Cerebellopontine angle mass
Updates to Article Attributes
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was changed:
Cerebellopontine angle (CPA) masses frequently occur, many of which are relatively specific for the region.
Pathology
Cerebellopontine angle masses can be divided into four groups, based on imaging characteristics:
- enhancing mass
- mass with high T1 signal on MRI
- mass with CSF intensity/density
- other masses
Alternatively, a quick mnemonic to remember the common entities affecting the cerebellopontine angle (CPA) is AMEN or SAME.
Enhancing mass
-
acoustic schwannoma:
~80% of CPA masses (mostmost common by far (~80%) -
meningioma:
~10% of CPA masses (secondsecond mostcommon (~10%) - trigeminal schwannoma
- facial nerve schwannoma
- ependymoma
- metastasis, e.g. breast, lung, malignant melanoma
High T1 signal mass
- haemorrhagic acoustic schwannoma
- neurenteric cyst: usually prepontine, but fluid may be proteinaceous and high on T1
- thrombosed berry aneurysm: often will have calcified rim, and haemosiderin staining
-
white epidermoid: rare
, and will restrict; restricts on DWI -
cerebellopontine angle lipoma: usually has the facial nerve and vestibulocochlear nerve coursing through it;
will saturatesaturates on fat suppressed sequences - ruptured intracranial dermoid: often multiple droplets
, andwith original midline lesioncan bestill often seen
CSF density mass
-
epidermoid cyst:
~5% of CPA masses (thirdthird most common (~5%) - arachnoid cyst
Other masses
Many other masses can present at or around the cerebellopontine angle. They include:
- primary melanocytic neoplasm
- neurosarcoidosis
- cholesterol granuloma
- paraganglioma
- petrous apicitis
- chondrosarcoma
- chordoma
- endolymphatic sac tumour
- pituitary adenoma
- brainstem glioma
- choroid plexus papilloma
- lymphoma
- haemangioblastoma
- ependymoma
- medulloblastoma
- dysembryoplastic neuroepithelial tumour
) - ganglioglioma (rare 3)
-</ul><p>Alternatively, a quick mnemonic to remember the common entities affecting the cerebellopontine angle (CPA) is <a href="/articles/cerebellopontine-angle-mass-mnemonic">AMEN</a> or <a href="/articles/same">SAME</a>. </p><h5>Enhancing mass</h5><ul>- +</ul><p>Alternatively, a quick mnemonic to remember the common entities affecting the cerebellopontine angle is <a href="/articles/cerebellopontine-angle-mass-mnemonic">AMEN</a> or <a href="/articles/same">SAME</a>. </p><h5>Enhancing mass</h5><ul>
-<a href="/articles/acoustic-schwannomas-1">acoustic schwannoma</a>: ~80% of CPA masses (most common by far)</li>- +<a href="/articles/acoustic-schwannoma-1">acoustic schwannoma</a>: most common by far (~80%)</li>
-<a href="/articles/meningioma">meningioma</a>: ~10% of CPA masses (second most<sup> </sup>common)</li>- +<a href="/articles/meningioma">meningioma</a>: second most<sup> </sup>common (~10%)</li>
-<li>haemorrhagic <a href="/articles/acoustic-schwannomas-1">acoustic schwannoma</a>- +<li>haemorrhagic <a href="/articles/acoustic-schwannoma-1">acoustic schwannoma</a>
-<a href="/articles/neurenteric-cyst">neurenteric cyst</a>: usually prepontine, but fluid may be proteinaceous and high on T1</li>- +<a href="/articles/spinal-neurenteric-cysts">neurenteric cyst</a>: usually prepontine, but fluid may be proteinaceous and high on T1</li>
-<a href="/articles/white-epidermoid">white epidermoid</a>: rare, and will restrict on DWI</li>- +<a href="/articles/white-epidermoid-cyst">white epidermoid</a>: rare; restricts on DWI</li>
-<a href="/articles/cerebellopontine-angle-lipoma">cerebellopontine angle lipoma</a>: usually has the <a href="/articles/facial-nerve">facial nerve</a> and <a href="/articles/vestibulocochlear-nerve">vestibulocochlear nerve</a> coursing through it; will saturate on fat suppressed sequences</li>-<li>ruptured <a href="/articles/intracranial-dermoid">intracranial dermoid</a>: often multiple droplets, and original midline lesion can be often seen</li>- +<a href="/articles/cerebellopontine-angle-lipoma">cerebellopontine angle lipoma</a>: usually has the <a href="/articles/facial-nerve">facial nerve</a> and <a href="/articles/vestibulocochlear-nerve">vestibulocochlear nerve</a> coursing through it; saturates on fat suppressed sequences</li>
- +<li>ruptured <a href="/articles/intracranial-dermoid">intracranial dermoid</a>: often multiple droplets with original midline lesion still often seen</li>
-<a href="/articles/intracranial-epidermoid-cyst">epidermoid cyst</a>: ~5% of CPA masses (third most common)</li>- +<a href="/articles/intracranial-epidermoid-cyst">epidermoid cyst</a>: third most common (~5%)</li>
-<li>-<a href="/articles/dysembryoplastic-neuroepithelial-tumour">DNET</a> (dysembryoplastic neuroepithelial tumour)</li>- +<li><a title="Dysembryoplastic neuroepithelial tumour" href="/articles/dysembryoplastic-neuroepithelial-tumour">dysembryoplastic neuroepithelial tumour</a></li>
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