Sporadic hemangioblastoma of cauda equina: An atypical case report.

BACKGROUND: Hemangioblastomas account for about 1%-3% of all central nervous system tumors. They are usually associated with the Von Hippel-Lindau syndrome and typically occur in the posterior fossa, or throughout the spinal neuraxis. Here, we report the unusual case of a sporadic cauda equina hemangioblastoma. CASE DESCRIPTION: A 28-year-old Caucasian female patient presented with progressive low back pain of 2 months duration. The magnetic resonance (MR) revealed a heterogeneous intradural and extramedullary lesion at the L2 level; with intravenous contrast, there were vascular flow voids and surrounding vasogenic edema (i.e., measuring 4.1 cm × 3.5 cm). The patient underwent an L2 right hemilaminectomy under intraoperative neurophysiological monitoring. She was discharged the 4th postoperative day, neurologically intact. Literature describes 21 previous reports of sporadic isolated spinal hemangioblastomas.
CONCLUSION: Although rare, sporadic, and isolated hemangioblastomas of the cauda equina should be included among the differential diagnoses of intradural spinal lesions, particularly when enhanced MR studies document serpentine flow voids.

INTRODUCTION

Hemangioblastomas account for about 1%–3% of all central nervous system tumors.[1] They are usually associated with the Von Hippel–Lindau syndrome and are mainly found in the posterior fossa or throughout the spinal neuraxis.[1-5] They are typically seen in an intradural/intramedullary rather than intradural/extramedullary location.[4] Only 21 such cases of extramedullary hemangioblastomas of the cauda equina without Von Hippel–Lindau syndrome had been previously reported.[1] Here, we report yet another such case with literature review.

CASE DESCRIPTION

A 28-year-old Caucasian female presented with progressive low back pain of 2 months duration. She had no significant medical history and exhibited no focal neurological deficits. The magnetic resonance imaging (MRI) of the lumbar spine revealed a heterogeneous intradural/extramedullary lesion at the L2 level (measuring 4.1 cm × 3.5 cm) that enhanced with contrast. Flow voids were also demonstrated along with surrounding vasogenic edema [Figure 1]. Differential diagnoses included arteriovenous malformations, cavernous malformations, and/or other highly vascular lesions (e.g., hemangioblastomas).

Figure 1:

Magnetic resonance images. Above, sagittal T2 images and below, T1 images revealing gadolinium enhancement of L2 lesion.

Surgery

An L2 right hemilaminectomy was performed utilizing intraoperative neuromonitoring [Figure 2]. A richly vascularized tumor was identified on opening the dura. There was a clear cleavage plane between the tumor and the filum terminale, facilitating full resection. The patient was discharged home on the 4th postoperative day without a neurological deficit.

Figure 2:

Above, L2 hemilaminectomy. Below, after dural sac opening and visualization of cauda equina roots and tumor fragments.

Pathology

Hematoxylin and eosin stains revealed a highly vascular and cellular tumor [Figure 3]. The immunohistochemical examination showed the presence of inhibin. The tumor was CD34 positive and showed a rich vasculature. Together these results were diagnostic for a hemangioblastoma.

Figure 3:

Histology image. In (a) and (b), hematoxylin-eosin images of hemangioblastoma. In (c), immunohistochemistry signaling with inhibin. In (d), immunohistochemistry signaling with CD34.

DISCUSSION

Isolated tumors of the cauda equina represent 10% of all spinal canal lesions and typically include schwannomas, meningiomas, or ependymomas. Hemangioblastomas appear isointense on T1 and hyperintense on T2 MRI scans and/or heterogeneous hyperintensity on T2 studies secondary to flow voids attributed to their high vascularity (e.g., serpentine/tortuous/convoluted vessels).[1-5]

For the total of 22 cases of filum terminal hemangioblastomas (e.g., including this case), patients averaged 51 years of age [Table 1]. Notably, half of these tumors involved the cauda equina, and the other half, the filum terminale. In the majority of cases, patients exhibited sensory symptoms and neurological deficits postoperatively, these complaints typically improved.[1]

Table 1:

Data of patients with spinal hemangioblastomas.

Surgical resection of these lesions is considered safe and effective with low accompanying complication/morbidity rates (e.g., few significant postoperative neurological deficits).