Right petrous apicitis (Gradenigo's syndrome clinically)

Findings

CT shows an expansile, destructive lesion in the right petrous apex, which is bright on T2 weighted MR images, and has an enhancing soft tissue component on post contrast T1 weighted-images.

Differential diagnosis:
- Petrous apicitis
- Cholesterol granuloma
- Trapped fluid
- Chondrosarcoma
- Cholesteotoma
- Lymphoma


Diagnosis: Right petrous apicitis (Gradenigo's syndrome clinically)


Key points

Synonyms for petrous apicitis include apical petrositis and confluent apical petrositis.
Petrous apicitis typically occurs via spread of infection from mastoids through air cells into petrous apex.
Clinical presentation is variable; most have otorrhea and pain. Patients can have cranial neurophaties.
In kids, petrous apicitis is often a sequelae of acute otomastoiditis. In adults, it is more often due to chronic infection.
Gradenigo's syndrome is acute otomastoiditis, trigeminal (CN 5) nerve neuritis, and Abducens (CN 6) palsy (CN 6 controls the lateral rectus muscle).
Temporal bone CT and MRI are the best imaging modalities for making the diagnosis.
On CT, findings of petrous apicitis include a destructive lesion with both cortical and trabecular loss in the petrous apex.
The best clue to diagnosis is trabecular destruction in an opacified petrous apex, which is best appreciated on CT.
On MR, findings of petrous apicitis are a thick walled, enhancing area of soft tissue with fluid in the petrous apex.
Nuclear medicine Gallium-67 scan with SPECT can improve the sensitivity for disease detection and can be used to monitor response to treatment.
Petrous apicitis was a common, severe and life-threatening infection in the pre-antibiotic era. It is now relatively uncommon.
Inflammation/infection from the petrous apex can spread to meninges and cause meningitis or can lead to cavernous thrombosis.
Treatment requires antibiotics and often surgical drainage.