Petrous apex cephalocoele

Petrous apex cephalocoele (PAC) is a rare form of cephalocoele centered typically in the posterolateral part of Meckel cave with variable extension into the petrous apex. They can be unilateral or bilateral (commoner).

There may be a slight female predilection.

The lesions are incidentally detected and are asymptomatic most of the times. Though they may present with trigeminal neuralgia, headache, CSF otorrhea, and sensorineural hearing loss.

Recognized associations include

  • homogenously low density area is noted in the petrous apex with sharply defined margins

MRI can demonstrate the continuation with Meckel cave and hence helps in providing a confident diagnosis thereby preventing unnecessary surgical intervention. The signal intensities follow that of CSF.

  • T1: hypointense
  • T2: hyperintense
  • FLAIR: typical CSF suppression 
  • DWI: no restriction

As a general differential consider


Article information

rID: 28262
Tag: stub, refs, cases
Synonyms or Alternate Spellings:
  • Petrous apex cephalocoeles
  • Petrous apex cephalocele
  • Petrous apex cephaloceles
  • Petrous apex cephalocoele (PAC)
  • Petrous apex cephalocoeles (PAC's)

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Cases and figures

  • Case 1
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  • Observed cystic a...
    Case 2
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