Cerebral gliosarcoma: Analysis of 16 patients and review of literature

Abstract

Background: Gliosarcoma (GS), a subtype of glioblastoma (GBM), is a rare primary neoplasm of the central nervous system. Certain features like temporal lobe affinity, tendency for extraneural metastasis and poorer outcome compared to GBM indicate that GS may indeed be a separate clinicopathologic entity. This led us to revisit this entity in our settings.

Materials and methods: Between 2009 and 2014, 16 cases of histologically proven GSs (14 primary, two secondary) were treated. Patient data were retrieved retrospectively. Statistical analysis was performed with? Statistical Package for Social Sciences, version 17.0. (Chicago, Illinois, USA). Survival was analyzed by Kaplan-Meier method.

Results: GS predominantly affected males in their fifth decade of life. Raised intracranial pressure was the most common mode of clinical presentation. Temporal lobe was the most commonly affected part of the brain and majority of primary and all of secondary GBM were located peripherally. In 7 (43.8%) patients, tumor was radiologically well-demarcated and enhanced strongly and homogenously on contrast as compared to 9 (56.2%) patients where the tumor was ill-defined and showed heterogenous patchy or ring enhancement. Extent of excision was total in seven patients (43.8%), near total in 4 (25%) and subtotal in five patients (31.2%). Median survival was 6 months. Patients with well-demarcated, enhancing mass on imaging intraoperatively had firm tumors with a good plane of cleavage and had a better survival (8 months) compared to those in whom the tumor radiologically and intraoperatively mimicked GBM (2 months).

Conclusion: GS is associated with poor survival (median survival 6 months). Radiological and intraoperative findings help categorize these tumors into GBM like GS and meningioma like GS. While the former histologically mimics GBM and has very poor survival (2 months), GS with meningioma like feature tends to have better survival (8 months).

Keywords: Chemotherapy; glioblastoma; gliosarcoma; immunohistochemistry; pathology; surgery; survival.

Figure 1

Hyperdensity suggestive of bleed in left subcortical temporal lobe (a). The lesion appeared hyperintense on T1 and hypointense on T2 further demonstrating bleed inside the lesion (b and c). After resolution of hematoma, a peripherally enhancing mass lesion can be seen on axial computed tomography (1-year after initial bleed) (d). Postoperative computed tomography scan showed complete excision of tumor (e)

Figure 2

Hyperdense right temporal cortical mass with extensive perilesional edema was seen on CT(a). The mass was heterogenously hypointense on T1 and hyperintense on T2 with heterogenous but strong postcontrast enhancement (b,c,d,e). Dural tail sign was seen in the axial section (d). Postoperative scan showed complete excision (f)

Figure 3

A T1 isointense to hypointense and T2 isointense to hyperintense large right frontoparietal heterogenous mass lesion showing peripheral ring-like enhancement with edema and mass effect (a-c). Postoperative scan shows subtotal excision with residual tumor abutting posterior limb of internal capsule (d)

Figure 4

Left frontoparietal glioblastoma which was heterogeneously hyperintense on T2 and showed intense enhancement (a and b). Contrast computed tomography head done 2 years after surgery and radiotherapy shows an ill-defined mass at the site of the original tumor and patchy enhancement (c). Postoperative image shows evidence of ear total excision (d)

Figure 5

Dural-based T2 hyperintense (a) and sharply delineated homogenously enhancing right frontal secondary gliosarcoma displaying dural tail sign (b and c). Craniotomy defect of earlier surgery for glioblastoma can be seen in all the images

Figure 6

(a) Tumor disposed in sheets showing pleomorphic cells displaying anisomorphic nuclei, frequent mitosis (H and E, ×100). Areas of spindle tumor cells displaying anisonucleosis are also noted (b) (H and E, ×200). Foci of reticulin-rich tumor cells (c: Reticulin, ×40) suggest sarcomatous component. Glial fibrillary acidic protein (GFAP) positive tumor cells seen in glial component and interspersed glial GFAP negative tumor cells suggest sarcomatous component (d and e: GFAP, ×200)

Figure 7

The survival curve. The median overall survival was 6 months