The pathological spectrum of desmoplastic infantile gangliogliomas

Desmoplastic Infantile Ganglioglioma: A MAPK Pathway-Driven and Microglia/Macrophage-Rich Neuroepithelial Tumor

MAPK pathway activation has been recurrently observed in desmoplastic infantile ganglioglioma/astrocytoma (DIG/DIA) with reported disproportionally low mutation allele frequencies relative to the apparent high tumor content, suggesting that MAPK pathway alterations may be subclonal. We sought to expand the number of molecularly profiled cases and investigate if tumor cell composition could account for the observed low mutation allele frequencies. Molecular (targeted neuro-oncology next-generation sequencing/RNA sequencing and OncoScan microarray) and immunohistochemical (CD68-PGM1/CD163/CD14/CD11c/lysozyme/CD3/CD20/CD34/PD-L1) studies were performed in 7 DIG. Activating MAPK pathway alterations were identified in 4 (57%) cases: 3 had a BRAF mutation (V600E/V600D/V600_W604delinsDQTDG, at 8%–27% variant allele frequency) and 1 showed a TPM3-NTRK1 fusion. Copy number changes were infrequent and nonrecurrent. All tumors had at least 30% of cells morphologically and immunophenotypically consistent with microglial/macrophage lineage. Two subtotally resected tumors regrew; 1 was re-excised and received adjuvant treatment (chemotherapy/targeted therapy), with clinical response to targeted therapy only. Even with residual tumor, all patients are alive (median follow-up, 83 months; 19–139). This study further supports DIG as another MAPK pathway-driven neuroepithelial tumor, thus expanding potential treatment options for tumors not amenable to surgical cure, and suggests that DIG is a microglia/macrophage-rich neuroepithelial tumor with frequent low driver mutation allele frequencies.

Mixed Solid and Cystic Mass in an Infant

Desmoplastic infantile tumors are rare supratentorial brain tumors that occur in pediatric patients. Desmoplastic infantile tumors are made up of 2 subtypes: desmoplastic infantile gangliogliomas and desmoplastic infantile astrocytomas. Desmoplastic infantile tumors are often identifiable on imaging on the basis of multiple characteristics. Nevertheless, pathologic analysis is required to confirm the diagnosis, particularly when the imaging features are atypical. Here, the radiology findings, surgical approach and subsequent management, and pathology of a desmoplastic infantile ganglioglioma are described.

Inflammatory myofibroblastic lung tumor transforming into intracranial desmoplastic noninfantile ganglioglioma: A case report and literature review

RATIONALE

Inflammatory myofibroblastic tumor (IMT) of the lung often arises from excessive inflammatory response. It is one of the rare benign tumors of the lung, while desmoplastic noninfant gangliogliomas (DNIG), on the contrary, are rare intracranial benign tumors often seen in children within the first one and a half years of life.

PATIENT CONCERNS

We present a 12-year-old girl with 2 months history of none productive cough and right-sided chest pain.

DIAGNOSES

Computer tomography scan of the chest revealed a soft tissue mass at the right upper lobe which was consistent with IMT. Histopathologic examination confirmed the diagnosis of IMT.

INTERVENTIONS

Thoracic surgery was successfully carried out and she further received radiotherapy. The patient recovered initially.

OUTCOMES

Two years later, she complained of seizures during follow-up. Magnetic resonance imaging of the head revealed DNIG. We achieved total resection of the major lesions and she was further treated with radiotherapy. She is currently well and in school. Histopathologic examination confirmed the diagnosis of DNIG.

LESIONS

We speculate that IMT might have transformed into intracranial DNIG through metastatic process or as a result of genetic mutations or chromosomal abrasions.

Novel suprasellar location of desmoplastic infantile astrocytoma and ganglioglioma: a single institution's experience

OBJECTIVE

The aim of this study was to describe the clinical presentation, imaging appearance, and differential outcomes based on tumor location in 7 patients with desmoplastic infantile astrocytoma and desmoplastic infantile gangliogliomas (DIA/DIG).

METHODS

Data of 7 patients with histopathology-proven DIA/DIGs and preoperative imaging were retrospectively reviewed, and age, sex, clinical presentation, imaging characteristics, tumor location, surgical procedure, postoperative morbidity, and overall mortality were recorded.

RESULTS

Two subgroups of patients with DIA/DIGs were found to exist based on whether their tumor was located in the cerebral hemispheres or suprasellar region. Nearly all patients presented with rapidly enlarging head circumference regardless of tumor location. However, ocular abnormalities, including nystagmus and preference for downward gaze, were specific for patients with suprasellar disease. These patients experienced significant postoperative complications and had poor long-term outcomes. In contrast, patients with hemispheric tumors underwent more extensive resection than patients with suprasellar tumors, had uneventful postoperative courses, and had no documented long-term comorbidities.

CONCLUSIONS

Postoperative course and long-term outcome for patients with DIA/DIGs were correlated to the anatomical location and radiographic appearance of their tumor at presentation, despite having histologically and molecularly indistinguishable, WHO grade I tumors.

Desmoplastic Infantile Ganglioglioma/Astrocytoma (DIG/DIA) Are Distinct Entities with Frequent BRAFV600 Mutations

Desmoplastic infantile ganglioglioma (DIG) and desmoplastic infantile astrocytoma (DIA) are extremely rare tumors that typically arise in infancy; however, these entities have not been well characterized in terms of genetic alterations or clinical outcomes. Here, through a multi-institutional collaboration, the largest cohort of DIG/DIA to date is examined using advanced laboratory and data processing techniques. Targeted DNA exome sequencing and DNA methylation profiling were performed on tumor specimens obtained from different patients (n = 8) diagnosed histologically as DIG/DIGA. Two of these cases clustered with other tumor entities, and were excluded from analysis. The remaining 16 cases were confirmed to be DIG/DIA by histology and by DNA methylation profiling. Somatic BRAF gene mutations were discovered in 7 instances (43.8%); 4 were BRAFV600E mutations, and 3 were BRAFV600D mutations. Three instances of malignant transformation were found, and sequencing of the recurrence demonstrated a new TP53 mutation in one case, new ATRX deletion in one case, and in the third case, the original tumor harbored an EML4-ALK fusion, also present at recurrence. DIG/DIA are distinct pathologic entities that frequently harbor BRAFV600 mutations. Complete surgical resection is the ideal treatment, and overall prognosis is excellent. While, the small sample size and incomplete surgical records limit a definitive conclusion about the risk of tumor recurrence, the risk appears quite low. In rare cases with wild-type BRAF, malignant progression can be observed, frequently with the acquisition of other genetic alterations.Implications: DIG/DIA are a distinct molecular entity, with a subset frequently harboring either BRAF V600E or BRAF V600D mutations. Mol Cancer Res; 16(10); 1491-8. ©2018 AACR.

Mixed neuronal-glial tumor in the temporal lobe of an infant: a case report

Background

Tumors that arise in the temporal lobes of infants and spread to the neural system are limited to several diagnoses. Herein, we present an infantile case of a temporal tumor showing neuronal and glial differentiation.

Case presentation

The patient was a 9-month-old boy with low body weight due to intrauterine growth retardation. At 9 months after birth, he presented partial seizures. Computed tomography scanning revealed a mass (35 * 40 mm) in the left temporal lobe. Isointensity was noted on magnetic resonance T1-weighted images and fluid attenuation inversion recovery images. The tumor was heterogeneously enhanced with gadolinium. Positron emission tomography showed high methionine uptake in the tumor. During surgery, the tumor, which was elastic and soft and bled easily, was gross totally resected. A moderately clear boundary was noted between the tumor and normal brain parenchyma. Histologically, the tumor mainly comprised a ganglioglioma-like portion and short spindle cells at different densities. The former was immunohistochemically positive for some kinds of neuronal markers including synaptophysin. The spindle cells were positive for glial fibrillary acidic protein, but desmoplasia was not observed.

Discussion

The tumor contained both neuronal and glial elements; the former were the main constituents of the tumor and included several ganglion-like cells. Because neuronal elements gradually transited to glial cells, a mixed neuronal-glial tumor was diagnosed.

Virtual Slides

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Clinical heterogeneity of desmoplastic infantile ganglioglioma: a case series and literature review

Desmoplastic infantile gangliogliomas (DIG) are intracranial tumors described in 1987 as benign lesions of infancy. A literature review and the clinical course of 3 patients reported herein suggest that the initial description should be amended. Nearly 23% of DIG cases occur in children older than 24 months. Approximately 40% of DIG cases require additional medical, radiation, and/or further surgical intervention, and 15% of infants and children develop leptomeningeal spread or die from DIG. Such adverse outcomes, combined with the recognition that DIG represents a heterogeneous disease, underscore the need for an expanded biological and molecular investigation.

Desmoplastic infantile and non-infantile ganglioglioma. Review of the literature

Desmoplastic gangliogliomas (DIG) are rare primary neoplasms that comprise 0.5-1.0% of all intracranial tumors. Clinically, there are two forms of DIG, the infantile and the non-infantile. These tumors invariably arise in the supratentorial region and commonly involve more than one lobe, preferentially the temporal and frontal. On neuroimaging are seen as large hypodense cystic masses with a solid isodense or slightly hyperdense superficial portion. The histologic diagnosis is characterized by the presence of three different cell lines: astrocytic, neuronal, and primitive neuroectodermal marker sites, which were demonstrable. The treatment of choice is radical surgical excision, and if this is done, achieved complete healing of the patient does not require additional treatment. A literature review of DIG was compiled through Medline/Ovid using the keywords "desmoplastic infantile ganglioglioma", "desmoplastic non-infantile ganglioglioma" covering the years 1984-2009. We present a review of a total of 113 cases of infantile (94) and non-infantile gangliogliomas (19) published to date, examining the clinical, radiologic, surgical, and pathological aspects, as well as the outcome. Desmoplastic gangliogliomas represent a rare tumor group with two well-defined age groups, the children and non-children. Desmoplastic infantile gangliogliomas are the most common and occur in children below 5 years of age, and the large majority of them present within the first year of life. Surgery is the treatment of choice and no complementary treatment is needed in cases of complete tumor resection.

Desmoplastic infantile ganglioglioma with calcification

Desmoplastic infantile gangliogliomas (DIGs) are rare intracranial, cystic tumors, usually detected within the first 2 years of life. Histologically, these tumors are characterized by intense desmoplasia and a divergent astrocytic and neuronal differentiation. Less than 60 well-documented cases of this extremely rare tumor are reported in the literature. We present the case of a 10-month-old male child presenting with a large, cystic, intracranial lesion and having the characteristic histological features of a DIG. In addition, the lesion also showed focal areas of calcification within the tumor, not usually considered a feature of this entity. The present case extends the reported spectrum of this rare entity and describes the unusual occurrence of calcification within the lesion.

Desmoplastic infantile ganglioglioma: a questionably benign tumour

Desmoplastic infantile ganglioglioma is a rare intracranial tumour of childhood that involves the cerebral cortex and the leptomeninges. We report two patients with desmoplastic infantile gangliogliomas and multiple cerebrospinal metastases. To our knowledge, only two similar cases have been reported in the published literature. Pathologically, this rare intracranial tumour shows glial and ganglionic differentiation, accompanied by an extreme desmoplastic reaction. These are low-grade neoplasms that are questionably benign.

Desmoplastic infantile ganglioglioma: MRI and histological findings case report

Desmoplastic infantile gangliogliomas (DIG) are rare intracranial tumors occurring during the 1st year of life. They arise invariably in the supratentorial region and have a great size at presentation, commonly involving more than one lobe. They are composed of a solid peripheral component of variable size, which involves the superficial cerebral cortex and the leptomeninges, and a large cystic part. Despite the great size at presentation and occasional mitotic activity in the variable undifferentiated component, this entity constitutes a distinct clinicopathological entity with benign prognosis. We hereby present the MRI and histological findings of two cases of DIG in infants aged 9 and 10 months, respectively.

Desmoplastic infantile ganglioglioma: A rare tumor with an unusual presentation

Desmoplastic infantile ganglioglioma (World Health Organization grade I) is a rare neoplasm. Despite their common large size and spectacular radiologic and histologic features, the prognosis after surgical resection is good. We present a new case of this tumor in a 14-month-old boy with a recent history of intracranial hypertension. Magnetic resonance imaging revealed a large tumor involving the left collateral trigone with dilatation of the lateral ventricles. Surgery revealed two separate solid tumors: one in the left falco-tentorial region and the other in the left rolandic area. Microscopic examination showed a proliferation of neoplastic astrocytes in reticulin-rich desmoplastic stroma associated with scattered ganglion cells. One year after surgery follow-up magnetic resonance imaging did not show tumor progression.

Postoperative Regression of Desmoplastic Infantile Gangliogliomas: Report of Two Cases

OBJECTIVE AND IMPORTANCE

Desmoplastic infantile gangliogliomas (DIGs) are extremely rare tumors that respond well to treatment. However, their biological behavior remains to be clarified. We describe two patients whose DIGs spontaneously regressed after surgery, without adjuvant therapy.

CLINICAL PRESENTATION

A 9-month-old girl presented with left hemiparesis, and a 6-month-old boy presented with increasing head circumference. For both patients, neuroimaging demonstrated a huge cystic tumor that included a solid portion and was widely attached to the dura. Gadolinium-diethylenetriamine penta-acetic acid produced strong enhancement.

INTERVENTION

One patient underwent partial and the other subtotal tumor removal. Histologically, both tumors were diagnosed as DIGs. Postoperatively, the residual tumors were monitored without adjuvant therapy, and both regressed in several months.

CONCLUSION

Our experience suggests that DIGs may include a subgroup of tumors with a tendency for spontaneous regression, possibly attributable to the induction of apoptosis.

Glioneuronal tumors of the central nervous system

Advances in the immunohistochemical detection of neuron-specific and neuronal-associated antigens have resulted in the discovery of neuronal elements in certain primary human brain tumors. The results have been not only to expand what neuropathologists commonly recognize as gangliogliomas, including the tumors now known as glioneurocytic tumor with neuropil rosettes and papillary ganglioneuroma, but also to expand the spectrum of tumor types to now include tumors such as central neurocytoma, dysembryoplastic neuroepithelial tumor, and desmoplastic infantile ganglioglioma. These discoveries have helped us to better understand the biology of these tumors and to refine our classification of them. Distinctions among these tumors include sites of predilection, such as the temporal lobe with the dysembryoplastic neuroepithelial tumors, and a spectrum of clinical aggressiveness that spans indolent "quasi-hamartomatous" lesions, such as the dysembryoplastic neuroepithelial tumor, to high-grade, highly aggressive tumors, such as the supratentorial primitive neuroectodermal tumor (World Health Organization Grade IV). Many of these tumors also commonly exhibit a glial component, as determined by both their histologic appearance and their immunoreactivity for glial fibrillary acidic protein. This review covers these recently described lesions, including the desmoplastic infantile ganglioglioma, the dysembryoplastic neuroepithelial tumor, the papillary glioneuronal tumor, the glioneuronal tumor with neuropil rosettes, and the mixed glioblastoma-cerebral neuroblastoma (supratentorial primitive neuroectodermal tumor), as well as the known tumors, ganglioglioma, medulloepithelioma, and medulloblastoma. For pathologists confronted by this growing array of tumors and subtypes, it is appropriate to focus on them and understand the differential diagnosis to be considered when confronted by them.

Desmoplastic infantile ganglioglioma: a potentially malignant tumor?

Desmoplastic infantile ganglioglioma is a rare intracranial tumor of early childhood with a usually excellent prognosis despite malignant features both radiologically and histologically. We present the case of a desmoplastic infantile ganglioglioma with histologically highly anaplastic features and both intracerebral and pial metastases. After partial resection the tumor was rapidly progressive and new metastases appeared. A combination of vincristine and carboplatinum was used according to the Low Grade Glioma Protocol of the International Society of Pediatric Oncology, with a temporary good response. When histologically characterized by highly anaplastic features, it seems the biologic behavior of this tumor remains uncertain. The aggressive behavior and the responsiveness to chemotherapy in this case may challenge the belief in the benign nature of these rare tumors.

Mixed conventional and desmoplastic infantile ganglioglioma: an autopsied case with 6-year follow-up

We describe a case of desmoplastic infantile ganglioglioma (DIG) arising in the ventral diencephalon of a 3-1/2-month-old boy. On biopsy, the tumor featured a desmoplastic, S-100 protein and GFAP immunoreactive stromal element, as well as a variable spectrum of ganglion cells. Electron microscopy demonstrated astrocytes, and morphologically fibroblasts, as well as neurons containing 120-nm dense core granules. In addition, tubular structures composed of tightly apposed cells with features of astrocytes and of Schwann-like cells were also noted. Devoid of fibroblasts, the tubular structures were surrounded by a single basal lamina. At autopsy 6 years later, the multinodular, cystic mass had replaced the diencephalon, extended into both temporal lobes as well as the optic nerves, and showed marked leptomeningeal involvement. Microscopically, superficial portions of the tumor consisted of typical DIG, whereas deep, nondesmoplastic portions exhibited pattern variation ranging from pilocytic astrocytoma to ganglioglioma and gangliocytoma. There was also a minor element of small, 'primitive-appearing' neuroepithelial cells. Dysplastic ganglion cells variously reactive for neurofilament protein and synaptophysin were present throughout the tumor. Our study not only confirms DIG as a variant of ganglioglioma, one capable of slow growth, infiltration, and fatal progression but suggests that its differentiating potential includes elements of both the central and peripheral nervous systems. If so, their derivation may be from multipotential cells of the neural plate.

[Infantile desmoplastic ganglioglioma: a clinical, histopathological and epidemiological study of five cases]

Infantile desmoplastic gangliogliomas are rare tumors of the central nervous system, composed by a mixture of glial and neuronal cells and a fibrous stroma, which affect mainly young patients and arise from the surface of the cerebral hemispheres. We present five cases of infantile desmoplastic ganglioglioma: three were male and two were female. The ages ranged from three months and seven years (mean 2.62 years). The symptoms reflected the growth and topography of the tumors affecting the parietal (n = 3), parieto-occipital (n = 1), occipital (n = 1) lobes. Immunohistochemistry was performed in two cases with similar results to those reported in the literature.

Central nervous system neoplasms: indications for electron microscopy

Diagnostic dilemmas of biopsy specimens in the central nervous system (CNS) tumors are often the result of multiple factors, including fixation artifact, biopsy size, lack of immunohistochemical techniques to distinguish cell types, and unawareness of rare entities. Correct diagnosis and confirmation of diagnosis of primary CNS neoplasms is imperative and may require electron microscopic examination. In some instances, use of electron microscopy may be the only approach for accurate recognition of an entity. Although diagnostic electron microscopy is expensive and cost cutting is encouraged in today's practice of medicine, cost must be weighed against the consequences of even 1 patient developing CNS treatment-related necrosis or a radiation-induced neoplasm secondary to misdiagnosis of a benign entity. This study reviews the ultrastructural differences of three groups of diagnostically difficult CNS lesions: clear cell neoplasms (ependymoma, oligodendroglioma, central neurocytoma), rare entities containing astrocytes invested by a basal lamina (pleomorphic xanthoastrocytoma, the desmoplastic neuroepithelial tumors of infancy), and benign entities characterized by transitional cell forms (subependymoma, subependymal giant cell astrocytoma).

Desmoplastic low grade astrocytoma: a case report and review of literature

A 7-year-old girl presented with focal seizures without symptoms of raised intracranial tension. Routine histological, immunocytochemical and ultrastructural methods revealed a desmoplastic low grade cerebral astrocytoma. Follow up for 2 years after biopsy did not show recruitment of neurological symptoms or signs. Biphasic tumours containing glial and mesenchymal elements have been described in the literature under various diagnostic headings. As the histologically benign variants of mixed glial and mesenchymal tumours appear to have a good prognosis, identification of these as separate entities seems imperative. With a review of literature we propose a pathological classification of mixed glial and mesenchymal tumours.

Desmoplastic infantile ganglioglioma: CT and MRI features

We present three cases of desmoplastic infantile ganglioglioma in patients admitted to our institution in the past 8 years. CT and MR findings are discussed. Typically, these lesions are located in the frontal and parietal lobes, appearing as cystic tumors with a solid cortical component within the cerebrum, which enhances intensely, and moderate surrounding edema.

Clinical, radiological and histological findings in desmoplastic infantile ganglioglioma

The clinical course and radiological and histological findings in a 30-month-old boy suffering from desmoplastic infantile ganglioglioma are reported. The child's development was normal until a series of complex partial seizures occurred at the age of 7 months. Cranial computed tomography and magnetic resonance imaging revealed a cystic mass with intensive ring-shaped contrast enhancement in the right temporal fossa without shift of intracranial structures. Histologically, the firm, grayish tumor showed an enormous amount of connective tissue, cystic areas, and some mitoses. Glial and neuronal cell lines were identified by immunocytochemical methods. Eighteen months after surgery the boy had developed well without any neurological dysfunction; no radiation or chemotherapy was given. For the first time a synopsis of radiological findings in this rare brain tumor is correlated with the results of multiple histological and immunocytochemical studies. Despite some malignant characteristics, the prognosis of this dysontogenetic brain tumor is good.

Desmoplastic infantile gangliogliomas: an approach to therapy

Desmoplastic infantile gangliogliomas are massive cystic tumors, typically occurring in the cerebral hemispheres of infants. They are remarkable pathologically for a prominent desmoplasia and, in some cases, for a cellular mitotically active component that can be readily interpreted as a malignant neoplasm. Four children less than 1 year of age were diagnosed with desmoplastic infantile gangliogliomas in the Pediatric Oncology Group infant brain tumor study (Protocol number 8633). All had been diagnosed by their respective institutions as having malignant tumors, i.e., Grade III astrocytoma, malignant meningioma, leptomeningeal fibrosarcoma, and gliosarcoma. All had increased intracranial pressure, and two had seizures. The tumors were extremely large, with one measuring 12 x 9 x 9 cm. None had evidence of metastatic disease. One patient had a gross total resection, and the other three had debulking procedures. All four children were treated with chemotherapy (cyclophosphamide, vincristine, cisplatinum, etoposide) for periods ranging from 12 to 24 months. Of those with postoperative measurable disease, one child had a complete response, one a partial response, and one had stable disease at the conclusion of chemotherapy. No child received radiation therapy. All children are alive with progression-free survivals after diagnosis of more than 36, 42, 48, and 60 months, respectively. Although desmoplastic infantile gangliomas are rare, recognition of this tumor type is essential because, despite their massive size and pathologically malignant appearance, they may have a relatively benign clinical course. If total surgical resection can be achieved, further therapy may not be indicated. In those patients in whom residual disease is present, chemotherapy appears to be an effective form of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Desmoplastic infantile ganglioglioma and desmoplastic cerebral astrocytoma of infancy

The desmoplastic infantile ganglioglioma and desmoplastic cerebral astrocytoma of infancy are rare neoplasms arising in the cerebral hemispheres within the first two years of life which are defined by a combination of distinctive clinicopathologic features. The tumours are massive, partially cystic and invariably occur in a supratentorial location. Involvement of multiple lobes is common with a predilection for frontoparietal areas. In one series of 22 desmoplastic infantile gangliogliomas, all patients presented between 2 and 24 months of age (mean = 6 months; median = 4 months) with a male to female ratio of 1.4:1. In the nine reported cases of the desmoplastic cerebral astrocytoma of infancy, all patients presented between 1.5 and 14 months of age (mean = 6.8 months; median = 6 months) with a male to female ratio 0.8:1. The hallmark feature of both neoplasms is an abundant and often dense desmoplasia, imparting a characteristic firmness to the neoplasms. In the desmoplastic infantile gangliogliomas, astroglial and neuronal tumour cells in addition to variable numbers of more primitive, mitotic cells comprise the neoplastic neuroepithelial populations. In contrast, the neuroepithelial component of the desmoplastic infantile astrocytomas is restricted to neoplastic astrocytes. Despite the large size, cellular pleomorphism and cellular atypia, prognosis following successful surgical resection in both types of tumours is quite favorable. The longest followup data is available for the desmoplastic infantile gangliogliomas. With the median interval of 8.7 years (range 1 to 14.5 years) following surgery for 14 patients in this series, there were no deaths due to tumour or any evidence of tumour recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Desmoplastic supratentorial neuroepithelial tumours of infancy

The clinicopathological features of two infants with desmoplastic supratentorial neuroepithelial tumours are described. The cases were similar to the 26 cases reported previously as desmoplastic infantile ganglioglioma and superficial cerebral astrocytoma attached to dura. Neuronal differentiation was absent on routine stains, but was immunohistochemically established. We review the literature and suggest classifying this clinicopathological entity by using a general designation such as desmoplastic supratentorial neuroepithelial tumours of infancy, a term which indicates the variability in the amount and lines of differentiation.

Gliofibroma: immunohistochemical analysis

A case of gliofibroma occurring in an adult patient as a large circumscribed supratentorial tumor is reported. The bimorphic pattern was substantiated and further analyzed by immunohistochemistry. Some evidence in favor of collagen production by mesenchymal and/or inflammatory cells leading to a progressive fibrous replacement of the glial cells in this particular tumor type is presented.