Hemorrhagic onset of cerebellar pilocytic astrocytoma in an adult: a case report and review of the literature implying a possible relation of degenerative vascular changes to the massive intratumoral hemorrhage

Abstract

Pilocytic astrocytoma (PA) is a low-grade astrocytic tumor arising predominantly during the first two decades of life. Hemorrhagic onset of PAs is uncommon, and the etiology of hemorrhage remains unclear. Here we report a case of hemorrhagic onset of cerebellar PA in a 29-year-old man who presented with a week-long history of headache and gait instability. Computed tomography and magnetic resonance imaging revealed a hemorrhagic tumor located in the right cerebellar hemisphere, and total resection was performed. Histological examination showed bipolar glial cell proliferation in a biphasic pattern in a compact area and a loose microcystic area with Rosenthal fibers and eosinophilic granular bodies, indicating PA. Prominent changes in tumor vasculature, including aggregation of sclerotic thick-walled and ectatic thin-walled vessels, was observed, and nodules of thrombi containing complex vascular proliferation suggesting recanalized thrombi formed in partially ruptured vessels were also found. Thus, rupture of these abnormal vessels appeared to be the cause of hemorrhage. Review of the literature revealed that age distribution of patients with hemorrhagic PAs tends to be older than that of patients with general PAs. These findings imply a possibility that degenerative changes in blood vessels in long-standing PAs might be related to the mechanisms of spontaneous intratumoral hemorrhage.

Spontaneous hemorrhages in pediatric supratentorial pilocytic astrocytomas. Malignant presentation of a benign entity

“…These vessels, despite being rich in collagen, have less of elastic fibers and less compliance. This added by high vascularity of tumor makes them prone to rupture [14]. The vessels in this tumor are thin walled and have reticular capillary structure.…”

Manifestations of pilocytic astrocytoma: a pictorial review

“…Progression of residual disease can be controlled by tumour re-excision and stereotactic radiosurgery [27, 28]. In the event of biopsy-proven pilocytic astrocytoma with anaplastic features, radiation therapy and/or chemotherapy will be required [12]. …”

Acute Neurological Deterioration in an Adult with a Cerebellar Pilocytic Astrocytoma Accompanied by Intratumoral Hemorrhage, Subdural Hematoma, and Obstructive Hydrocephalus

“…Hwang, et al described a case of a 34-year-old man presenting with a hemorrhagic hypothalamic pilocytic astrocytoma [3]. Oka, et al reported on a 21-year-old man with a tectal pilocytic astrocytoma presenting with hemorrhage [9]. Lee, et al…”

“…Rupture within areas of this abnormal vasculature may be the etiology behind intratumoral hemorrhage of pilocytic astrocytomas. It has also been implied that some degree of degenerative vascular changes may be the underlying factor ultimately leading to hemorrhage, given the older age distribution of patients with hemorrhagic pilocytic astrocytomas [9].…”

“…We aim to present the case of an adult harboring a posterior fossa pilocytic astrocytoma presenting in an acute fashion with a rapidly deteriorating neurological exam after spontaneous intratumoral hemorrhage. Cases of hemorrhagic presentation of these tumors have been reported in the literature [1][2][3][4][5][6][7][8][9][10][11], although they are quite rare. The vast majority of pilocytic astrocytomas are not associated with hemorrhage, leading one to infer that a small sub-population of these tumors may have inherent features making them more susceptible to hemorrhagic complications.…”