Vestibular schwannomas, also known as acoustic neuroma, are benign neoplasms of the vestibulocochlear nerve sheath and are the most common cerebellopontine angle (CPA) tumor. 

Contrast-enhanced CT can serve as an alternative if the patient cannot undergo MR imaging ¹. MR imaging is the preferred technique and plays a significant role in tumor characterization, surgical planning, and post-therapeutic evaluation ^1,2. Contrast is essential because a non-enhanced study can miss small tumors.

In the present case, MR images show evidence of the slow growth of this schwannoma, including the smooth expansion of the IAC, with osseous remodeling, deformation of adjacent brain tissue, and a disproportionately small amount of edema, given the size of some this tumor. 

On T2-weighted images, this schwannoma appears heterogeneously hyperintense, probably due to regions of compactly arranged cells (Antoni A) mixed with regions of sparsely arranged cells (Antoni B), with variable cellularity and water content.

Concerning features include larger size, brain stem or cerebellar compression, peritumoral edema, hydrocephalus, and tonsillar herniation ¹.

Tissue sampling of this tumor revealed schwannoma - pathology-proven vestibular schwannoma.

Case courtesy

• Erick Cavalcante, MD - PGY-3, Radiology Resident, Department of Radiology
• Antonio Rodrigues de Aguiar Neto, MD - Radiologist, Department of Radiology
• Hospital da Restauração – Recife, PE – Brazil