Gliosarcoma (GS) was firstly described by Stroebe in 1895 as a double face neoplasm, composed, respectively, by glial and mesenchymal elements [
A 33-year-old pregnant woman (G2P1A1) on the 15th week of gestation was admitted to our Emergency Department with a 3-week history of headache and unsteadiness followed by rapid worsening within 5 days characterized by projectile vomiting, confusion, and psychomotor agitation. A brain magnetic resonance imaging (MRI) scan showed tetraventricular hydrocephalus secondary to obstruction of the cerebrospinal fluid through the foramina of Luschka and Magendie caused by a homogenously enhancing cortical-subcortical lesion localized on the right cerebellar hemisphere, responsible for perilesional edema and characterized by evidence of dural infiltration. The latter, initially mistaken for dural tail, oriented toward the suspicion of posterior fossa meningioma (see Figure
Preoperative T1 postgadolinium injection MRI (a) sagittal, (b) coronal and (c) axial, showing a meningioma-like lesion, localized at the base of the posterior cranial fossa and reaching the cortex of the right cerebellar hemisphere. Note the dural tail (black arrow) and the dilatation of the ventricular system (white arrow).
Given the critical clinical and radiological scenario, surgical excision was expedited. The patient successfully underwent a suboccipital craniectomy in a sitting position, with the insertion of external ventricular drain (EVD) through the right Keen’s point and gross-total removal of the lesion, which resembled an aggressive glioma rather than a meningioma. The general anesthesia was carefully tuned to avoid any impact on the fetus’ wellbeing; the postoperative course was uneventful, the EVD was removed within 1 week, and the patient experienced a full recovery with unremarkable neurological status at the time of discharge from the hospital. The histology and the immunohistochemistry analysis surprisingly gave a final diagnosis of GS (see Figure
Sections of the tumor showing distinct gliomatous and sarcomatous areas. (a) Cerebellar normal tissue and neoplastic proliferation (H&E magnification ×10); (b) neoplastic spindle elements, consolidated to bundles (H&E magnification ×10); (c) neoplastic elements show cellular and nuclear morphologic atypia with hyperchromic nuclei (H&E magnification ×20); (d) GFAP-positive immunohistochemical reaction (magnification ×40).
While several cases of supratentorial primary GS have been reported in literature, only eight cases with a posterior cranial fossa localization have been described so far (see Table
Clinical characteristics of primary GS cases with a posterior cranial fossa localization reported in the literature.
Case | Age/gender |
Clinical presentation | MRI features | Macro-/microscopic anatomy |
---|---|---|---|---|
1 | 62/M |
Ataxia, adiadocokinesia | Not reported | Firm tumor, with dural adhesion to the tentorium cerebelli |
2 | 71/M |
Ataxia | Multiple lesions; perifocal edema; homogenous enhancement after gadolinium injection; broad base in contact with the dura mater | Firm, hemispheric well-circumscribed tumor, adherent to the dura; the superficial portion appeared sharply demarcated from the adjacent cerebellar tissue, intralesional hemorrhage/necrosis. |
3 | 80/M |
Intracranial hypertension | Solid, homogeneously enhancing mass in the vermis and left cerebellar hemisphere; peritumoral edema causing mass effect and compression on the IV ventricle | Firm and pseudo-encapsulated lesion without attachment to pia or dura; marginal hemorrhage and intralesional necrosis |
4 | 70/F |
Intracranial hypertension | Cerebellar intra-axial lesion, with a smooth and slightly lobulated outer layer; minimal peritumoral edema; heterogeneous enhancement after gadolinium injection | Relatively well-circumscribed and firm mass with areas of necrosis and hemorrhage |
5 | 68/M |
Not reported | Not reported | Discrete lesion with GBM-like characteristics |
6 | 11/F |
Ataxia, intracranial hypertension | Irregularly enhancing lesion located in the cerebellar vermis but characterized by bilateral extension; homogenous enhancement after gadolinium injection | Firm lesions reaching the surface of the cerebellum; white, glistening with areas of hemorrhage and necrosis |
7 | 57/M |
Intracranial hypertension | Solid lesion, isointense to the brain parenchyma on T1WI, hyperintense on T2WI, peripheral homogeneous enhancement after gadolinium injection | Firm intra-axial lesion without attachment to the dura mater |
8 | 71/F |
Intracranial hypertension | Solid, homogeneously enhancing, hemorrhagic mass in the cerebellopontine cistern | Well-circumscribed mass with intralesional hemorrhage |
9 | 33/F |
Intracranial hypertension | Homogenously enhancing cortical-subcortical lesion localized on the right cerebellar hemisphere, responsible for perilesional edema and characterized by evidence of dural infiltration | Well-circumscribed and firm mass; white, glistening, with intralesional evidence of necrosis |
On CT scan, GSs tend to appear as slightly hyperdense lesions with perifocal edema and marked homogeneous contrast enhancement, whereas on T1WI and T2WI MRI sequences, they usually show low and high signals, respectively [
The in-depth immunohistochemical analysis conducted in our case expands on the pathological data previously described [
The prognosis of GSs is utterly dismal, and our case is a perfect example of how fast this tumor can progress if not adequately treated with adjuvant chemo/radiotherapy after its primary excision. Stereotactic Gamma Knife radiosurgery has been described following subtotal resections or in case of local recurrence despite an initial management with conventional radiotherapy [
The most noticeable research projects aimed at improving outcomes of GS are currently attempting to focus on new drugs with an antiangiogenesis profile [
One final note revolves around the correlation between pregnancy and brain tumors: a large retrospective case series of patients with gliomas produced by the French Glioma Study Group suggests that tumor growth accelerates in 80% of patients and grade may evolve during pregnancy, resulting in a significantly higher frequency of seizures which pose specific challenges to the treating team in terms of pharmacological choices [
The biologic explanation for tumor growth during pregnancy stems from the observation that multiple hormones and growth factors produced during fetal development also enhance the oncogenesis cascade: for instance, the production of angiogenic factors such as placental growth factor which correlates with gliomas has been widely established [
Overall, the open questions regarding the challenges of treating pregnant women with new diagnosis of gliomas revolves around (a) the decision to discourage continuation of pregnancy and when to do so, (b) what monitoring plan is more appropriate for the mother and her fetus, and (c) which chemo- and radiation therapy protocol to suggest after pregnancy. Given the relevance of this clinical scenario, the most recent systematic review concluded that a multicenter individual patient level meta-analysis collecting granular information on clinical management and related outcomes is needed to provide scientific evidence for clinical decision-making in pregnant glioma patients [
Although the posterior cranial fossa remains a rare localization for primary GS, this aggressive tumor should be considered in the differential diagnosis of meningiomas, gliomas, sarcomas, and isolated fibrous tumors, even in young patients. State-of-the-art surgical techniques such as the introduction into the surgical cavity of a probe for intraoperative ultrasound or a 30-degree angle endoscope assume particular relevance to maximize resection and minimize the risk of intraoperative blood loss and postoperative hematoma. While maximal safe resection is fundamental in the management of patients with GS, without adjuvant chemo/radiotherapy the risk of early recurrence/progression of the disease is remarkably high. The case presented here was particularly challenging given the understandable desire of our patient to carry on with her pregnancy. In fact, this situation obliged the patient, as well as each medical practitioner involved in her management, to face a series of ethical questions, where compassionate care had to take priority over clinical pragmatism.
The authors have no conflicts of interest to disclose.
The authors are grateful to Prof. Rossano Ambu (Department of Pathology, “San Giovanni di Dio” Hospital, University of Cagliari, Italy) for the valuable contribution in discussing the pathological findings and critically reviewing the design of this paper.