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Cerebellopontine angle mass

contributed by Dr Frank Gaillard on May 2, 2008

System: Central Nervous System
Section: Gamuts

A quick mnemonic to remember the common entities affecting the CPA is AMEN.

Enhancing mass
  1. acoustic schwannoma
  2. meningioma
  3. trigeminal schwannoma
  4. ependymoma
  5. metastasis
High T1WI signal mass
  1. haemorrhagic acoustic schwannoma
  2. neurenteric cyst : usually prepontine, but fluid may be proteinaceous and high on T1
  3. thrombosed berry aneurysm : often will have calcified rim, and haemosiderin staining.
  4. white epidermoid : rare, and will restrict on DWI
  5. cerebellopontine angle lipoma : usually has the facial nerve and vestibulocochlear nerve coursing through it. Will saturate on fat suppressed sequences.
  6. ruptured intracranial dermoid : often multiple droplets, and original midline lesion can be often seen.
CSF density mass
  1. epidermoid cyst
  2. arachnoid cyst
Other masses that can present in the cerebellopontine angle
  1. primary melanocytic neoplasm
  2. neurosarcoid
  3. cholesterol granuloma
  4. paraganglioma
  5. petrous apicitis
  6. chondrosarcoma
  7. chordoma
  8. endolymphatic sac tumour
  9. pituitary adenoma
  10. brainstem glioma
  11. choroid plexus papilloma
  12. lymphoma
  13. haemangioblastoma
  14. ependymoma
  15. medulloblastoma
  16. DNET (Dyembroblastic neuroepithelial tumour)