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

Clinical features and surgical outcomes of high grade pleomorphic xanthoastrocytomas: a single-center experience with a systematic review

Purpose

High grade pleomorphic xanthoastrocytomas (HGPXAs) are very rare and their management and prognostic outcomes remain unclear. To better understand the disease, we aimed to evaluate the risk factors for progression-free survival (PFS) and overall survival (OS), and propose a treatment protocol based on cases from our institute and cases from the literature.

Methods

The authors reviewed the clinical data of 26 patients with HGPXAs who underwent surgical treatment in Department of Neurosurgery of Beijing Tiantan Hospital between August 2014 and September 2021. We also searched the PubMed database using the keywords "anaplastic" combined with "pleomorphic xanthoastrocytoma(s)" between January 1997 and October 2022. Risk factors for PFS and OS were evaluated in the pooled cases.

Results

The authors' cohort included 11 males and 15 females with a mean age of 36.7 ± 20.3 years (range: 5.5-71 years). Gross-total resection (GTR) and non-GTR were achieved in 17 (65.4%) and 9 (34.6%) patients, respectively. Radiotherapy and chemotherapy were administered to 22 and 20 patients, respectively. After a mean follow-up of 20.5 ± 21.2 months (range: 0.5-78.1 months), 7 patients suffered tumor recurrence and 6 patients died with a mean OS time of 19.4 ± 10.8 months (range: 8-36 months). In the literature between January 1997 and October 2022, 56 cases of HGPXAs were identified in 29 males and 27 females with a mean age of 29.6 ± 19.6 years (range; 4-74 years). Among them, 24 (44.4%) patients achieved GTR. Radiotherapy and chemotherapy was administered to 31 (62%) patients and 23 (46%) patients, respectively. After a median follow-up of 31.4 ± 35.3 months (range: 0.75-144 months), the mortality and recurrence rates were 32.5% (13/40) and 70% (28/40), respectively. Multivariate Cox regression model demonstrated that non-GTR (HR 0.380, 95% CI 0.174-0.831, p=0.015), age≥30 (HR 2.620, 95% CI 1.183-5.804, p=0.018), no RT (HR 0.334,95% CI 0.150-0.744, p=0.007) and no CT (HR 0.422, 95% CI 0.184-0.967, p=0.042) were negative prognostic factors for PFS. Non-GTR (HR 0.126, 95% CI 0.037-0.422, p=0.001), secondary HGPXAs (HR 7.567, 95% CI 2.221-25.781, p=0.001), age≥30 (HR 3.568, 95% CI 1.190-10.694, p=0.023) and no RT (HR 0.223,95% CI 0.073-0.681, p=0.008) were risk factors for OS.

Conclusion

High grade pleomorphic xanthoastrocytomas are very rare brain tumors. Children and younger adults have better clinical outcome than elderly patients. Secondary HGPXAs had worse OS than primary HGPXAs. Complete surgical excision plus RT and CT is recommended for this entity. The frequency of BRAF mutations in HGPXAs is 47.5% (19/40) in this study, however, we do not find the connections between BRAF mutations and clinical outcomes. Future studies with larger cohorts are necessary to verify our findings.

Malignant transformation of pleomorphic xanthoastrocytoma in pregnant patient: Clinical case and ethical dilemma

Background:

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor, accounting for <1% of astrocytic tumors. Due to its rarity, etiology, natural history, and biologic behavior is not completely explained. We present a case of malignant transformation of a PXA to glioblastoma in pregnant patient 6 month after tumor biopsy.

Case Description:

A 28-year-old female patient was presented with a newly onset of headache, nausea, and right-sided hemiparesis at 21^st week of pregnancy. Magnetic resonance imaging (MRI) revealed cystic mass in the left frontal region. Patient underwent biopsy to confirm pathohistological analysis; the tumor tissue corresponded to an anaplastic PXA. Two weeks after initial biopsy, open surgery along with gross total tumor removal was performed confirming pathohistological analysis. Six months later, after childbirth, and control MRI revealed a recurrent tumor mass: the patient underwent surgical resection and the tumor tissue corresponded to a glioblastoma. The patients were further treated with radiation and chemotherapy according to oncologist.

Conclusion:

Distinguishing between PXA patients who have a good prognosis and those at risk for early progression is very important for the PXA clinical management. Despite cellular pleomorphism, mitotic index and the extent of resection are shown to be the main predictors for recurrence-free survival and overall survival rates. The standard therapy management is not yet established. Our patient treatment was associated with a significant ethical dilemma. Respecting patient’s wishes to deliver a baby, nor radio or chemo treatments were done. Further studies are necessary to provide factors responsible for malignant transformation of PXA. In addition, in ethically sensitive situation, such as tumor in pregnant patient, good communication, respecting patient’s wishes, and a multidisciplinary teamwork is the key for better outcome.

Differences in treatment patterns and overall survival between grade II and anaplastic pleomorphic xanthoastrocytomas

INTRODUCTION

Pleomorphic xanthoastrocytomas (PXAs) are classified as a grade II neoplasm, typically occur in children, and have favorable prognoses. However, their anaplastic counterparts remain poorly understood and vaguely characterized. In the present study, a large cohort of grade II PXA patients were compared with primary anaplastic PXA (APXA) patients to characterize patterns in treatment and survival.

METHODS

Data were collected from the National Cancer Institute's SEER database. Univariate and multivariate Cox regressions were used to evaluate the prognostic impact of demographic, tumor, and treatment-related covariates. Propensity score matching was used to balance baseline characteristics. Kaplan-Meier curves were used to estimate survival.

RESULTS

A total of 346 grade II PXA and 62 APXA patients were identified in the SEER database between 2000 and 2016. Kaplan-Meier analysis revealed substantially inferior survival for APXA patients compared to grade II PXA patients (median survival: 51 months vs. not reached) (p < 0.0001). After controlling across available covariates, increased age at diagnosis was identified as a negative predictor of survival for both grade II and APXA patients. In multivariate and propensity-matched analyses, extent of resection was not associated with improved outcomes in either cohort.

CONCLUSIONS

Using a large national database, we identified the largest published cohort of APXA patients to date and compared them with their grade II counterparts to identify patterns in treatment and survival. Upon multivariate analysis, we found increased age at diagnosis was inversely associated with survival in both grade II and APXA patients. Receipt of chemoradiotherapy or complete surgical resection was not associated with improved outcomes in the APXA cohort.

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.

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.

Clinicopathological and imaging features of lipoastrocytoma: Case report

Lipidized tumors of the central nervous system are very uncommon, with only a few cases described. We report a case of a 25-year-old woman with a tumor involving the left premotor area. She underwent gross total excision. Histologically, the tumor was composed of glial fibrillary acidic protein-positive glial cells with areas of lipidization. A diagnosis of lipoastrocytoma was rendered. At three-year follow-up she was doing well, supporting the presumed favorable prognosis of these uncommon tumors. Absence of xanthochromic appearance, mitotic activity, necrosis and poor reticulin activity are the differentiating features from the pleomorphic xanthoastrocytoma. We highlighted that these tumors involve the adult and pediatric population and distribute in both supratentorial and infratentorial compartments as well as in the spinal cord.

Primary anaplastic pleomorphic xanthoastrocytoma in adults. Case report and review of literature

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A case report and literature review of anaplastic pleomorphic xanthoastrocytoma in adults.

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The tumor shows an aggressive clinical course compared with its benign variant.

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APXA shows histological characteristics comparable with grade III astrocytomas.

Background

Pleomorphic xanthoastrocytoma (PXA) classified as a low Grade (WHO II) astrocytic neoplasm. It is known for its relatively favorable prognosis. It most commonly occurs in young adults. Malignant progression in PXA has been frequently reported since its first description in 1979; however, the presentation of a primary anaplastic PXA tumor with an aggressive clinical course in adults is rare especially in the later age group.

Case description

We present a case of primary anaplastic PXA in a 53 year old male that manifested with an early recurrence pattern at 9 weeks. Treatment performed was surgical excision and external beam radiotherapy. The aforementioned tumor followed an aggressive clinical course. Tumor cells exhibited the characteristic expression of GFAP (Glial fibrillary acidic protein), higher proliferative index (8–10%) on Ki-67 staining along with the presence of increased mitoses ( >5/10hpf). A review of previously reported primary anaplastic pleomorphic xanthoastrocytoma cases in adults with histological features was also done.

Conclusion

Our review of all reported cases of APXA in adults concludes that the clinical behavior of this tumor varies considerably from its benign variant. Early disease recurrence in anaplastic pleomorphic xanthoastrocytomas is associated with fatal outcomes. As per our review of literature it is seen that anaplastic variant of PXA shows histological characteristics as well as clinical course comparable with Grade III astrocytomas.

We recommend further evaluation of PXA with anaplastic features regarding their genetic characteristics to understand the origin as well as behavior of this tumor.

Glioblastoma multiforme versus pleomorphic xanthoastrocytoma with anaplastic features in the pathological diagnosis: a case report

Background

Pleomorphic xanthoastrocytoma (PXA) with anaplastic features should be strictly distinguished from glioblastoma multiforme (GBM).

Case presentation

A case of PXA that was initially diagnosed as GBM is presented. A 42-year-old man visited our clinic because of right hemiparesis and total aphasia. Head magnetic resonance imaging demonstrated enhanced multiple cystic lesions in the left temporal lobe suggesting an intra-parenchymal brain tumor. The lesion was partially removed and GBM with a Ki-67 index of 20 % was diagnosed by pathological examination of the resected specimen. Despite receiving radiation and chemotherapy, the patient died 6 months after the first admission. At autopsy, the boundary between the tumor and normal brain tissue was clear. Large parts of the tumor demonstrated typical features of PXA, including pleomorphism, clear xanthomatous cells with foamy cytoplasm, positive silver staining, and a Ki-67 index of less than 1 %.

Discussion and conclusions

GBM should be diagnosed only when the majority of the tumor cells are undifferentiated. Although the operative specimen appeared typical GBM histologically, the diagnosis of GBM was subsequently excluded by the autopsy finding that much of the tumor had the characteristic features of a benign PXA. Therefore, the final diagnosis in this case was PXA with anaplastic features. PXA with anaplastic features should be carefully distinguished from GBM to facilitate appropriate decisions concerning treatment.

Low-grade gliomas in children: single institutional experience in 198 cases

INTRODUCTION

In pediatric population (0-18 years), low-grade gliomas (PLGG) are the most frequent brain tumors and majority are amenable for surgical removal.

PATIENTS AND METHODS

A retrospective review of 198 children diagnosed with PLGG between 1980 and 2010 at HSJD was carried out. Several variables were studied to find prognostic factors related to the outcomes (progression-free survival (PFS) and overall survival (OS)).

RESULTS

Median age at onset was 88.8 months (3.1 to 214.5 months, SD 53). Surgery was performed in 175 patients (88.4%), achieving gross total resection (GTR) in 77 (44%), subtotal resection (STR) in 87 (49.7%), and 11 (6.3%) biopsies. Pathological review classified 84 tumors as WHO grade I (48%) and 89 as grade II (50.8%). Adjuvant therapy (AT) was given to 75 patients (37.9%), radiotherapy in 24 (12.1%), chemotherapy in 33 (16.7%), and combined in 18 (9.1%). Sixteen patients (8.1%) died, 89 (43.4%) are alive with no evidence of disease, and 93 (47%) alive with disease, median follow-up 65.2 months. Outcome is significantly correlated with age (p = 0001, worse OS for patients younger than 12 months) and extent of tumor resection (p < 0001). OS for GTR/STR/biopsy was >200, 154.3, and 101.9 months, respectively. Patients treated with AT presented worse OS/PFS (p < 0.001) than those not treated. Histology was non significantly related to outcomes.

CONCLUSION

In our series of PLGG, the best prognostic markers are tumor location (cerebellar) and the extent of tumor resection (GTR). Infants and patients who require adjuvant therapy because of tumor progression or recurrence have worse outcome.

Aggressive behavior and anaplasia in pleomorphic xanthoastrocytoma: a plea for a revision of the current WHO classification

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic neoplasm that commonly affects children and young adults, and presents with seizures. PXA is typically supratentorial with a predilection to the temporal lobe, and often involves the cortex and the meninges. PXAs have a favorable prognosis with a 10-year survival probability of >70%, and are WHO grade II neoplasms. Recent observations and studies demonstrate that PXAs are clinically, histologically and genetically distinct. Some PXAs recur and exhibit aggressive clinical behavior. In such cases, certain histological and clinical factors could account for the aggressive behavior. However, the histological features that predict adverse outcome are poorly defined. In the current WHO classification of CNS tumors, there is no option for a high-grade PXA, even if the tumor had numerous recurrences and poor outcome. In this review, we focus on aggressive clinical behavior and anaplasia in PXA, and discuss how our current experience suggests modifications in the current WHO classification. We also review recent discoveries on the molecular characteristics of PXA that could help us better understand their biological behavior.

Lipoastrocytoma: A rare case report and review of literature

Lipoastrocytoma is an extremely rare tumor, with only a few cases described. We report a case of a low-grade astrocytoma occupying the right cortical lobe in the parafalcine location. The patient was admitted with headache, vomiting and altered sensorium for duration of 1 year. MRI revealed a large heterogeneous enhancing mass in the right fronto-parieto-temporal lobe with intratumoral fat along with cystic changes and calcification (correlated with CT) showing mass effect in the third ventricle. A gross total excision of the tumor was performed. Histologically, the tumor showed glial cells that contained lipid droplets coalescing into a single large droplet, similar in appeareance to adipocytes. Immunohistocemically, tumor cells strongly expressed GFAP and S-100 protein. Ki-67 labelling index was low. The patient remained in good neurological condition at 3 months follow-up. This case represents a rare variant of low-grade astrocytoma that is designated as lipoastrocytoma.

Invasion patterns in brain metastases of solid cancers

BACKGROUND

Brain metastases are generally considered to be well demarcated from the surrounding brain parenchyma, although infiltrative growth patterns have been observed. We systemically investigated infiltration patterns and expression of adhesion molecules in a large and well-defined series of autopsy cases of brain metastases.

METHODS

Ninety-seven autopsy specimens from 57 brain metastasis patients (primary tumor: 27 lung cancer, 6 breast cancer, 8 melanoma, 2 colorectal cancer, 1 kidney cancer, and 13 other) were evaluated for patterns of invasion into surrounding brain parenchyma. Expression of integrins αv; cytoplasmic β3, αvβ3, αvβ5, αvβ6, and αvβ8; and of E and N cadherin were evaluated using immunohistochemistry.

RESULTS

Three main invasion patterns were seen: well-demarcated growth (29/57, 51%), vascular co-option (10/57, 18%), and diffuse infiltration (18/57, 32%). There was no statistically significant association of invasion pattern with primary tumor type, although vascular co-option was most common in melanoma brain metastases (4/10). Invasion patterns of different brain metastases of the same patient were highly concordant (P < .001, chi-square test). Distance of infiltration from the main tumor mass ranged from 12.5 µm to 450 µm (median 56.2 µm) and was not significantly different between the vascular co-option and the diffuse infiltration groups. Levels of αvβ6 were significantly higher in the well-demarcated group than in the vascular co-option and the diffuse infiltration groups (P = .033, Kruskal-Wallis test). Expression of αvβ5 in tumor cells was higher in brain metastasis lesions previously treated with stereotactic radiosurgery (P = .034, chi-square test).

CONCLUSIONS

Distinct invasion patterns of brain metastases into the brain parenchyma are not specific for primary tumor types, seem to be influenced by expression of αv integrin complexes, and may help to guide clinical decision-making.

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.

Pleomorphic granular cell astrocytoma in the pineal gland: case report

Pleomorphic granular cell astrocytoma in the pineal region is exceedingly rare, and its clinicopathological features are distinctive. A 67-year-old woman was admitted with a staggering gait. Magnetic resonance imaging revealed a mass lesion at the pineal gland accompanied by obstructive hydrocephalus. Following surgery, pathological examinations demonstrated a pleomorphic granular cell astrocytoma. The patient has been free from recurrence for 24 months after surgery without adjuvant therapy. The specimen exhibited nuclear and cytoplasmic pleomorphism. The nuclei varied in size, shape and coarseness. Variability was also observed in the eosinophilic granular bodies, Rosenthal fibers and spindle-shaped tumor cells. GFAP, S-100 and vimentin were immunohistochemically positive. Reticulin network was absent between the tumor cells, and granular cells with ballooned cytoplasm showing positive staining for PAS. Pleomorphic granular cell astrocytoma is believed to be a form of astrocytoma originating from the pineal gland. Its clinicopathological features resemble those of pleomorphic xanthoastrocytoma. However, it can be differentiated from the latter by the absence of reticulin fibers, absence of basement membrane between adjacent cells, and presence of large numbers of mitochondria.

Lipoastrocytoma: Case report and review of the literature

Lipoastrocytoma is an extremely rare tumor, with only six cases described. We report the case of an astrocytoma involving the upper part of the cerebellar-pontine angle and the right portion of the clivus starting from the brainstem with a diffuse lipomatous component in a 39 year-old man. The patient was admitted with headache of 1 year's duration and diplopia over the previous 3 months. MRI revealed a ponto-cerebellar lesion that showed irregular enhancement after contrast administration. Subtotal excision of the tumor was accomplished. Adjuvant chemotherapy and radiation therapy were not administered. Histologically the tumor showed the classical histology of low-grade astrocytoma and a portion of the lesion was composed of lipid-laden cells. Immunohistochemistry for glial fibrillary acid and S-100 proteins clearly demonstrated the glial nature of these cells. Ki-67/Mib-1 labeling index was low (2%). The patient remains in good neurological conditions after 10 months. Our case has a benign postoperative behavior, also after subtotal excision, with restrictions due to the short follow-up. It is important to record each new case of this rare tumor to produce a better characterization of this lesion.

Malignant progression in pleomorphic xanthoastrocytoma: Personal experience and review of the literature

Pleomorphic xanthoastrocytoma (PXA) is a rare primary low-grade astrocytic tumor, recently classified as a neuroglial tumor. It generally occurs in children and young adults and shows benign behaviour (WHO II), although an anaplastic variant and malignant potential have been described. Pleomorphic xanthoastrocytomas with malignant transformation have been reported in three out of eight patients operated on for this type of tumor in our department in the last 15 years. The three patients were two adult women and a child, the primary tumors were located in the cortex of the right temporal lobe, and treatment consisted of complete surgical resection. Histological examination revealed simple PXA in two patients and a PXA with anaplastic foci in the other. Mean recurrence time was 5.7 years, with the original xanthoastrocytoma evolving to glioblastoma in two cases and anaplastic astrocytoma in the third. All three patients underwent a second operation, followed by adjuvant therapies. Two died from tumor progression and one from brain edema after intracerebral haemorrhage. A review of the available PXA literature dating back to 1979 revealed 16 cases of primary anaplastic astrocytoma and 21 cases of PXA with malignant transformation. Our experience adds three more cases of malignant transformations, outlining once again the potential malignancy of pleomorphic xanthoastrocytomas and the fact that prognosis in these cases is the same as for primary anaplastic astrocytoma and glioblastoma. Analysis of glioneuronal markers, Ki67 and p53 in all pleomorphic xanthoastrocytomas did not prove to be a discriminating factor to identify a subgroup of xanthoastrocytomas prone to malignancy. Accordingly, these tumors demand close long-term clinical and radiological follow-up.

Spindle cell oncocytoma of the adenohypophysis: report of a case with a 16-year follow-up

Spindle cell oncocytoma (SCO) is a recently described, rare neoplasm of the anterior pituitary. Clinically and radiologically simulating a non-functioning macroadenoma, its eponymous fusiform cells display a non-epithelial phenotype with conspicuous cytoplasmic accumulation of mitochondria. We report a case of SCO retrospectively identified in a biopsy specimen 16 years after transsphenoidal operation of a 48-year-old woman. Presenting symptoms were adynamia and transient decrease of visual acuity. Neuroimaging showed an isointense, enhancing, sellar-centered mass 1.8 cm in diameter without evidence of invasive growth. No postoperative adjuvant therapy was administered. The patient was left with panhypopituitarism, yet no recurrence was seen during follow-up. Initially diagnosed as a null cell adenoma of oncocytic type, repeat immunohistochemistry showed the characteristic coexpression of S100 protein, vimentin, and epithelial membrane antigen. Oncocytic granula stained intensely with antimitochondrial antibody 113-1, and were negative with the lysosomal marker CD68. Anterior pituitary hormones tested negative, and there was no evidence of neuroendocrine differentiation using antibodies to synaptophysin and chromogranin. Few cells stained for glial fibrillary acidic protein (GFAP). SCO has been proposed to represent a neoplasm of folliculo-stellate cells (FSCs). While the dynamic properties of the latter are incompletely characterized, and indeed no specific marker allows for their identification, overlapping features of SCO with look alikes, in particular pituicytoma, point to FSCs being a potential adult stem cell. The favorable outcome of the present case further argues for SCO to be considered a low-grade neoplasm. Moderate tumor size, lack of invasiveness, and low proliferation rate are likely predictors of benign behavior.