tumor of malignity and poor prognosis, with high rate of recurrence. We present the case of a masculine patient of 54 elderly years, with diagnosis of Gliosarcoma Cerebellar associate to Neurofibromatosis type I. The NF I is the hereditary syndrome more common that predisposes to the tumor, it is a versatile disease that not only becomes a partner of benign tumors.

Clinical outcome of patients with primary gliosarcoma treated with concomitant and adjuvant temozolomide: A single institutional analysis of 27 cases.

CONTEXT AND AIM: The prognosis of primary gliosarcoma (PGS) remains dismal with current treatment modalities. We analyzed the outcome of PGS patients treated with concurrent and adjuvant temozolomide (TMZ). SETTINGS AND DESIGN: Retrospective single institutional analysis. MATERIALS AND METHODS: We retrospectively evaluated 27 patients of PGS treated with radiotherapy (RT) and TMZ during 2007‑2012. STATISTICAL ANALYSIS USED: Overall survival (OS) was estimated by the use of Kaplan Meier method and toxicities were evaluate using common terminology criteria for adverse events version 2.0 (National Cancer Institute, USA). RESULTS: Median age at presentation and Karnofsky performance status was 45 years and 90 respectively and male: female ratio was 20:7. Patients received adjuvant RT to a total dose of 60 Gy at 2 Gy/fraction. All patients except 5 received adjuvant TMZ to a median number of 6 cycles. Grade 2 and 3 hematological toxicity was seen in 8% and 4% of patients respectively during concurrent RT. During adjuvant chemotherapy, 13.6% had Grade 3 thrombocytopenia and 9.5% had Grade 3 neutropenia. Median OS was 16.7 months (1 year and 2 year actuarial OS was 70.8% and 32.6% respectively). Adjuvant TMZ was associated with a better survival (median survival 21.21 vs. 11.93 months; P = 0.0046) on univariate analysis and also on multivariate analysis (hazard ratio 1.82, 95% confidence interval: 1.503‑25.58; P = 0.012). CONCLUSIONS: The results of our study, largest series of patients with PGS treated with concurrent and adjuvant TMZ shows an impressive survival with acceptable toxicity. We suggest TMZ be included in the “standard of care” for this tumor.

Primary Diffuse Leptomeningeal Gliosarcomatosis

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare condition with a fatal outcome, characterized by diffuse infiltration of the leptomeninges by neoplastic glial cells without evidence of primary tumor in the brain or spinal cord parenchyma. In particular, PDLG histologically diagnosed as gliosarcoma is extremely rare, with only 2 cases reported to date. We report a case of primary diffuse leptomeningeal gliosarcomatosis. A 68-year-old man presented with fever, chilling, headache, and a brief episode of mental deterioration. Initial T1-weighted post-contrast brain magnetic resonance imaging (MRI) showed diffuse leptomeningeal enhancement without a definite intraparenchymal lesion. Based on clinical and imaging findings, antiviral treatment was initiated. Despite the treatment, the patient's neurologic symptoms and mental status progressively deteriorated and follow-up MRI showed rapid progression of the disease. A meningeal biopsy revealed gliosarcoma and was conclusive for the diagnosis of primary diffuse leptomeningeal gliosarcomatosis. We suggest the inclusion of PDLG in the potential differential diagnosis of patients who present with nonspecific neurologic symptoms in the presence of leptomeningeal involvement on MRI.

Metaplasia óssea no gliossarcoma: um achado histológico pouco usual. Relato de caso / Osseous metaplasia in gliosarcoma: an unusual histologic finding. Case report

Gliosarcoma (GS) is a malignant neoplasm of the central nervous system that has coexisting glial and mesenchymal components. GSs are rarely related to osseous metaplasia. The authors report a case of GS in a male patient presenting apathy and catatonia. Computed tomography/magnetic resonance imaging showed an expansive process affecting the left frontal lobe. At microscopy, a malignant glioma constituted by highly atypical glial cells intermingled with spindle-shaped cells was identified. The lesion showed areas of necrosis with pseudopalisading formation, focus of osseous metaplasia, and positive immunoexpression of S100, CD99 and vimentin in both elements. Only the sarcomatous component exhibited negative immunoexpression of glial fibrillary acidic protein (GFAP). The diagnosis of GS was then established...

Gliossarcoma (GS) é uma neoplasia maligna do sistema nervoso central que apresenta coexistência de componentes glial e mesenquimal. Raramente, os GS estão associados à metaplasia óssea. Os autores descrevem um caso de GS em paciente masculino apresentando apatia e catatonia. A tomografia computadorizada e a ressonância magnética mostraram um processo expansivo comprometendo o lobo frontal esquerdo. À microscopia, foi identificado um glioma maligno constituído por células gliais extremamente atípicas entremeadas com células fusiformes. A lesão mostrava áreas de necrose com formação de pseudopaliçada, focos de metaplasia óssea e expressão imuno-histoquímica positiva para S100, CD99 e vimentina em ambos os componentes. Somente o componente sarcomatoso exibiu imunoexpressão negativa para proteína glial fibrilar ácida (GFAP). O diagnóstico de GS foi, então, estabelecido...

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.

Gliossarcoma: um desafio clínico e terapêutico / Gliosarcoma: a clinical and therapeuctic challenge

O Gliossarcoma (GSa) é uma neoplasia primária rara do sistema nervoso central, caracterizada por padrão histológico bifásico que inclui os componentes glial e sarcomatoso. Os autores relatam o caso de um paciente masculino, de 49 anos de idade, que apresentou cefaleia como manifestação clínica predominante. O diagnostico foi suspeitado devido à arquitetura microscópica e confirmado pelo estudo imuno-histoquímico. Na terapêutica, foi submetido à craniotomia com microcirurgia para ressecção do tumor e tratamento radioterápico complementar. Dados epidemiológicos, histogênese e achados frequentes em exames de imagem são discutidos, assim como o tratamento e prognóstico.

The gliosarcoma (GSA) is a rare primary neoplasm of the central nervous system characterized by a biphasic histological pattern that includes the glial and sarcomatous components. Here the authors report the case of a 49-year-old male patient who presented headache as predominant clinical manifestation. The diagnosis was suspected on account of microscopic architecture and confirmed by immunohistochemical study. The patient underwent craniotomy with microsurgery for tumor resection and additional radiotherapy. Epidemiological data, histogenesis and common findings on imaging are discussed, as well as treatment and prognosis.

The prognostic impact of O 6- methylguanine DNA methyltransferase and epidermal growth factor receptor expressions on primary gliosarcoma: A clinicopathologic and immunohistochemical study of seven cases at a single institution.

Context: Gliosarcoma is an uncommon variant of glioblastoma characterized by a biphasic tissue pattern of glial and mesenchymal differentiation. O 6- methylguanine DNA methyltransferase (MGMT) is a DNA repair protein that removes mutagenic and cytotoxic adducts from O 6 -guanine in DNA. Lack of MGMT protein expression immunohistochemically is related to drug responses in patients of malignant glioma treated with alkylating agents. Epidermal growth factor receptor (EGFR) is the most frequently amplified gene in glioblastoma and associated with tumor invasiveness, angiogenesis, poor survival, and resistance to radiation therapy. Aims: To elucidate the relationship between the statuses of the MGMT as well as EGFR proteins and the prognosis. The study was undertaken on samples received at the Department of Pathology from 2003 to 2009. Materials and Methods: Clinicopathologic and immunohistochemical study of seven cases was performed. Results: This series included three men and four women with a mean age of 49.3 years at first surgery. The median progression-free survival (PFS) was 22.2 months and 8.6 months for primary tumors with 0 to 1+ and 2+ to 3+ MGMT staining, respectively; the median overall survival (OS) was 27.5 months and 14.2 months for primary tumors with 0 to 1+ and 2+ to 3+ MGMT staining, respectively. The median PFS was 17.2 months and 11.2 months for primary tumors with 0 to 1+ and 2+ to 3+ EGFR staining, respectively; the median OS was 20.4 months and 17.7 months for primary tumors with 0 to 1+ and 2+ to 3+ EGFR staining, respectively. Conclusions: The series showed that MGMT and EGFR protein expressions were both unfavorable prognostic factors for patients with gliosarcoma.

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.

Gliosarcoma of the Cerebellar Hemisphere: a Case Report and Review of the Literature

Gliosarcoma is a rare central nervous system tumor usually located in the supratentorial area. Here we report a rare case of a gliosarcoma that developed in the cerebellar hemisphere in a 70-year-old woman. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain revealed an infratentorial mass of which radiological features were similar to those of glioblastoma. The tumor was diagnosed by pathology as a gliosarcoma. Though rare, gliosarcoma should be considered in the differential diagnosis of infratentorial tumors with radiological features of glioblastoma or metastasis in elderly patients.

Gliosarcoma multicéntrico / Multicentric gliosarcoma

Objetivo. Presentar un caso de esta infrecuente patología; realizar una revisión bibliográfica y analizar su etiología, características clínicas y tratamiento. Descripción. Paciente femenina de 60 años de edad, que consultó por presentar hemiparesia braquiocrural derecha y afasia de expresión de 30 días de evolución. La TAC y RMN evidenciaron lesiones localizadas a nivel parieto-occipital izquierda, parainsular y occipital derecha. El screening oncológico fue negativo. Intervención. Se realizó craniotomía y exéresis subtotal de la lesión parieto-occipital izquierda. La anatomía patológica informó gliosarcoma. Completó tratamiento con radioterapia holocraneana y quimioterapia con temozolamida. La paciente falleció a los diez meses del diagnóstico.

Objetive. We report a rare case of Multicentric Gliosarcoma, we review the literature and analyze its causes, clinical features and treatment.Description. Sixty-year-old female patient who has presented right hemiparesis and motor aphasia for a month. CT and MRI showed lesions at the left parieto-occipital lobes, right occipital and parainsular lobes. Oncologic screening was negative.Intervention. A craniotomy and subtotal excision of parietooccipital lesion was performed. Histological examination revealed gliosarcoma. She received radiotherapy and chemotherapy,however she died ten months after the diagnosis. Conclusion. Multicentric gliosarcoma is very unfrequent. Thereare only two cases reported in the literature. Even so, it must besuspected in multiple cerebral lesions.

Gliosarcoma with Components of Anaplastic Oligodendroglioma and Unclassifiable Spindle Cells: A Case Report

Gliosarcoma is a distinct disease entity that is characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. The tumor in our case was a rare morphologic variant of gliosarcoma with components of anaplastic oligodendroglioma and unclassifiable spindle cells. Spindle cells showed CD34 and S-100 protein immunoreactivity, which was possibly related to peripheral nerve sheath differentiation. This unique feature has not been described previously and so this case expands the spectrum of possible divergent mesenchymal differentiation, and it lends support to pluripotential stem cells being the origin of this tumor.

A Case of Gliosarcoma Associated with Neurofibromatosis Type 1

A rare case of gliosarcoma with neurofibromatosis typeI is presented. The patient was a 33-year-old woman who had headache and vomiting for one week. Multiple neurofibromas over her whole body with many cafe-au-lait spots were present since childhood. At admission, she had no focal neurological deficit and ophthalmologic examination revealed bilateral Lisch nodules. Brain CT and MRI revealed a heterogeneously enhancing mass in the left fronto-parietal region with marked peritumoral edema and mass effect. The tumor was removed gross totally and a gliosarcoma was diagnosed histopathologically. Post operative course was uneventful with resolution of symptom, followed by radiotherapy with 60 Gy. A brief overview is given of this rare case together with the pertinent literature.

CT and MRI manifestations of intracranial gliosarcoma / 中华放射学杂志

Objective To investigate the clinical and characteristic imaging findings of intracranial gliosarcoma. Methods The imaging findings of surgery and pathology proved intracranial gliosarcoma in 15 cases were retrospectively analyzed. There were 10 males and 5 females, ranging in age from 44 to 67 years (mean age 58 years). Results All tumors were located in supratentorium, including 13 cases in the temporal or parietal lobe, 1 cases in the occipital lobe, and 1 cases in the thalamus. Tumors appeared as round or ellipse in shape. The lesions ranged in size from 3 to 9 cm (mean 4.6 cm). CT scan showed mingled hypo and isodensity in 7, hypodense in 4 with CT value from 18 to 22 HU, hyperdense in 4 with the CT value from 48 to 55 HU. Enhancement appeared as an irregular pattern. The margin was clear. Most intracranial gliosarcoma showed perifocal edema. MRI were examined in 6 cases, whichappeared as low signal on T 1WI, and as high signal on T 2WI. There was irregular enhancement of the mass. Conclusion It was difficult to make the correct preoperative diagnosis for gliosarcoma, but it was possible to make a tendency diagnosis using CT or MR combined with the history. Contrast enhanced CT and MRI should be useful in differentiating gliosarcoma from glioblastoma.

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.

Patterns of Invasion in Rat Gliosarcoma

The aim of this study was to investigate the patterns of invasion into the surrounding normal brain tissue in malignant gliomas. The C9L gliosarcoma cell line was used to produce a tumor in the concentration of 2X10 6 cells/microL. The experimental animals, male Sprague-Dawley rats, were anesthetized and secured in a stereotactic frame for left parietal craniectomy and tumor cell injection, and sacrificed in 10 to 14 days. The authors evaluated the patterns of tumor growth such as mass size, invasion site, formation of secondary structures, type of necrosis, and evolvement of blood vessels using routine H-E stain, Miller's elastic stain and immunohistochemical stain for vascular endothelial growth factor(VEGF). The tumor was produced in 8 of 16 cases, which were mostly consisted of malignant spindle cells. Regarding the tumor growth patterns, infiltrative type was observed more frequently than expansion type. Leptomeningeal involvement was observed in 6 cases which showed infiltrative growth pattern, and ventricular dissemination was noted in 3 cases and choroid plexus involvement was found in 1 case. Secondary tumor structures such as perivascular tumor cell aggregates and separate tumor micronodules were observed in 4 cases and 6 cases, respectively. Three types of necrosis were developed in the center of tumor, such as geographic (2 cases), hemorrhagic(2 cases) and ischemic necrosis(1 case). Based on the histologic findings in this experiment, it is presumed that the leptomeningeal dissemination and formation of secondary structures around the primary tumor site might play a significant role in the distant metastasis and recurrence.