Neuroimaging Features of Optic Nerve Hemangioblastoma Identified by Conventional and Advanced Magnetic Resonance Techniques: A Case Report and Literature Review

Optic nerve hemangioblastoma is a very rare benign tumor with only 39 reported cases by now. It appears to be hyperintense on T2-weighted images with a significant enhancement on contrast scans, which are similar to glioma and meningioma. Due to the lack of specificity in MRI manifestations, optic nerve hemangioblastoma is often misdiagnosed. To provide new insights into differential diagnosis of optic nerve hemangioblastoma, we report for the first time an optic nerve hemangioblastoma case employing advanced magnetic resonance techniques including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, and magnetic resonance angiography (MRA). In addition, we have collected all reported optic nerve hemangioblastoma cases and reviewed their neuroimaging findings by MRI and angiography. Our results show that solid-type tumor is the dominant form of optic nerve hemangioblastoma and extensive edema is widely observed. These findings are surprisingly contrary to manifestations of cerebellar hemangioblastoma. Besides the structural features, quantitative indexes including ADC and relative cerebral blood volume (rCBV) ratio, which are significantly elevated in cerebellar hemangioblastoma, may also shed a light on the preoperative diagnosis of hemangioblastoma of optic nerve. Finally, we discuss the critical neuroimaging features in the differential diagnosis between optic nerve hemangioblastoma from optic pathway glioma and optic nerve sheath meningioma.

Optic Nerve Hemangioblastoma: Review

BACKGROUND

Hemangioblastomas of the optic nerve are very rare tumors. They occur in association with Von Hippel-Lindau (VHL) syndrome; however, sporadic occurrences have been reported. We describe here a case of optic nerve hemangioblastoma in the absence of VHL and review the pertinent literature.

CASE DESCRIPTION

A 33-year-old woman presented with gradually progressive vision loss in the right eye. On examination, the visual acuity on the right was hand movement close to face in all quadrants. Color discrimination was impaired. Fundoscopy revealed optic atrophy and no other retinal pathology. There was relative afferent pupillary defect in the right eye. No neurocutaneous markers were found. Imaging revealed lesion isointense on T1, hyperintense on T2/fluid-attenuated inversion recovery, and showing relatively homogenous enhancement on postcontrast study. Multiple flow voids were seen in the intracranial part of the lesion. The proximal part of the intraorbital right optic nerve was enlarged and tortuous with distended optic nerve sheath. A right single-piece fronto-orbital craniotomy was done. A reddish lesion seen involving the right optic nerve just proximal to the chiasm with multiple vessels and a distinct feeding vessel was seen supplying the tumor. The lesion was excised and the optic nerve was sacrificed approximately 1 cm proximal to the chiasm. The postoperative course was uneventful.

CONCLUSIONS

Conclusions: Optic nerve hemangioblastoma is a rare occurrence and a high level of suspicion is required preoperatively in the absence of VHL syndrome.