Hypervascular Vestibular Schwannomas: Clinical Characteristics, Angiographical Classification, and Surgical Considerations

Abstract

HVS have the distinct clinical characteristics compared with those of non-HVS subjects.

Computed tomography angiography lightbulb sign: Characteristic enhancement pattern on neck computed tomography angiography in differentiating paraganglioma from schwannoma of the carotid space

“…The schwannoma on the other hand, can sometimes demonstrate intratumoral enhancing vessels reflecting microvascular proliferation and vessel hyalinization on CTA with the "salt-and-pepper appearance" on MRI (Figure 2 (a)-(c)) but a negative CTA lightbulb sign (Figures 1 (c) and 2(d)). 2,10 To our knowledge, this study is the first study of the "lightbulb sign" on CTA of the head and neck. However, in the radiology literature, lightbulb signs have been described in other entities including hepatic hemangioma 13 and adrenal pheochromocytoma, 14 as these lesions show very bright signal intensity on T2 weight sequences reminiscent of a glowing lightbulb.…”

“…This supports previous reports describing how schwannomas with internal vascularity ("vascularized schwannoma") on CTA can give a "salt-and-pepper appearance" on MRI mimicking paraganglioma. 9,10 Furthermore, both paraganglioma and schwannomas can demonstrate similar intense enhancement on post-gadolinium MRI (Figure 2(c)) as well as on the venous phase CECT. The previous studies using neck magnetic resonance angiography (MRA) 11,12 and dynamic contrast enhanced MRI 2 have shown the potential use in distinguishing paraganglioma from other head and neck tumors.…”

“…This supports previous reports describing how schwannomas with internal vascularity (“vascularized schwannoma”) on CTA can give a “salt-and-pepper appearance” on MRI mimicking paraganglioma. 9,10…”

“…The schwannoma on the other hand, can sometimes demonstrate intratumoral enhancing vessels reflecting microvascular proliferation and vessel hyalinization on CTA with the “salt-and-pepper appearance” on MRI (Figure 2(a)–(c)) but a negative CTA lightbulb sign (Figures 1(c) and 2(d)). 2,10…”

Prediction of blood supply in vestibular schwannomas using radiomics machine-learning classifiers

“…The blood supply of VS is an important factor affecting the di culty of surgery. Previous studies have reported on Hypervascular Vestibular Schwannomas [5][6][7][8], and several studies have shown that an abundant blood supply is signi cantly leading to an occurrence of facial impairment [9] and decrease of rate of resection [8]. The current method of preoperative assessment of the blood supply in VS is mainly by visual identi cation of the anatomical presentation of MRI and the degree of signal enhancement on T1-CE sequences.…”