Are vestibular schwannomas typically surrounded by hemorrhage?

Are Vestibular Schwannomas Usually Surrounded by Hemorrhage?

No, vestibular schwannomas are not usually surrounded by hemorrhage—hemorrhagic changes occur only within larger tumors as scattered internal areas, not as surrounding features, and clinically significant intratumoral hemorrhage is exceedingly rare. 1

Typical Imaging Characteristics

Vestibular schwannomas characteristically present as solid nodular masses that are isointense on T1-weighted imaging with strong gadolinium enhancement and heterogeneously hyperintense on T2-weighted imaging. 1

Standard Appearance Features:

• The mass typically has an intracanalicular component in the internal acoustic canal, often causing widening 1
• Larger lesions protrude into the cerebellar pontine cistern 1
• Larger lesions may show scattered cystic degenerative changes and hemorrhagic areas within the tumor itself 1
• Calcifications are typically absent 1

Hemorrhage: An Uncommon Internal Feature

When hemorrhage does occur in vestibular schwannomas, it appears as scattered hemorrhagic areas within larger tumors, not as surrounding hemorrhage. 1 This is an important distinction—the hemorrhage is intratumoral (inside the tumor), not peritumoral (surrounding the tumor).

Clinical Significance of Intratumoral Hemorrhage:

Clinically significant acute intratumoral hemorrhage is exceedingly rare and represents a dramatic departure from the typical slow-growing, insidious presentation. 2

• Histologically, vascular abnormalities and microhemorrhages are nearly ubiquitous across vestibular schwannomas, but these are microscopic findings that may contribute to cystic degeneration 2
• Gross intratumoral hemorrhage causing acute symptoms has a cumulative incidence of only 0.26% after radiosurgery 3
• Only 10 published reports of spontaneous intratumoral hemorrhage existed as of 2010 4

Acute Hemorrhagic Presentation:

When acute intratumoral hemorrhage does occur, patients present dramatically differently than typical vestibular schwannomas:

• Acute onset of severe headache, vomiting, complete hearing loss, and facial weakness (versus the typical insidious progression) 2, 5
• Rapid neurologic deterioration with profound cranial nerve VII and VIII dysfunction 2, 4
• CT shows areas of increased attenuation; MRI shows T2 hypointensity corresponding to acute blood 4
• Urgent surgical resection should be strongly considered to remove risk of repeat hemorrhage and further deterioration 2, 4

Critical Pitfall to Avoid

Do not confuse the normal appearance of the vestibulocochlear nerve surrounded by hyperintense CSF on heavily T2-weighted sequences (FIESTA, CISS, DRIVE) with hemorrhage. 1 The nerve appears as a linear hypointense structure surrounded by hyperintense CSF within adjacent cisterns—this is the normal anatomic appearance, not pathologic hemorrhage.