Contributed by
Cincinnati Children's Hospital & Medical Center
Bhagyashree Rathore, James Leach, Blaise Jones, Bernadette Koch, Marguerite Care, and Betul Derinkuyu.
History
15 year old female with worsening right sided ear pain, jaw pain and headaches since 9 days.
Images (Click any image to enlarge)
Question
What is the most likely diagnosis for right petrous apex findings?
Your answer
Please log in to see your results.
Correct answer
Petrous apicitis
Discussion
Imaging Findings:
Bone window CT images (A, B) demonstrate an expansile lesion in right petrous apex with tympano-mastoid opacification.
On contrast CT images (C, D), there is decreased caliber of the adjacent petrous and cavernous segments of the right internal carotid artery. Also note, no enhancing soft tissue component in the petrous apex lesion.
On diffusion weighted images (E), there is true diffusion restriction in right petrous apex.
Additional MRI images (Image 1) of petrous apex lesion showing layering contents (pink arrow). On post contrast T1 images there is peripheral enhancement (yellow arrow). The adjacent carotid wall thickening and luminal narrowing is also demonstrated (green arrow).
Sequential follow up MRI/MRA images demonstrate improving caliber of the right internal carotid artery (image 2) and decreasing petrous apex diffusion restriction (image 3).
Petrous apicitis
- Petrous apicitis is a rare complication of otitis media.
- Gradenigo's triad of otorrhea, retro-orbital pain and abducens nerve palsy has been reported in up to 20% cases.
- Common reported symptoms include hearing loss, facial weakness and vertigo.
- Inflammation can extend to adjacent structures including V-VIII cranial nerves, carotid artery, cavernous sinus, meninges and orbital apex.
- Treatment options include medical management with antibiotics, with severe cases requiring surgical drainage.
Differential diagnosis
- Petrous apex cholesteatoma is another differential for expansile petrous apex lesion with associated diffusion restriction. This however is not associated with surrounding inflammation and carotid spasm. Congenital cholesteatomas are slow growing lesions and usually present with mass effect on adjacent structures. This does not fit the clinical presentation.
- Langerhans Cell Histiocytosis can also present as expansile petrous apex lesion, however it typically does not demonstrate diffusion restriction, has a more enhancing soft tissue component and does not cause carotid spasm.
- Cholesterol granuloma also does not show diffusion restriction or surrounding inflammation. It is an expansile lesion of petrous apex and can have intrinsic T1 hyperintense contents.
- Petrous apex effusion is a relatively frequent finding in which petrous appears T1 hypointense and T2/FLAIR hyperintense. This is not expansile and does not show diffusion restriction.
Additional images
References
- Chapman, Philip R., et al. "Petrous apex lesions: pictorial review." American Journal of Roentgenology 196.3_supplement (2011): WS26-WS37.
- Talmor, Guy, et al. "Petrous apicitis: a systematic review and case presentation." Otology & Neurotology 43.7 (2022): 753-765.
- Isaac, Heba, et al. "Transmastoid and transtemporal drainage of petrous apicitis with otitis media." Annals of Otology, Rhinology & Laryngology 130.3 (2021): 314-318.