Bilateral petrous apex cephaloceles: Is surgical intervention indicated?

INTRODCUTION: Petrous apex cephaloceles are characterized by herniation of Meckel’s cave into the petrous apex. An extensive review of the literature reveals 20 cases of bilateral petrous apex cephaloceles. This article reports an additional case of bilateral petrous apex cephaloceles and reviews the pertinent literature. PRESENTATION OF CASE: A 64-year-old female was referred from a primary care clinic due to longstanding headache. A non-enhanced CT scan of the brain revealed osteolytic bony lesions at the petrous apices and an empty sella. A brain MRI with contrast showed CSF-containing lesions in the petrous apices, communicating with Meckel’s cave bilaterally. The patient was managed conservatively and is currently followed up in the neurosurgery clinic. DISCUSSION: While the exact etiology remains uncertain, petrous apex cephaloceles are postulated to originate from sustained, chronic elevation of intracranial pressure. On MRI, petrous apex cephaloceles display signal intensities resembling CSF throughout all sequences. They demonstrate well-defined margins continuous with Meckel’s cave. CT scans allow further characterization, i.e. invasive erosions, of the osseous structures in patients with petrous apex cephaloceles. CONCLUSION: A thorough understanding of the petrous apex anatomy and its pathological lesions is paramount. A brain MRI remains the diagnostic imaging of choice to characterize petrous apex cephaloceles.