Pleomorphic Xanthoastrocytoma Presenting with
Intraparenchymal
and
Subdural Hematoma: Case Report

Pleomorphic xanthoastrocytomas (PXAs) are low-grade tumors of adolescents and young adults and typically associated with a favorable prognosis. [7,8,14,15] They most often become symptomatic with seizures.We report a patient with a PXA who became symptomatic with a life-threatening intracranial hemorrhage. This report is the second case of a PXA manifesting with intracranial hemorrhage and the first in which the patient survived the event.[12]

A 38-year-old woman with a long history of headaches experienced the sudden onset of a right temporal headache the day before her admission. Her level of consciousness progressively declined, and she was evaluated and intubated at an outside hospital. Computed tomography (CT) showed a large right temporal intraparenchymal hemorrhage, an acute right frontotemporal subdural hematoma, and subarachnoid hemorrhage. She was transferred to our facility for further care. She had no history of hypertension, bleeding diathesis, trauma, or illicit drug use, and her medical history was unremarkable.

On examination the patient was lethargic. Her cranial nerve examination was normal. She sluggishly followed commands. Her diminished level of consciousness precluded a detailed motor and sensory assessment. She appeared to move her extremities symmetrically.

The large nontraumatic intracranial hemorrhage prompted an angiographic evaluation for vascular lesions,but the study was negative. The right common carotid artery injection demonstrated significant round shift of the middle cerebral artery candelabra and right-to left displacement of the anterior cerebral arteries (Fig. 1). Repeat CT demonstrated progression of the subdural hematoma and enlargement of the intraparenchymal hematoma (Fig. 2) compared to the outside diagnostic films. It also showed complete obliteration of the basal cisterns with imminent herniation.

The large nontraumatic intracranial hemorrhage prompted an angiographic evaluation for vascular lesions,but the study was negative. The right common carotid artery injection demonstrated significant round shift of the middle cerebral artery candelabra and right-to left displacement of the anterior cerebral arteries (Fig. 1). Repeat CT demonstrated progression of the subdural hematoma and enlargement of the intraparenchymal hematoma (Fig. 2) compared to the outside diagnostic films. It also showed complete obliteration of the basal cisterns with imminent herniation.

A right pterional craniotomy was performed emergently. The subdural hematoma and intraparenchymal hematoma were evacuated. Upon removal of the hematoma,a nodular mass based on the floor of the temporal fossa was visible.The hematoma had surrounded this mass,which was resected with standard microsurgical techniques. The tumor itself was not vascular. No vascular injury was noted. The preliminary diagnosis was atypical meningioma. A drain was left in the subdural space.

The patient was monitored in the intensive care unit for 2 days. Postoperative CT confirmed excellent evacuation of the hematoma and resolution of the midline shift. Postoperative magnetic resonance imaging (MRI) showed no residual tumor (Fig. 3). She recovered completely and was discharged home on postoperative Day 5. She was neurologically intact and had suffered no complications.

Histology

Microscopic examination demonstrated the typical features of PXA. Hypercellularity was marked. The preponderant cell population was composed of large fibrillary astrocytes associated with only mild-to-moderate atypia. Numerous cells with large, highly atypical nuclei scattered throughout the matrix often had abundant cytoplasm with a fibrillary, homogeneous "ground glass," or vacuolated appearance. The latter two features reflected lipid accumulation. Numerous eosinophilic granular bodies were present. The tumor cells were immunoreactive for glial fibrillary acidic protein (GFAP),consistent with glial differentiation. Scattered cells were also reactive for the neuronal marker synaptophysin. No mitotic figures were present, and the MIB-1 labeling index was 1 to 3%, indicating modest proliferative activity. Neither microvascular proliferation nor tumor necrosis was present (Fig. 4).

In 1979 PXAs were defined as a unique clinicopathologic entity.[10] Their ominous histological features, including cellular pleomorphism, nuclear atypia, and presence of multinucleate giant cells,belie their benign nature. The cell of origin is uniformly the astrocyte as demonstrated by their GFAP positivity. These tumors are usually located superficially in the temporal lobe and frequently abut if not involve the dura. PXAs have been reported within the posterior hypophysis, retina, pineal gland, cerebellum,and spinal cord.[1,9,14,20] MRI shows a cystic lesion with an enhancing mural nodule.16 The radiographic differential diagnosis includes ganglioglioma and pilocytic astrocytoma.

This disease of adolescents and young adults usually manifests with seizures.[3,19] Less common symptoms and signs, which include headaches,nausea,vomiting, motor/sensory deficits, and papilledema, can be ascribed to increased intracranial pressure and regional mass effect. In fact,our patient had a long history of chronic daily headaches that had never been investigated until she sustained the massive,life-threatening hemorrhage.

The literature suggests that patients with PXA tend to have a favorable prognosis. In an early review of 35 patients with PXA,Whittle et al.19 noted almost a 50% survival rate 7.4 years after diagnosis. More recently,Pahapill et al.[15] reported an actuarial survival rate of 82% at 10 years. They found that the presence of necrosis portended a poor outcome. Fouladi et al.6 reviewed 13 pediatric patients with PXA. Ten patients were alive at 41 months, and gross total resection prolonged disease control in 85%. Finally, Giannini et al.[7] described 71 patients with PXA who had an overall survival rate of 70% at 10 years. Mitotic activity and extent of resection predicted recurrence-free survival and overall survival. Necrosis correlated significantly with the overall survival rate but not with the recurrence-free survival rate. Several reports highlight the potential for malignant transformation of PXA and provide justification for routine radiographic follow up of these patients. [2,5,17]

Hemorrhage is either a rare presentation of this tumor or is underreported. Histologically, PXAs resemble moderately
cellular astrocytic tumors and are associated with nuclear pleomorphism, multinucleated giant cells, and cystic areas containing proteinaceous fluid. The amount of reticulin-containing stroma is variable.13 PXAs are not associated with vascular endothelial proliferation. [7,13] These tumors are not typically hypervascular on microscopic examination. Why, then, did our patient suffer such a dramatic intracranial hemorrhage?

Lee et al.[11] described a single case of an arteriovenous malformation (AVM) associated with a PXA. The AVM was demonstrated on preoperative angiography. Our patient, however, had no AVM,and no portion of the histological specimen resembled the nidus of an AVM. Therefore this pathophysiology seems unlikely. Similar to hemorrhage within an arachnoid cyst, trauma can cause a vessel stretched by a tumor mass to tear. Our patient, however, had no history of trauma. An angiomatous variant of PXA with prominent vascularity has been described,[18] but microvascular proliferation was absent in our patient. PXAs have been known to invade the adjacent leptomeninges and dura.[13] Fouladi et al.[6] reported meningeal invasion in 12 of 13 patients with PXA. De Jesús et al.[4] described a recurrent PXA that invaded the tentorium and falx cerebri. Levy et al.[12] described a 46-year-old woman who developed a massive left temporal hematoma and subarachnoid hemorrhage from a PXA. She died despite evacuation of the hematoma and resection of the temporal PXA. They suggested that erosion of a cortical vessel may have been the underlying cause. In our case both the tumor mass and the subdural hematoma were primarily along the temporal floor. Ostensibly, the tumor eroded a vessel causing a hematoma that propagated to fill the cystic portion of the tumor and surrounded the mural nodule. Given the known predilection of these tumors for dural or leptomeningeal involvement, erosion of a cortical or dural vessel at the floor of the temporal fossa is the most rational explanation for our patient's presentation.

PXAs are rare astrocytic tumors that tend to manifest with seizures. Clinicians, however,must be aware that these low-grade tumors also can become symptomatic with massive intracranial hemorrhage that can pose a life-threatening risk. Timely diagnosis and surgical treatment can yield rewarding clinical results.

References

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