Cerebellar pleomorphic xanthoastrocytoma: case report and literature review

Pleomorphic xanthoastrocytoma in the posterior fossa: a case report with advanced neuroimaging findings

Pleomorphic xanthoastrocytoma (PXA) is a rare glioma usually occurring in children and young adults. It is a benign World Health Organization (WHO) grade II tumor that accounts for <1% of all astrocytomas. Its occurrence in the infratentorial compartment is rare, and the cerebellum is the most common of the unusual locations. Few case reports have described conventional imaging features of these tumors, but none has reported the advanced magnetic resonance (MR) neuroimaging features in dynamic susceptibility perfusion-weighted imaging (DSC-PWI), diffusion weighted-imaging (DWI) and MR spectroscopy. Therefore, the purpose of this study is to report a case of PXA in the cerebellum of a 28-year-old patient and discuss the MR advanced imaging characteristics compared to the more common PXA supratentorial type.

Demography, Pattern of Care, and Survival in Patients with Xanthoastrocytoma: A Systematic Review and Individual Patient Data Analysis of 325 Cases

Objectives Xanthoastrocytoma (XA) is a low-grade glial tumor seen in young adults and there is lack of robust data on treatment of this rare tumor. In this systematic review and individual patient's data analysis, we aimed to look into the demography, pattern of care, survival outcomes, and prognostic factors in patients with both Grade II and III XA. Methods A comprehensive search was conducted with the Medical Subject Heading terms: "Xanthoastrocytoma; Pleomorphic Xanthoastrocytoma; Anaplastic Xanthoastrocytoma; Xanthoastrocytoma AND treatment; and Anaplastic Xanthoastrocytoma AND survival" to find all possible publications. Results A total of 325 individual patients from a total of 138 publications pertaining to XA were retrieved. Median age of the entire cohort was 19 years. About 56.1% of the patients underwent a gross total resection (GTR) and 31.4% underwent a subtotal resection. Nearly, 76.6% of the patients had a Grade II tumor and adjuvant radiation was delivered in 27.4% of the patients. Estimated 2- and 5-year progression-free survival (PFS) were 68.5 and 51.2%, respectively. Age, grade, and extent of surgery were significant factors affecting PFS. Estimated 2- and 5-year overall survival (OS) was 88.8 and 78%, respectively. The median OS for Grade II and Grade III tumors were 209 and 49 months, respectively. Age and extent of surgery were significant factors affecting OS. Conclusion XA is a disease of young adults with favorable prognosis. Younger patients (<20 years), patients who undergo a GTR, and patients with a lower grade tumor have a better treatment outcome.

Suprasellar pleomorphic xanthoastrocytoma: A case report

Background:

Pleomorphic xanthoastrocytoma (PXA) is a rare form of astrocytic neoplasm most commonly found in children and young adults. This neoplasm, which is classified as a Grade II tumor by the World Health Organization classification of tumors of the central nervous system, carries a relatively favorable outcome. It is usually found supratentorially in cortical regions of the cerebral hemispheres, and as such, presenting symptoms are similar to other supratentorial cortical neoplasms; with seizures being a common initial symptom. Due to the rarity of this type of neoplasm, PXA arising elsewhere in the brain is often not included in the initial differential diagnosis.

Case Description:

This report presents an extremely rare patient with PXA arising in the suprasellar region who presented with progressive peripheral vision loss. Magnetic resonance imaging of the brain demonstrated a heterogeneous suprasellar mass with cystic and enhancing components initially; the most likely differential diagnosis was craniopharyngioma. The patient underwent endoscopic endonasal resection of the tumor. Microscopically, the tumor was consistent with a glial neoplasm with variable morphology. Based on these findings along with further immunohistochemical workup, the patient was diagnosed with a PXA arising in the suprasellar region. At the 1-year follow-up, the patient remained free of recurrence. Although rare PXA originating in other uncommon locations, such as the spinal cord, cerebellum, the ventricular system, and the pineal region have been previously described.

Conclusion:

Although rare, PXA should be included in the differential diagnosis for solid-cystic tumors arising in the suprasellar region in young adults.

Grade II Pleomorphic Xanthoastrocytoma; a meta-analysis of data from previously reported 167 cases

Pleomorphic Xanthoastrocytoma [PXA] is a rare low grade glial tumor commonly affecting young adults. We did this systematic review and meta-analysis to identify prognostic factors and optimal treatment in these patients. A thorough search of the PubMed, Google scholar was made to find all possible publications related to grade II PXA. A total of 167 patients from 89 articles were included in the analysis. Median age of the entire cohort was 20 years. Headache was the most common presentation in 49.1% of the patients followed by seizure in 27.9%. Temporal lobe was the most common location of the tumor. 63% patents underwent a gross total resection [GTR] and 26.7% underwent a sub total excision [STR]. Adjuvant radiation was given to 17.6% of patients. Median follow-up for the entire cohort was 33 months. Estimated median overall survival [OS] for the entire cohort was 209.0 months [96% CI: 149.7-268.3]. Estimated median progression free survival [PFS] was 48 months [95% CI: 31.9-64.0]. In univariate and multivariate analysis younger patients and patients who underwent a GTR had a significantly better survival outcome. Use of adjuvant therapy was not found to be a significant factor affecting PFS or OS. Radiotherapy was used in salvage treatment in 76.1% of the patients. Younger patients and patients who undergo a GTR, have better survival outcomes. There is inadequate evidence to recommend routine adjuvant radiation or chemotherapy in all patients with grade II PXA.

Intraventricular Anaplastic Pleomorphic Xanthoastrocytoma: Very Rare Localization and Early Recurrence of a Rare Tumor

We report a rare case of an adult, with no previous history of seizures, found to have a large intraventricular Anaplastic Pleomorphic Xanthoastrocytoma (APXA). To the best of our knowledge, this is only the second documented report of an APXA located within the ventricular system in an adult. The tumor was characterized by anaplastic features and necrosis without an elevated mitotic index, and it recurred shortly after a gross total surgical resection.

Pleomorphic Xanthoastrocytoma; Clinicopathological spectrum of An Intriguing neoplasm

Background & Objective:

Pleomorphic xanthoastrocytoma (PXA) is a rare primary WHO Grade II astrocytic tumor comprising of < 1% of all astrocytomas. It is generally benign and slow growing however disease progression and malignant transformation with anaplastic features have been infrequently reported. Our objective was to assess clinicopathological characteristics of this rare tumor at our center.

Methods:

A retrospective study was conducted at Aga Khan University Hospital from January 1992 till January 2016. Data was entered on a proforma including patient demographics, clinical features, tumor location, histological features and follow-up, where available.

Results:

Forty Seven cases of PXA were retrieved during the study period. The mean age was 23.8 years (SD=15.1) and median age was 19 years. The most frequent symptom was head ache (n=31). Male were more frequently affected (n=26). The commonest location was temporal lobe. On microscopic examination, tumors were pleomorphic without mitoses or necrosis, however two cases showed increased mitotic activity, and one case revealed associated gliosarcoma. Follow-up of only 29 cases was available for a period ranging between 2 and 184 months (85 months +/- 56 months). Outcome was good in 27 patients with the last follow up showing no radiographic or clinical evidence of tumor recurrence.

Conclusions:

PXA is an infrequent tumor in our population also, with less than 50 cases identified in two decades study period. Due to its rarity and its bizarre histomorphology, it should be diagnosed correctly, as it has got better prognosis than other astrocytic tumors.

An Infratentorial Pure Pleomorphic Xanthoastrocytoma Arising from Middle Cerebellar Peduncle: A Rare Location of an Uncommon Tumor

BACKGROUND

Pleomorphic xanthoastrocytomas are rare tumors of glial origin comprising <1% of all astrocytic tumors of brain. These tumors are rare in the infratentorial compartment and were not known to arise from the middle cerebellar peduncle.

CASE DESCRIPTION

We discuss the case of a 16-year-boy who presented with altered sensorium and features of increased intracranial pressure and was found to have a 4 × 4 × 3 cm mass arising from the middle cerebellar peduncle.

CONCLUSION

We also discuss the histopathologic features of these tumors suggesting their resemblance to other maldevelopmental tumors, the rarity of pure World Health Organization grade II pleomorphic xanthoastrocytoma in the infratentorial compartment, as well as the appropriate management.

If it is Not a Glioblastoma, Then What is it? A Differential Diagnostic Review

As its historical name glioblastoma multiforme implies, glioblastoma is a histologically diverse, World Health Organization grade IV astrocytic neoplasm. In spite of its simple definition of presence of vascular proliferation and/or necrosis in a diffuse astrocytoma, the wide variety of cytohistomorphologic appearances overlap with many other neoplastic or non-neoplastic lesions. Here, after a brief review of glioblastoma is provided, the differential diagnostic possibilities with an emphasis on mimics and pitfalls are discussed. To provide an approach applicable to diagnostic practice, these discussions are grouped arbitrarily according to general malignant appearance such as pleomorphic xanthoastrocytoma and ganglioglioma, especially their anaplastic versions, and cellular features such as small cell and epithelioid glioblastoma. Some non-neoplastic lesions that can potentially be mistaken for glioblastoma under certain circumstances are also briefly mentioned. Additional studies, including immunohistochemistry and molecular markers, are included where applicable. Otherwise, exhaustive review of these individual entities, including their epidemiology and molecular biology, is outside the scope of this discussion.

BRAF-Mutated Pleomorphic Xanthoastrocytoma of the Spinal Cord with Eventual Anaplastic Transformation

BACKGROUND

Pleomorphic xanthoastrocytoma (PXA) is an uncommon, primary neoplasm of the central nervous system with a relatively favorable prognosis. Most patients are managed with surgery alone and experience significant long-term survival. PXAs occur most commonly along the superficial surfaces of the temporal lobes. Although these tumors may occur in other regions of the brain, their origin within the spinal cord is rare, and it is unclear whether spinal cord PXAs should be managed differently from their intracranial counterparts.

CASE DESCRIPTION

We describe a 31-year-old patient with a PXA of spinal cord origin who despite surgery, radiation, and multiple chemotherapy regimens experienced anaplastic transformation of his tumor and died of extensive leptomeningeal progression.

CONCLUSIONS

To our knowledge, our patient represents the seventh reported case of PXA of the spinal cord but is the first described to have a BRAF mutation. Specifically, both the initial and recurrent tumors of the patient showed the same BRAF V600E mutation, which refutes previous suggestions that BRAF mutations may be limited to intracranial PXAs and also shows that BRAF mutations may occur earlier in PXA tumorigenesis.

CNS and spinal tumors

Primary CNS tumors consist of a diverse group of neoplasms originating from various cell types in the CNS. Brain tumors are the most common solid malignancy in children under the age of 15 years and the second leading cause of cancer death after leukemia. The most common brain neoplasms in children differ consistently from those in older age groups. Pediatric brain tumors demonstrate distinct patterns of occurrence and biologic behavior according to sex, age, and race. This chapter highlights the imaging features of the most common tumors that affect the child's CNS (brain and spinal cord).

Atypical pleomorphic neoplasms of the pineal gland: Case report and review of the literature

Background:

Pineal region tumors are rare and diverse. Among them exist reports of pleomorphic xanthroastrocytoma (PXA) and pleomorphic granular cell astrocytoma (PGCA) of the pineal gland. These related tumors are remarkably similar sharing pleomorphic histologic features with only minor immunohistochemical and ultrastructural differences.

Case Description:

We present a case of a 42-year old right-handed woman presented with a longstanding history of migraine headaches which had worsened over the two months leading up to her hospitalization. MRI revealed a 1.7 × 1.3 × 1.6 cm intensely enhancing lesion originating in the pineal gland. The tumor closely resembled PGCA but did not strictly fit the diagnostic requirements of either PGCA or PXA.

Conclusion:

The present case highlights the exotic nature of pineal region tumors with pleomorphic cell histology. Given the diverse range of tumors encountered in the pineal region, pathological confirmation is mandatory. Favorable clinical outcomes demonstrate that surgical resection alone can yield excellent long-term results for tumors falling within the spectrum of pleomorphic lesions of the pineal gland.

Pleomorphic Xanthoastrocytoma: Natural History and Long-Term Follow-Up

Prognostic significance of histological anaplasia and BRAF V600E mutation were retrospectively evaluated in 74 patients with pleomorphic xanthoastrocytoma (PXA). Median age at diagnosis was 21.5 years (31 pediatric, 43 adult) and median follow-up 7.6 years. Anaplasia (PXA-AF), defined as mitotic index ≥ 5/10 HPF and/or presence of necrosis, was present in 33 cases. BRAF V600E mutation was detected in 39 (of 60) cases by immunohistochemical and/or molecular analysis, all negative for IDH1 (R132H). Mitotic index ≥ 5/10 HPF and necrosis were associated with decreased overall survival (OS; P = 0.0005 and P = 0.0002, respectively). In all cases except two, necrosis was associated with mitotic index ≥ 5/10 HPF. Patients with BRAF V600E mutant tumors had significantly longer OS compared with those without BRAF V600E mutation (P = 0.02). PXA-AF patients, regardless of age, had significantly shorter OS compared with those without (P = 0.0003). Recurrence-free survival was significantly shorter for adult PXA-AF patients (P = 0.047) only. Patients who either recurred or died ≤ 3 years from diagnosis were more likely to have had either PXA-AF at first diagnosis (P = 0.008) or undergone a non-gross total resection procedure (P = 0.004) as compared with patients who did not. This study provides further evidence that PXA-AF behaves more aggressively than PXA and may qualify for WHO grade III "anaplastic" designation.

Prognostic factors and therapeutic outcomes in 22 patients with pleomorphic xanthoastrocytoma

OBJECTIVE

Pleomorphic xanthoastrocytoma (PXA) is a rare primary low-grade astrocytic tumor classified as WHO II. It is generally benign, but disease progression and malignant transformation have been reported. Prognostic factors for PXA and optimal therapies are not well known.

METHODS

The study period was January 2000 to March 2012. Data on MR findings, histology, surgical extents and adjuvant therapies were reviewed in twenty-two patients diagnosed with PXA.

RESULTS

The frequent symptoms of PXA included seizures, headaches and neurologic deficits. Tumors were most common in the temporal lobe followed by frontal, parietal and occipital lobes. One patient who died from immediate post-operative complications was excluded from the statistical analysis. Of the remaining 21 patients, 3 (14%) died and 7 (33%) showed disease progression. Atypical tumor location (p<0.001), peritumoral edema (p=0.022) and large tumor size (p=0.048) were correlated with disease progression, however, Ki-67 index and necrosis were not statistically significant. Disease progression occurred in three (21%) of 14 patients who underwent GTR, compared with 4 (57%) of 7 patients who did not undergo GTR, however, it was not statistically significant. Ten patients received adjuvant radiotherapy and the tumors were controlled in 5 of these patients.

CONCLUSION

The prognosis for PXA is good; in our patients overall survival was 84%, and event-free survival was 59% at 3 years. Atypical tumor location, peritumoral edema and large tumor size are significantly correlated with disease progression. GTR may provide prolonged disease control, and adjuvant radiotherapy may be beneficial, but further study is needed.

Pleomorphic xanthoastrocytoma: long-term results of surgical treatment and analysis of prognostic factors

BACKGROUND

Pleomorphic Xanthoastrocytoma (PXA) is a rare brain tumour, most commonly affecting children and young adults. To date, only few data regarding the long-term follow-up of these patients after surgery are available. The aim of this study is to describe our single-institution experience in the surgical management of this particular glioma over a period of over 18 years.

METHODS

We performed a retrospective review of all cases of PXA (40 patients) operated upon at the Department of Neurosurgery of Verona, Italy, between 1990 and 2008. The impact of clinical, radiological, surgical and histological factors on overall survival (OS) and progression-free survival (PFS) was analysed by means of univariate and multivariate models.

FINDINGS

We achieved a gross total resection (GTR) in 65% of patients. Histological diagnosis was of grade II in 80%; anaplastic features were present in the remaining 20%. Adjuvant treatment, radiotherapy or chemo-radiotherapy, was administered in 40% of the cases. Median follow-up was 74 months. OS at 5- and 10 years was 76.32% and 68.24%, respectively. PFS at 5- and 10 years was 71% and 58%, respectively. In the multivariate model, histological grade, extent of resection and age at diagnosis (≤ 30 years vs > 30 years) were the only independent prognostic factors for both OS and PFS.

CONCLUSIONS

Our retrospective long-term study confirms the relatively favourable prognosis associated with PXA. Young patients with a low-grade tumour (WHO grade II) who underwent GTR carry the longest OS and PFS.

Pleomorphic xanthoastrocytoma: magnetic resonance imaging findings in a series of cases with histopathological confirmation

Pleomorphic xanthoastrocytoma (PXA) is a rare glioma. This paper aimed to analyze magnetic resonance imaging (MRI) characteristics in a series of patients diagnosed with PXA. We analyzed MRI findings in 9 patients with histopathologic diagnosis of PXA in our department over the last 12 years. The mean age of patients was 27.3 years. Cortical location was observed in all cases. The lesion imaging was solid-cystic in six cases. In eight cases, the solid component presented hypo or isointense on T1 and iso or hyperintense on T2. Contrast enhancement in the solid component was observed in eight cases. The observed imaging pattern of PXA was superficial location with leptomeningeal involvement, solid-cystic pattern and contrast enhancement in the solid component. We should consider that the association between PXA and other cortical tumors may occur, particularly, with gangliogliomas, which tend to be the main differential diagnosis in MRI.

Establishment of a primary pleomorphic xanthoastrocytoma cell line: in vitro responsiveness to some chemotherapeutics

BACKGROUND

Anaplastic pleomorphic xanthoastrocytoma is an aggressively growing, malignant, and eventually fatal tumor of the central nervous system. Testing chemotherapeutic drug sensitivity under in vitro conditions would be a useful strategy to determine sensitive or resistant drugs for fatal brain cancers.

OBJECTIVE

To establish primary cell cultures of excised tumor tissue from pleomorphic xanthoastrocytoma-bearing patients and to test their sensitivity against various anticancer chemotherapy drugs.

METHODS

Prepared suspensions of the excised tumor tissue from a patient who had a recurrent grade 3 pleomorphic xanthoastrocytoma was cultured in culture dishes until cells began to grow. Immunofluorescent and immunohistochemical visualizations were performed using confocal and light microscopy. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in comparison with ³H-thymidine incorporation assay was used to test cellular toxicity of several anticancer drugs.

RESULTS

We established vigorously growing primary cells of the tumor. Drug sensitivity testing was conducted successfully.

CONCLUSION

Primary cell cultures of surgically removed tumor tissues may be useful in studies of cancer biology and chemotherapeutic drug sensitivity for recurrent malignant brain tumors, particularly for anaplastic pleomorphic xanthoastrocytoma.

Patterns of care and outcomes of patients with pleomorphic xanthoastrocytoma: a SEER analysis

To study the clinical characteristics, treatment approach and outcome of pleomorphic xanthoastrocytoma (PXA), patients were identified using the National Cancer Intitute's Surveillance, Epidemiology, and End Results (SEER) database. A total of 214 patients were identified with PXA using the November 2010 submission. Patient demographics, tumor characteristics, extent of surgical resection, the use of radiotherapy, and overall survival were evaluated. Overall survival for PXA was then compared to that of pilocytic astrocytoma, oligodendroglioma, ependymom and glioblastoma also using the SEER database. Kaplan-Meier, univariate and multivariate analyses were performed. The majority of patients were found to be young adults with the most common tumor location being temporal lobe. Surgery was performed on most (95 %) patients, while 25 % of patients received radiation therapy. Five and 10 year overall survival rates were 75 and 67 %, respectively. Grade was only available for a limited number of patients but appeared to affect prognosis. Patients with grade IV tumors had a median overall survival of 45 months, whereas median survival was not reached for grade I-III patients. On multivariate analysis, male gender and increasing age were associated with worse overall survival (p values 0.05 and <0.006, respectively). Extent of resection trended towards significance in favor of gross total resection. PXA is a rare diagnosis that affects young adults. Surgical resection is the primary modality of treatment with an overall good prognosis. Elderly patients, those with higher grade disease and patients with incomplete resections may have a worse prognosis. The role of radiation therapy for PXA remains unclear but is more often used for patients with high grade tumors. Compared to other common brain tumors, PXA's appear to fare worse than pilocytic astrocytoma and oligodendroglioma, especially in younger patients. However, even high grade PXA patients have significantly better overall survival compared to glioblastoma.

Malignant potential of pleomorphic xanthoastrocytoma

Pleomorphic xanthoastrocytoma (PXA) is a low-grade astrocytic tumour that occasionally progresses to a higher grade. We have extensively reviewed the literature on the potential for malignant transformation of PXA. An illustrative case of a PXA transforming to glioblastoma multiforme is presented.

Pigmented pleomorphic xanthoastrocytoma: a rare variant and literature review

A 16-year-old male teenager presented with seizure and loss of consciousness for 20 min. Magnetic resonance imaging demonstrated a mass occupying the right medial temporal lobe. Histological examination revealed a non-pigmented area with spindle-shaped and large xanthomatous pleomorphic cells and a pigmented region with pigmented neoplastic cells with fascicular arrangement. Immunohistochemical studies showed the tumor was positive for GFAP and low index of Ki-67. Considering the patient's history, clinical data and pathological findings, we rendered a rare variant named pigmented pleomorphic xanthoastrocytoma.

Glycogen-rich pleomorphic xanthoastrocytoma with clear-cell features: confirmatory report of a rare variant with implications for differential diagnosis

Central nervous system space-occupying lesions with clear-cell features encompass a nosologically heterogeneous array, ranging from reactive histiocytic proliferations to neuroepithelial or meningothelial neoplasms of various grades and to metastases. In the face of such differential diagnostic breadth, recognizing cytoplasmic lucency as part of the morphological spectrum of some low grade gliomas will directly have an impact on patient care. We describe a prevailing clear-cell change in an epileptogenic left temporal pleomorphic xanthoastrocytoma surgically resected from a 36-year-old man. Mostly subarachnoid and focally calcified, the tumor was composed of fascicles of moderately atypical spindle cells with optically lucent cytoplasm that tended to intermingle with a desmoplastic mesh of reticulin fibers. Immunohistochemically, coexpression of S100 protein, vimentin, GFAP, and CD34 was noted. Conversely, neither punctate staining for EMA nor positivity for CD68 was seen. Mitotic activity was absent, and the MIB1 labeling index was 2-3% on average. Diastase-sensitive PAS-positive granula indicated clear-cell change to proceed from glycogen storage. Electron microscopy showed tumor cell cytoplasm to be largely obliterated by non-lysosomal-bound pools of glycogen, while hardly any fat vacuole was encountered. Neither ependymal-derived organelles nor annular lamellae suggesting oligodendroglial differentiation were detected. The latter differential diagnosis was further invalidated by lack of codeletion of chromosomal regions 1p36 and 19q13 on molecular genetic testing. By significantly interfering with pattern recognition as an implicit approach in histopathology, clear-cell change in pleomorphic xanthoastrocytoma is likely to suspend its status as a "classic", and to prompt more deductive differential diagnostic strategies to exclude look-alikes, especially clear-cell ependymoma and oligodendroglioma.

Intraventricular pleomorphic xanthoastrocytoma with anaplastic features

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor that usually occurs in the superficial cerebral hemispheres of children and young adults and has a relatively favorable prognosis. We report an unusual case of supratentorial, intraventricular tumor in a 52-year-old man. The tumor was composed of pleomorphic cells, including giant cells, most of which were multinucleated, and small cells. In addition, frequent xanthic changes in the cytoplasm of the tumor cells, and widespread reticulin deposits and lymphocytic infiltrates in the stroma were characteristic features. Large areas of necrosis were also evident. However, mitotic figures were rare (1-2 mitoses per 10 high-power fields). Many tumor cells were positive for GFAP, and a number were positive for neurofilament protein and synaptophysin, indicating their neuronal differentiation. In addition, occasional tumor cells were positive for CD34. p53 protein was entirely negative in the tumor cells. In diagnosing this tumor histopathologically, differentiation between PXA and giant cell glioblastoma (GCG), a rare variant of glioblastoma, was problematic. However, considering the overall histopathological picture, a final diagnosis of PXA with anaplastic features was made. The present case indicates that PXA can occur as an intraventricular tumor, and suggests that in some instances, it would be very difficult to differentiate PXA and GCG histopathologically.

Diagnosis of childhood astrocytomas

BACKGROUND

Astrocytomas are the most common brain tumours, accounting for 28 - 50% of all primary CNS tumours. Diagnosis of CNS tumours remains difficult because the varied and nonspecific presentations of CNS tumours in childhood. Objectives/method: The clinical presentations of CNS astrocytomas vary with their sites of location; therefore, a period of uncertainty often precedes diagnosis, and approximately 42% of patients with an intracranial process make several visits to various physicians between the onset and diagnosis. However, on clinical suspicion of a brain tumour, a wide range of neuroimaging techniques may be used to assess the diagnosis of paediatric brain lesions. In this review the authors, for ease of presentation, describe the clinical presentations of supratentorial, infratentorial and spinal cord astrocytomas as well as their radiological and pathological features, and discuss their differential diagnoses.

RESULTS/CONCLUSIONS

Understanding and mastering the numerous imaging features of several subtypes of primary brain tumours affecting children, in addition to radiological features of non-tumoural disorders, remains a significant challenge and demands increased awareness of the paediatric brain diseases.

Primary anaplastic pleomorphic xanthoastrocytoma with widespread neuroaxis dissemination at diagnosis--a pediatric case report and review of the literature

We report a 5 year-old boy with primary anaplastic pleomorphic xanthoastrocytoma (PXA) with whole neuroaxis dissemination at diagnosis who experienced the sudden onset of generalized convulsion. Head- and spinal magnetic resonance imaging (MRI) showed widespread gadolinium (Gd)-enhanced lesions extending to the bilateral frontal- and medial temporal lobes and the spinal cord. Subsequent MRI study demonstrated that the lesion size increased without any neurological deterioration. Under a histopathologic diagnosis of anaplastic PXA he underwent adjuvant chemotherapy consisting of 12 cycles of carboplatin and vincristine. The patient is alive without any neurological deficits; follow-up MRI showed that the lesions remained stable during 18 months of chemotherapy. We report a very rare pediatric case of primary anaplastic PXA with dissemination involving the entire neuroaxis at the time of diagnosis.

A 16-year-old male with a cerebellar mass

A 16-year-old male presented to an emergency room after falling on his head while inebriated. The patient had only a history of recent fatigue and demonstrated no focal neurological deficit. MRI revealed a cystic and solid, enhancing midline cerebellar lesion. A suboccipital craniotomy was performed. Histologically, the mass showed large bizarre cells arranged in sheets with admixed small lymphocytes. The pleomorphic population had ample glassy eosinophilic cytoplasm and intranuclear inclusions. An infiltrating component resembling diffuse astrocytoma could be found in areas. Rosenthal fibers were particularly abundant in the areas of infiltrating glioma. Mitotic activity was very low, and necrosis was absent. Reticulin fibers between individual cells were focally abundant. Glial fibrillary acidic protein and vimentin were strongly expressed in many cells, while synaptophysin and neurofilament protein were not. Ki-67 showed a very low proliferation index. The pathologic diagnosis was pleomorphic xanthoastrocytoma (PXA) of the cerebellum. PXA is a diagnosis typically regarded as a superficial meningocerebral neoplasm. This case is one of sixteen cerebellar PXAs reported in the literature.