An Updated Comparison Between World Health Organization Grade II Gemistocytic and Diffuse Astrocytoma Survival and Treatment Patterns.

BACKGROUND: In 2016, the World Health Organization revised its guidelines to retain only gemistocytic astrocytoma (GemA) as a distinct variant of diffuse astrocytoma (DA). In the past, grade II GemAs were linked with a worse prognosis than DA. However, it is unclear how consistently the tumor subtype has been diagnosed over time. We used more recent data to compare outcomes between grade II GemA and DA. METHODS: Patients with grade II DA and GemA were extracted from the Surveillance, Epidemiology, and End Results database between 1973 and 2016. Kaplan-Meier curves estimated survival differences across different eras, with a focus on patients diagnosed between 2000 and 2016, and propensity score matching was used to balance baseline characteristics between DA and GemA cohorts. RESULTS: Of 2467 patients with grade II astrocytoma diagnosed between 2000 and 2016, 132 (5.35%) had GemA, and 2335 (94.65%) had DA. At baseline, marked demographic and treatment differences were noted between tumor subtypes, including age at diagnosis and female sex. GemA patients did not have worse survival compared with DA patients at baseline (P = 0.349) or after propensity score matching (P = 0.497). Multivariate Cox models found that surgical extent of resection was associated with a survival benefit for DA patients, and both DA and GemA patients >65 years old had dramatically inferior survival. CONCLUSIONS: Our data suggest that the impact of GemA versus DA histopathology depends more on the decade of queried data rather than patient-specific demographics. Using more recent longitudinal data, we found that grade II GemA and DA tumors did not have significant differences in survival. These data may prove useful for clinicians counseling patients with grade II GemA.

Imaging and Radiologic-Pathologic Correlation in Granular Cell Astrocytomas: Report of 2 Cases.

BACKGROUND: Granular cell astrocytoma is a rare and aggressive subtype of astrocytoma that is histopathologically well defined in the literature. It is formed by polygonal cells with granular cytoplasm mixed with neoplastic astrocytes and usually a perivascular infiltrate of lymphocytes. Despite its unusual histologic appearance, relevant radiologic features have not yet been described. CASE DESCRIPTION: We report 2 middle-aged patients with neurologic symptoms secondary to a newly diagnosed brain tumor. The absence of central tumor necrosis as well as the presence of an atypical pattern of enhancement and areas of intense diffusion restriction on magnetic resonance imaging in both cases led to the diagnosis of primary central nervous system lymphoma. Histopathologic findings in both tumors showed an aggressive astrocytoma with a prominent granular cell population and perivascular lymphocytic cuffing in tissue, corresponding to a granular cell astrocytoma. Despite the favorable prognostic factors, including World Health Organization grades II and III astrocytomas and IDH mutations, the outcome was poor. CONCLUSIONS: Granular cell astrocytomas can show unusual aggressive radiologic features that do not correspond to their histopathologic grade of malignancy. The presence of perivascular lymphocytic infiltrate may alter the typical radiologic appearance of common astrocytomas.

[Gemistocytic astrocytomas]. / Gemistotsitarnye astrotsitomy.

Gemistocytic astrocytomas (GA) are a variant of diffuse astrocytomas GII (WHO, 2016). Like all diffuse astrocytomas, GA recur with time, which is often accompanied by malignant degeneretion into the anaplastic astrocytoma GIII or to the secondary glioblastoma GIV. However, the progression-free survival and overall survival in patients with GA is less than in patients with diffuse astrocytomas. Given that this group of patients, according to the WHO classification (2016), is classified as GII, patients with GA usually do not receive comprehensive treatment. We have conducted a thorough analysis of research on this problem for the period from 1956 to 2017. Differences in the histological pattern, immunohistochemical and molecular-genetic profiles, survival of patients with GA and diffuse astrocytomas GII are shown there. A clinical case of a patient with transformation of a diffuse astrocytoma in GA (GIII) and then into a secondary glioblastoma is presented.

Prognostic relevance of gemistocytic grade II astrocytoma: gemistocytic component and MR imaging features compared to non-gemistocytic grade II astrocytoma.

OBJECTIVES: To determine if gemistocytic grade II astrocytoma (GemA) and its MR imaging characteristics are associated with a shorter time-to-progression (TTP) compared with non-gemistocytic grade II astrocytoma (non-GemA). MATERIALS AND METHODS: We enrolled 78 patients who were followed up more than 5 years (29 pathologically proven GemA and 49 non-GemA) during a 10-year period. Contrast-enhanced T1-weighted, diffusion-weighted imaging (DWI), dynamic susceptibility contrast (DSC), and MR spectroscopy (MRS) and clinical data were retrospectively reviewed. Clinical and MR imaging features were analyzed as possible prognostic factors of high-grade transformation, and multivariate analysis of TTP was performed using Cox proportional modeling. RESULTS: GemA showed more frequent high-grade features than non-GemA, including diffusion restriction (P < .001), increased choline/creatine (P = .02), and increased choline/NAA ratio (P = .015). Patients with GemA had a significantly shorter median TTP (53.1 vs 68 months; P < .001). A gemistocytic histopathology (hazard ratio = 3.42; P = .015) and low ADC (hazard ratio = 3.61; P = .001) were independently associated with a shorter TTP. CONCLUSIONS: GemA can present with MR imaging findings mimicking high-grade glioma at initial diagnosis and transforms to high-grade disease earlier than non-GemA. Low ADC on DWI might be useful in stratifying the risk of progression in patients with grade II astrocytoma. KEY POINTS: • Gemistocytic grade II astrocytoma (GemA) showed more frequent high-grade features than non-GemA. • Patients with GemA had a significantly shorter median TTP than non-GemA. • Gemistocytic histopathology and low ADC were independently associated with shorter TTP.

Magnetic resonance imaging features of gemistocytic astrocytoma.

INTRODUCTION: Gemistocytic astrocytoma is the second most common subtype of World Health Organization grade 2 astrocytoma, but has a worse prognosis than other grade 2 lesions. We aim to describe the MR imaging features of histopathologically proven gemistocytic tumours. METHODS: Ethics approval was obtained from both institutions. Patient consent was not required for this retrospective study. We reviewed MR imaging findings of 16 consecutive cases of histopathologically proven gemistocytic astrocytoma and anaplastic astrocytoma with gemistocytic features. RESULTS: Average patient age was 48 years, with a 3:1 male to female ratio. Based on our series, the typical appearance of a gemistocytic astrocytoma is a large, heterogeneous mass most commonly supratentorial and lobar. Regions of cyst formation, partial signal suppression on FLAIR images and contrast enhancement are all common features. Additionally, contrary to previous literature that describes gemistocytic astrocytoma as a purely supratentorial lesion, we present two cases of gemistocytic astrocytoma involving the brainstem. CONCLUSIONS: The possibility of gemistocytic astrocytoma should be considered in patients presenting with large heterogeneous tumours that have regions of cyst formation, partial FLAIR suppression and contrast enhancement. This may be especially useful in reconciling a lesion with high-grade MR imaging features with low-grade histopathology. An infratentorial location does not preclude the diagnosis of gemistocytic astrocytoma.

Unusual synchronous presentation of maxillary sinus fibrosarcoma and gemistocytic astrocytoma with a complication called leukocytoclastic vasculitis: a case report.

Fibrosarcoma of the paranasal sinuses is extremely rare pathology and there is limited report in the literature. We report synchronous presentation of maxillary sinus fibrosarcoma and gemistocytic astrocytoma which is, to our knowledge, unique in the literature. Both tumors metastases to other organ rarely and the metastatic spread of gemistocytic astrocytoma to fibrosarcoma or vice versa have also not been reported in the literature yet. This report discusses the clinical course of the disease, outcome of the treatment approach and survival as well as an unusual occurrence of leukocytoclastic vasculitis during the course of radiotherapy in such unusual presentation.