SECTION EDITOR: C. DOUGLAS PHILLIPS, MD
Diagnosis: Intralabyrinthine schwannomas (ILS)
Intralabyrinthine schwannomas are benign nerve sheath tumors that arise from perineural Schwann cells and envelop the branches of the vestibulocochlear nerve within the cochlea, vestibule, and/or semicircular canals.1 Patients with ILS may present with hearing loss, vertigo, or tinnitus separately or in combination. Based on temporal bone examinations, the prevalence of ILS has been estimated to be between 0.1% and 0.4%.1,2 Intralabyrinthine schwannomas may account for 10% of all vestibular schwannomas in centers specializing in temporal bone imaging.2 Growth characteristics are not well defined; however, Tieleman et al2 demonstrated radiologic growth in 16 of 27 patients (59%) who were followed up with MRI. High-resolution MRI remains the criterion standard in the diagnosis of vestibular schwannomas.
Radiology Quiz Case 3: Diagnosis. Arch Otolaryngol Head Neck Surg. 2011;137(8):827–828. doi:10.1001/archoto.2011.125-b