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76-Year-Old Female with Dizziness
This case features a 76-year-old female presenting with dizziness, ultimately diagnosed with a petrous apex cephalocele.
Imaging overview:
Axial non-contrast CT in soft tissue and bone windows demonstrates smooth remodeling of the anterior petrous apex with fluid density, contiguous with Meckel’s cave. Axial CISS MRI confirms CSF signal intensity within the petrous apex lesion and clearly delineates its continuity with Meckel’s cave, characteristic of a petrous apex cephalocele.
Clinical insight:
Petrous apex cephaloceles are CSF-containing expansions of Meckel’s cave into the petrous apex, formed by smooth remodeling of the adjacent bone. They are most commonly asymptomatic and discovered incidentally, though rare presentations include CSF otorrhea and meningitis. CISS or other heavily T2-weighted MRI sequences are the preferred modality for characterization, clearly demonstrating the fluid signal and continuity with Meckel’s cave. Petrous apex cephaloceles may be associated with idiopathic intracranial hypertension (IIH), and correlation with other imaging findings of IIH should be considered when this diagnosis is encountered.
Case courtesy of Daniel E. Meltzer, MD, Mount Sinai Hospital System, NYC.