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.     

Spinal imaging in intracranial primary pleomorphic xanthoastrocytoma with anaplastic features

We present a patient with an intracranial primary pleomorphic xanthoastrocytoma (PXA) with anaplastic features that recurred repeatedly after surgery. Late in the course, radiological follow-up revealed an unresectable spinal tumor. Very few patients with PXA associated with a spinal tumor have been reported. Earlier detection of the spinal lesion would have potentially improved the therapeutic options for the patient.     

Primary spinal pleomorphic xanthoastrocytoma

Pleomorphic xanthochromic astrocytoma primarily of the spinal cord is a rare entity. The case is possibly the fifth such report. Complete surgical excision is the essential requirement for good survival. In the absence of any clearly laid down protocols of adjuvant treatment, anecdotal reports support treatment with chemotherapy alone or both chemotherapy and radiotherapy.     

Cerebral anaplastic pleomorphic xanthoastrocytoma with meningeal dissemination at first presentation

Introduction Pleomorphic xanthoastrocytoma (PXA) is a rare brain glial tumour found in young patients. Most cases are reported as evolving low-grade neoplasms associated with a long survival after complete surgical resection. Some PXAs, however, can demonstrate secondary malignant transformation or progress with a short survival. Anaplastic histological features at first presentation or secondary meningeal dissemination have rarely been reported.Case report We describe the case of a cerebral PXA in a 7-year-old girl presenting with anaplastic histological features and craniospinal meningeal dissemination that progressed rapidly with a poor outcome.     

Pediatric cerebellar pleomorphic xanthoastrocytoma with anaplastic features: a case of long-term survival after multimodality therapy

Case report A 4-year-old girl had a large midline cerebellar solid and cystic mass partially attached to the meninges. The original diagnosis was glioblastoma multiforme and she was treated by a gross-total surgical resection followed by chemotherapy and radiation theraphy to the posterior fossa during the ensuing 14 months. She has received no further theraphy and appears to be doing well 12 years later. This unusual favorable clinical outcome prompted our review of this case.Methods Additional special stains and immunocytochemistry were performed on the paraffin embedded tumor sections.Results We have confirmed the original histopathological observations of hypercellularity and focal nuclear pleomorphism, atypical mitoses, vascular hyperplasia, as well as focal necrosis. However, the additional stains revealed that the tumor is a relatively well-circumscribed meningeal-based astrocytic tumor (positive for GFAP) with extensive reticulin deposit and focal neuronal differentiation (positive for synaptophysin). A Ki67 labeling index is generally very low, but is positive in up to 5-10% of tumor cells focally. In the light of the favorable clinical outcome and the overall histological features, this tumor may be best reclassified as a rare example of cerebellar pleomorphic xanthoastrocytoma with foci of anaplasia.     

间变型多形性黄色瘤型星形细胞瘤

目的报道1例男性间变型多形性黄色瘤型星形细胞瘤患儿的临床资料,探讨其临床病理学、免疫表型、基因突变特征,以及诊断与鉴别诊断要点。方法与结果男性患儿,11岁,头痛伴左上肢无力15 d。头部CT和MRI显示右侧颞叶和基底节区巨大占位性病变,提示胶质瘤。遂行右侧颞叶和基底节区占位性病变切除术,术中可见肿瘤呈囊实性,实性部分呈灰黄色,质地柔软,血供丰富,无包膜,与周围组织界限清晰。术中冰冻病理学提示低级别胶质瘤,遂分块全切除肿瘤。组织学形态观察,肿瘤细胞呈多形性,由梭形和圆形星形胶质细胞以及单核细胞和多核瘤巨细胞组成,核分裂象罕见;局部可见较成熟的神经元或节细胞分化成分,伴淋巴细胞浸润;部分区域肿瘤细胞呈间变特征,细胞密度增加,异型性明显,以圆形和梭形细胞为主,核分裂象5个/10高倍视野,血管内皮细胞增生,伴血管周围假"菊形团"样结构,局灶性坏死。免疫组织化学染色,低级别肿瘤细胞胞质表达胶质纤维酸性蛋白(GFAP)和BRAF V600E、胞质和胞核表达S-100蛋白、胞膜表达CD34,少数肿瘤细胞胞质表达突触素和非磷酸化神经丝重链SMI-32,Ki-67抗原标记指数为3%;低级别和高级别肿瘤细胞胞核均表达P53;高级别肿瘤细胞胞质表达GFAP和BRAF V600E,Ki-67抗原标记指数为30%。网织纤维染色可见肿瘤细胞周围包绕基底膜样物质。基因检测显示,低级别和高级别肿瘤均存在BRAF V600E杂合突变。结论2016年世界卫生组织中枢神经系统肿瘤分类将间变型多形性黄色瘤型星形细胞瘤定义为核分裂象5个/10高倍视野,属WHOⅢ级,预后较WHOⅡ级多形性黄色瘤型星形细胞瘤差。鉴别诊断主要包括胶质母细胞瘤、毛细胞型星形细胞瘤和节细胞胶质瘤,尽管上述肿瘤临床表现、组织学形态、免疫表型和基因突变有重叠,但生物学行为、治疗及预后各异。     

Anaplastic pleomorphic xanthoastrocytoma

A case of anaplastic pleomorphic xanthoastrocytoma (PXA) in a 9-year-old girl is reported. Histological features of PXAs are cellular pleomorphism of GFAP-positive cells, with intracytoplasmic lipidic vacuoles and a reticulin network, bizarre giant cells, low mitotic activity, and lack of necrosis and of endothelial vascular proliferations. These tumors are generally reported to have a favorable postoperative course. In our case, a poor clinical prognosis and spread of the illness through the CSF was observed. Immunohistochemical features of the tumor, which were histologically anaplastic in nature, were analyzed. There were small foci of necrosis in the sections of the material obtained at the first operation and extensive necrosis in that from the second operation, although the patient had not received radiotherapy between the operations. The presence of necrosis in PXA is an uncommon and significant feature. It predicts the poor prognosis seen in this case, and therefore this report strongly supports the notion that necrosis should automatically exclude a tumor from the PXA category. The histological grade was evaluated as grade 3 (according to the WHO classification). Received: 21 April 1996 Revised: 2 July 1996     

脑多形性黄色星形细胞瘤的临床与MRI特征分析

目的 探讨多形性黄色星形细胞瘤(pleomorphic xanthoastrocytoma,PXA)临床病理及MRI表现.方法 回顾性分析经手术病理证实的13例PXA患者的MRI及临床资料,所有患者均行MRI平扫及增强扫描检查.结果①临床表现:12例主诉头晕、头痛或癫痫;1例为偶然发现.②手术病理:病变发生于额叶6例,颞叶3例,枕叶1例,小脑1例,丘脑1例,鞍区1例.肿瘤合并大小不等囊变.镜下12例由多形性巨细胞、梭形细胞及泡沫细胞构成,WHO Ⅱ级.1例异形性较明显的多角形细胞和梭形细胞组成,伴间变特点.免疫组化:所有病例胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)均阳性;波形蛋白阳性12例,阴性1例.③MRI表现:MRI清楚显示病变的部位和形态、信号特点.13例患者中,11例发生于皮层或浅表部位;另2例分别发生在丘脑及右侧额叶深部;形态上表现为囊性4例、囊实性4例和实性5例.病变实性部分T1WI以稍低或等信号为主,T2WI以稍高信号为主.囊性部分T1WI低信号,T2WI高信号;实性部分明显强化6例,轻中度强化6例,不强化1例;囊性及囊实性病例中,囊壁明显强化5例,轻度强化2例,无明确强化1例.4例出现病变邻近脑膜轻度强化.结论 PXA临床表现独特,MRI能够良好显示其形态及组织学特点,具有重要诊断和鉴别诊断价值.     

Temporal pleomorphic xanthoastrocytoma with glycogen accumulation--case report

Pleomorphic xanthoastrocytoma (PXA) is a rare superficial glioma that predominates in the young and has good prognosis. A long history of repeated seizures is commonly associated with PXA, which is frequently observed in neuroimaging scans as a solid-cystic, contrast-enhancing lesion. We report a case in which PXA diagnosis was favored by its histological features, such as pleomorphic multinucleated giant cells, with disproportionately few mitoses and necrotic areas. An eye-catching feature was widespread, pale-staining, circumscribed deposits in the cytoplasm of tumor cells, which turned out to be glycogen upon histochemical and electron-microscopical examination. The stored material was strongly PAS-positive and digested by diastase, and had a finely granular ultrastructural appearance. No evidence of lipid droplets was found on oil-red-O staining. The tumor was immunoreactive for glial fibrillary acidic protein and vimentin. Many cells were positive for CD34 on the external membrane, a feature which has been described in chronic CNS lesions associated with epilepsy. Intracytoplasmic immunostaining for EGFR was observed in most tumor cells, which might have favored neoplastic proliferation. Nuclear immunolabeling for p53 protein was rare and does not support a major role for p53 mutation in PXA tumorigenesis. Intracellular accumulation of glycogen in glial tumors is uncommon and may originate from abnormalities in carbohydrate metabolic pathways.     

An anaplastic pleomorphic xanthoastrocytoma with periventricular extension: An autopsy case report and review of the literature

Pleomorphic xanthoastrocytomas (PXAs) are rare low-grade astrocytic tumors that typically present as superficial nodular cystic tumors of the cerebrum attached to the leptomeninx. Histologically, they are pleomorphic, hypercellular glial neoplasms. Despite the presence of microscopic pleomorphism, patients’ postoperative prognosis is generally good. Anaplastic PXAs (APXAs) have a high mitotic index and patients with APXAs have a worse prognosis than patients with PXAs. Here, we report an autopsy case of APXA initially diagnosed as PXA. After gross total resection, the tumor recurred and was diagnosed as an APXA; thereafter, the patient died. An autopsy revealed that the tumor had relapsed at the primary site and had spread to the leptomeningeal space while concurrently invading the cerebrum including the periventricular area forming multifocal lesions. The histological findings of the autopsy were similar to those for epithelioid glioblastoma (EGBM) and small cell glioblastoma (SCGBM). In particular, the periventricular area with multifocal lesions was composed of SCGBM-like cells. It has been shown that multifocal lesions are frequently identified in patients with SCGBM. This is the first histopathologically confirmed case of APXA-related tumor presenting with periventricular extension and multifocal lesion formation. The periventricular extension might be a feature of PXAs and APXAs. However, suspected periventricular spread on imaging in past cases of PXAs and APXAs might instead represent the malignant transformation of these tumors to glioblastoma-like high-grade tumors, which often show SCGBM-like histological patterns.     

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.     

多形性黄色星形细胞瘤临床病理分析

目的探讨多形性黄色星形细胞瘤(PXA)的临床病理学特征、诊断与鉴别诊断、发病机制、治疗及预后。方法对1例PXA进行临床影像学与病理分析及免疫组化研究。结果患者男性,25岁,因反复抽搐8年入院。头颅MRI显示左侧海马斑片状异常信号影,直径约0.9cm。镜下肿瘤细胞呈多形性,包括梭形、单核样细胞及多核瘤巨细胞等,这些细胞被网状纤维包绕在其中,间质可见嗜酸性颗粒小体。有的瘤细胞胞浆内含有脂滴,灶区可见血管周淋巴细胞浸润。但不见坏死、病理性核分裂及血管内皮细胞增生。免疫组化染色肿瘤细胞表达GFAP、Viminten、S-100和CD34,Ki-67增殖指数小于2%,EMA、Neu N、NF和CD163染色为阴性。结论 PXA是一种主要发生于儿童及青少年罕见的致痫性星形细胞瘤,组织学分级为WHO II级。若能手术完整切除,则预后良好。但是原发性具有间变特征的PXA和复发性伴有恶性转化的PXA的预后却是相当差的,因为他们都属于高级别的胶质瘤。     

A case of pleomorphic xanthoastrocytoma

A case of pleomorphic xanthoastrocytoma (Kepes) is reported. This patient was a 12-year-old boy with a history of convulsive seizure. Neurological examination on admission showed no abnormality. Plain CT scan revealed a well defined low density area with calcification in the right frontal lobe. A part of peripheral portion of low density area were well enhanced with contrast media. At operation, there was a cyst containing xanthochromic fluid in the right frontal lobe. A part of cyst well near the cerebral surface was reddish hard. Total removal of nodular tumor and subtotal removal of the cyst wall were performed. He has been doing well for these 3 years following craniotomy and has no deficit without CT evidence of recurrent tumor. Histologically the tumor cells displayed marked pleomorohism. However either necrosis or mitosis were not seen. Frequently these cells had vacuolated or foamy cytoplasm. There were many of the giant cells and multinucleated cells. In some area, these tumor cells were surrounded by a fine network of reticulin fibers. Electron microscopically the tumor cells were occasionally filled with glial filament and lipid granules were seen. Immunoperoxidase technique revealed GFAP in the cytoplasm of the tumor cells. This case was considered to be pleomorphic xanthoastrocytoma first proposed by Kepes.     

Pleomorphic xanthoastrocytoma with anaplastic features presenting without GFAP immunoreactivity: Implications for differential diagnosis

Pleomorphic xanthoastrocytoma (PXA) is an uncommon, usually low‐grade, astrocytic tumor. Characteristic histological features include tumor cell pleomorphism and lipidization of tumor cells. Albeit prognosis in PXA is generally good, cases with histological signs of anaplasia have been observed. In these cases, the differential diagnosis needs to exclude other malignancies, for example, glioblastoma or malignant fibrous histiocytoma. Immunocytochemical detection of GFAP may support exclusion of non‐glial neoplasms resembling PXA. However, GFAP expression in PXA may be faint or focal, although complete lack of GFAP has not been described. A 43‐year‐old woman was operated on for a left occipital parasagital tumor attached to the dura. Histopathology showed a pleomorphic tumor with moderate mitotic activity and necrosis, lack of GFAP immunoreactivity and ultrastructural detection of premelanosome‐like structures. These features led to the tentative diagnosis of amelanotic melanoma, and the patient was irradiated. Three years later she had local tumor recurrence and underwent another operation. The recurrent tumor showed similar plain histology as the first specimen. In contrast, anti‐GFAP immunoreactivity was now detectable in pleomorphic tumor cells. Anti‐GFAP staining of the first biopsy was repeated using monoclonal and polyclonal antibodies in combination with prolonged tissue pretreatment. Focal GFAP staining of tumor cells was now achieved. We conclude that non‐standard GFAP staining protocols may enhance sensitivity and thus lead to detection of a low level of GFAP expression in tumor specimens, in which PXA is considered in the differential diagnosis. This may avoid misleading diagnostic considerations that impact on postoperative patient management.     

Metastatic pleomorphic xanthoastrocytoma in the scalp

We present a 27-year-old Chinese male with a rare pleomorphic xanthoastrocytoma (PXA) that underwent transformation with metastasis to the scalp. To our knowledge this is the first report of a PXA undergoing malignant transformation and metastasizing to the scalp and provides further evidence that PXA may not be as benign as previously believed.     

Diffuse leptomeningeal spread of pleomorphic xanthoastrocytoma

Diffuse meningeal spread and dural infiltration by pleomorphic xanthoastrocytoma occurring after initial diagnosis of a left frontotemporal lesion is reported. The unusual pattern of spread and aggressive course for a pleomorphic xanthoastrocytoma are discussed.     

Molecular genetic alterations in pleomorphic xanthoastrocytoma

Pleomorphic xanthoastrocytoma (PXA) is a low-grade glioma that may recur as a malignant diffuse astrocytoma such as glioblastoma (GBM). While the molecular genetic basis of diffuse astrocytomas has been studied extensively, PXAs have not been analyzed in detail. We, therefore analyzed DNA from archival primary and recurrent PXAs from eight patients (three grade II PXAs without recurrence, one grade II PXA with recurrence as grade II PXA, two grade II PXAs with progression to GBM, and two grade III anaplastic PXAs with recurrence as grade III anaplastic PXA or GBM) for genetic changes associated with diffuse astrocytomas. Single-strand conformation polymorphism analysis of p53 exons 5–8 revealed migration shifts in two cases, one primary PXA without recurrence and one recurrent grade II PXA in which the primary tumor did not show a shift. DNA sequencing showed two missense mutations in codons 220 (exon 6) and 292 (exon 8), respectively, mutations which have not been previously noted in astrocytomas. Differential polymerase chain reaction analysis demonstrated epidermal growth factor receptor gene amplification in only one tumor, a GBM without allelic loss of chromosome 10 that was the second GBM recurrence of an initial grade II PXA. Loss of heterozygosity studies on tumors from five patients, using three microsatellite polymorphisms on chromosome 10q and three on chromosome 19q, did not disclose allelic loss in any recurrent tumor. These findings suggest that the genetic events that underlie PXA formation and progression may differ significantly from those involved in diffuse astrocytoma tumorigenesis. Received: 18 July 1995 / Revised, accepted: 15 September 1995     

多形性黄色瘤型星型细胞瘤的诊断与治疗

目的探讨多形性黄色瘤型星形细胞瘤病人的临床特征及治疗。方法回顾8例多形性黄色瘤型星形细胞瘤病人的临床资料。病人平均年龄23．7岁，肿瘤均位于大脑半球。以癫痫起病，确诊主要依靠病理学检查。结果肉眼全切1例，显微手术全切4例，大部分切除3例；术后行放疗3例，放、化疗2例。随访10个月～5年，6例病情稳定，癫痫及头痛得到控制；2例复发，其中1例死亡。结论多形性黄色瘤型星形细胞瘤相对良性，癫痫发作是最常见的症状。治疗上应尽量手术全切，对术后有残余、复发或间变者可给予化、放疗。