Juvenile anaplastic hemangiopericytoma of cavernous sinus.

Dear Sir,

An 11-year-old boy had headache and diplopia for distal objects for 3 months. He developed gradually progressive ptosis of left eye and right hemiparesis for 1 month prior to presentation. He was brought in status epilepticus to emergency department. Magnetic resonance imaging (MRI) scan of the brain revealed an extra-axial mass, measuring 8.9 × 6.6 × 5.7 cm lobulated, attached to the cavernous sinus. It had completely encased the cavernous part of left internal carotid artery. The mass had grown superiorly compressing the overlying brain, ipsilateral lateral ventricle, and the left cerebral peduncle. On T1-weighted images, the mass appeared iso- to hypointense to cortical gray matter [Figure 1a]. On T2-weighted images, the mass had heterogeneous intensity with cystic changes and areas of hypointensities. In contrast, the mass showed intense heterogeneous enhancement with multiple flow-voids. There was hydrocephalus with shift of midline to the right [Figure 1b–e]. On fluid attenuation inversion recovery (FLAIR), the mass was isointense with the gray matter [Figure 1f]. The patient was subjected to left temporobasal craniotomy. In the middle fossa, the tumor was entirely within the dural covering of the cavernous sinus, and widened Meckel's cave. Tumor was highly vascular and heterogeneous in consistency with areas of necrosis. The tumor became intradural into the posterior fossa after coming out of Meckel's cave with arachnoid capsule surrounding it. The posterior fossa component of the tumor was removed after cutting tentorium posterior to the trochlear nerve. The tumor in relationship with the brainstem was covered by a relatively thick arachnoid membrane, making the tumor resection relatively safe. The trigeminal nerve was displaced along the lateral dome of the tumor. Skull base repair was done using the locally available temporalis muscle, fat, and fascia lata grafts harvested from right thigh. Unfortunately, patient had stormy postoperative course with pneumonitis and septicemia. He expired due to septicemia after two days. Histopathology showed sheets of plump spindloid cells and dilated gaping stag horn vasculature with anaplastic cells and foci of necrosis, consistent with the diagnosis of anaplastic hemangiopericytoma [Figure 2a and b].

Figure 1

(a) T1-weighted axial image. (b) T2-weighted axial image of the brain, showing an extra-axial lobulated mass arising from left cavernous sinus compressing the overlying brain, lateral ventricle, and the left cerebral peduncle. (c) T1-weighted contrast-enhanced sagittal image. (d) T1-weighted contrast-enhanced axial image. (e) T1-weighted contrast-enhanced coronal image of the brain, showing intense heterogeneous enhancement within the mass with multiple flow-voids. (f) On fluid attenuation inversion recovery (FLAIR), the mass was isointense with the gray matter

Figure 2

(a) Photomicrograph (H and E, ×100) showing sheet of plump spindloid cells and dilated gaping stag horn vasculature with anaplastic cells. (b) Photomicrograph (H and E, ×100) showing cellular necrosis

Intracranial hemangiopericytomas are neoplasms of pericytes that originate in the meninges, which commonly occur in the fourth and fifth decades of life.[12] These are dural-based hyper vascular masses resembling meningiomas on imaging; however, histologically these are not meningiomas. Hemangiopericytomas are more aggressive, tend to recur even after gross total resection, and occasionally have extra cranial metastases to bone, lung, liver, kidney, pancreas, and adrenals.[1-3] On imaging, diagnosis is not simple, intracranial hemangiopericytomas are multilobulated, extra axial tumors, sometimes associated with narrow based dural attachment and bone erosion. Unlike meningiomas, hyperostosis and intratumoral calcification are not present.[4] Differential diagnoses of such lesions include meningiomas, gliosarcomas, metastases, lymphoma, and primitive neuroectodermal tumors.[13] Three cases of hemangiopericytomas of cavernous sinus have been reported in adults.[2] Few cases of intracranial hemangiopericytomas in pediatric age group have also been reported in literature.[4] None of these was involving the cavernous sinus. Our case is the first of its kind in pediatric age group. Treatment protocol includes surgery followed by radiotherapy with or without chemotherapy. Chemotherapeutic agents like vincristine, doxorubicin, and cyclophosphamide have been tried owing to high chemo responsiveness of these tumors.[134]

Anaplastic hemangiopericytoma should be considered in differential diagnosis of a heterogeneous lesion of cavernous sinus presenting with short duration of symptoms.