• It’s a benign tumor
• Arising from the schwann cells of the vestibular division of the 8th cranial nerve (vestibulocochlear nerve).
• Location: Cerebellopontine angle, where the vestibulocochlear nerve exits the brainstem.
• Bilateral acoustic neuromas are a hallmark feature of Neurofibromatosis Type 2 (NF2), caused by mutations in the NF2 gene encoding the merlin protein.
Histopathological finding:
• Antoni A (densely packed cells) and Antoni B areas (loosely packed cells)
• Verocay bodies: Nuclear palisading (nucleus arranged in a row)
Diagnosis:
• MRI with gadolinium contrast (Ice cream cone sign)
Mnemonic:
A = A lot of cells (densely packed cells)
B = Blank (loosely packed cells)
Disorders associated to NF2 gene (Chr-22) mutation:-
• Acoustic neuroma
• Ependymoma
• Meningioma: Dural tail sign, Psamoma bodies