Hematoma in a low-grade medullary astrocytoma: report of an unusual case and literature review

Abstract

We describe the case - to our knowledge unique - of an 8-year-old boy who presented with acute onset of lower cranial nerve palsy and tetraparesis caused by a hematoma in a dorsal exophytic pilocytic astrocytoma of the medulla oblongata. The boy showed near-complete recovery after neurosurgical management in two stages: first, emergency evacuation of the hematoma with tumor biopsy, and second, complete tumor removal 5 months after the initial event. Intraoperative electrophysiological monitoring techniques for the lower cranial nerves are of value in preserving their functional integrity. Ultrasonography is helpful in assessing the extent of tumor removal. Although the pathological diagnosis of a pilocytic astrocytoma would not justify radiotherapy, local field radiotherapy was added mainly because of the unexpectedly rapid tumor progression during the interval between the two surgical procedures. The literature on brainstem and tumor hematoma in children is reviewed.

Pilomyxoid Astrocytoma: Expanding the Imaging Spectrum

“…[18][19][20][21][22][23][24][25][26][27][28] Until recently the rate of hemorrhage in PA was estimated at Ͻ1%. However, a recent retrospective series of 134 patients with a tissue diagnosis of PA found an 8% spontaneous hem- orrhage rate, much higher than that previously reported.…”

Total Resection of a Hemorrhagic Tectal Pilocytic Astrocytoma-Case Report-

“…A medullary pilocytic astrocytoma including oligodendrogliotic parts in a child manifested as acute onset of symptoms caused by an intratumoral hematoma. 17) They suggested that hematomas might originate from abnormal fragile vasculatures in oligodendrogliotic parts of the tumor or occult coexisting Neurol Med Chir (Tokyo) 47, May, 2007 Hemorrhagic Tectal Pilocytic Astrocytoma vascular malformations. Hemorrhage in pilocytic astrocytomas can be attributed to vascular proliferation, which is an occasional feature of these tumors.…”

“…Hemorrhage is an infrequent presentation for pilocytic astrocytoma, although pilocytic astrocytoma was reported as the cause of fatal intracranial hemorrhage in a few cases. 4,6,11,17,19) Various theories for the etiology of intratumoral hemorrhage have been proposed as follows: Endothelial proliferation with vascular obliteration, vessel compression and/or distortion as a result of rapid growth, vessel necrosis, invasion of a vessel wall by the tumor, and increased venous pressure associated with raised intracranial pressure or thinwalled vessels. 9) However, the cause of hemorrhage in low-grade glioma is not well known.…”

Massive Intracranial Hemorrhage Associated With Pleomorphic Xanthoastrocytoma -Case Report-

“…10) Only a few cases of hemorrhage associated with lowgrade astrocytomas have been reported. 2,4,5,14,17,20) Possible causes of intratumoral hemorrhage include endothelial proliferation with vascular obliteration, vessel compression and/or distortion due to rapid tumor growth, vascular necrosis, abnormal structure of tumor capillaries such as retiform capillaries, and invasion of vessel walls by the tumor. 7,13,16,20) However, which histological features and what mechanisms actually cause such bleeding remain unclear.…”

“…2,4,5,14,17,20) Possible causes of intratumoral hemorrhage include endothelial proliferation with vascular obliteration, vessel compression and/or distortion due to rapid tumor growth, vascular necrosis, abnormal structure of tumor capillaries such as retiform capillaries, and invasion of vessel walls by the tumor. 7,13,16,20) However, which histological features and what mechanisms actually cause such bleeding remain unclear. 4) In the first reported case of intracerebral and subarachnoid bleeding from a pleomorphic xanthoastrocytoma, temporal lobe and adjacent meningeal involvement by the neoplasm was proposed to have eventually produced erosion of an artery on the surface of the brain, but the cause of bleeding was not identified by imaging such as angiography.…”