Synchronous Tumors of the Cerebellopontine Angle

Multiple CPA tumors are rare, heterogeneous lesions with a marked predisposition toward poor facial nerve outcomes, potentially attributable to a paracrine mechanism that simultaneously drives multiple tumor growth and increases invasiveness or adhesiveness at the facial nerve-tumor interface. Preceding nomenclature has been confounding and inconsistent; we recommend classifying all multiple CPA tumors as “synchronous tumors,” with “schwannoma with meningothelial hyperplasia” or “tumor-to-tumor metastases” reserved for rare, specific circumstances.