Question

A patient presents with ear discharge. A CT scan of the brain is shown depicting a ring-enhancing lesion. What is the most likely diagnosis?

• A. Cerebellar abscess
• B. Temporal lobe abscess
• C. Extradural abscess
• D. Meningitis

Hint:

Ear discharge with an intracranial ring-enhancing lesion -- consider which lobe is anatomically closest to the middle ear.

Answer 1

The Correct Option is B

Step 1: Establish the clinical context.
The patient has ear discharge, which indicates chronic suppurative otitis media (CSOM) or otitis media with complications. CSOM is the most common cause of intracranial suppurative complications.

Step 2: Identify the likely intracranial complication.
The most common intracranial complications of middle ear infections in order of frequency are: meningitis, brain abscess (temporal lobe or cerebellar), extradural abscess, subdural empyema, and lateral sinus thrombosis.

Step 3: Localise the abscess based on anatomy.
Middle ear infection spreads most directly to the temporal lobe above the tegmen tympani (the thin bony plate separating the middle ear from the middle cranial fossa). Temporal lobe abscesses frequently arise from middle ear mixed bacterial infections with large numbers of anaerobes. The CT image shows a ring-enhancing lesion in the temporal lobe region.

Step 4: Cerebellar abscess vs temporal lobe abscess.
Cerebellar abscess also occurs as a complication of CSOM but arises from the posterior fossa (mastoid spread through the posterior bony plate). The CT location distinguishes these two. The ring-enhancing lesion in the temporal region with ear discharge points to temporal lobe abscess.

Conclusion: Temporal lobe abscess is the correct diagnosis.