Intralabyrinthine Schwannomas: Imaging Diagnosis and Classification

Abstract

BACKGROUND AND PURPOSE: ILS is a rare lesion that has a different management from the more common "acoustic" schwannoma. To date, only 137 cases have been reported. We present a classification scheme based on labyrinthine anatomy to describe and localize these lesions. Treatment and prognosis hinge on the appropriate localization of these tumors; thus, a concise terminology that can be used by both the otolaryngologist and radiology communities is desirable.

“Canalolabyrinthine Schwannoma,” A Rare Variant of Intralabyrinthine Schwannoma: A Case Report

“…Conversely, the lesion becomes slightly more intense than the normal fluid in unhenanced T1-weighted images [9] . After GBCA injection, however, homogeneous contrast enhancement of the labyrinthine structures is observed [6] .…”

“…In our case, serial MRI revealed no significant growth over 3 years of follow-up. Surgery is advisable in case of tumor growth as well as in case of ILS that develops inside the internal ear canal (transmacular, transmodiolar, or transotic) if patients experience intractable vertigo symptoms [6] . The transotic approach would be preferred because of the implication of cochlea.…”

“…Further, only 3 of 800 patients who had suggestive symptoms of Meniere's disease and who underwent magnetic resonance imaging (MRI) were found to have ILS (prevalence of 0.4%) [5] . Salzman et al [6] analyzed 45 cases of ILS confirmed by MRI that were collected over 14 years. Interestingly, they showed that the diagnosis of ILS diagnosis is actually more common than that thought previously.…”

Еndoscopic possibilities of the acoustic schwannomas removal in internal auditory canal

“…Вступ. Акустичні невриноми беруть початок з нейролемоцитів (шванівських клітин) мієлінової оболонки ПЗН або його гілок, з так званої зони Оберштейнера-Редліха, розташованої на рівні або медіальніше ВСХ [1][2][3][4]. Часто (більш ніж у 55% спостережень) пухлини досягають значних розмірів, тому визначити зону росту пухлини неможливо [5,6].…”

The CT and Magnetic Resonance Imaging Features of Transotic Schwannoma: A Case Report

“…It most commonly arises near the fundus of the IAC at the Schwann cell-glial junction, but can be also found anywhere along the nerve from the IAC to the terminal ends of the vestibulocochlear nerve, within the vestibule, cochlea, and semicircular canals (1,2). Intralabyrinthine schwannoma, an uncommon tumor with the likely underestimated incidence rate, develops from the Schwann cells of the intralabyrinthine branches of the vestibulocochlear nerve (1,2). Recently, the imaging identification of intralabyrinthine schwannoma has increased along with the use of the higher field magnets and the evolving magnetic resonance (MR) imaging sequences.…”