Synchronous Tumors of the Cerebellopontine Angle.
BACKGROUND
Synchronous tumors of the cerebellopontine angle (CPA) are very rare and inconsistently described. We present 2 cases of contiguous vestibular schwannoma (VS) and meningioma and a systematic literature review of all multiple CPA tumors.


METHODS
Retrospective chart review and systematic literature review were performed.


RESULTS
A 64-year-old woman and a 42-year-old man presented with symptoms referable to the CPA. Magnetic resonance imaging in both patients revealed 2 separate contiguous tumors. Retrosigmoid craniotomy and tumor removal in each case confirmed VS and meningioma. Systematic literature review identified 42 previous English-language publications describing 46 patients with multiple CPA tumors. Based on Frassanito criteria, there were 4 concomitant tumors (8%), 16 contiguous tumors (33%), 3 collision tumors (6%), 13 mixed tumors (27%), and 11 tumor-to-tumor metastases (23%). Extent of resection was gross total in 16 cases and subtotal in 16 cases (50% each). Unfavorable House-Brackmann grade III-VI function was documented in 27% overall and in 33% of patients with VS and meningioma, a marked increase from the observed range in isolated VS.


CONCLUSIONS
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.
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Christopher S
CS
Graffeo
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Avital
A
Perry
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
William R
WR
Copeland
Department of Pathology and Laboratory Science, Mayo Clinic, Rochester, Minnesota, USA.
Caterina
C
Giannini
Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Brian A
BA
Neff
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA; Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Colin L W
CL
Driscoll
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA; Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: Link.Michael@Mayo.edu.
Michael J
MJ
Link
D000328:Adult; D002528:Cerebellar Neoplasms / Q000473:pathology* / Q000601:surgery; D002530:Cerebellopontine Angle; D003399:Craniotomy / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology* / Q000601:surgery; D008579:Meningioma / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology* / Q000601:surgery; D009464:Neuroma, Acoustic / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies
Cerebellopontine angle; Collision tumor; Contiguous tumor; Meningioma; Mixed tumor; Tumor-to-tumor metastasis; Vestibular schwannoma