Cerebral abscess

Case contributed by Assoc Prof Frank Gaillard


A 4-week history of headache and dizziness and episodic disorientation.

Patient Data

Age: 35 years

A peripherally enhancing lesion in the left parietooccipital region is surrounded by extensive vasogenic edema. 


A peripherally-enhancing, multi-septated lesion within the left parietal lobe is surrounded by vasogenic edema with positive mass effect. The central non-enhancing components are heterogeneously T2 hyperintense with incomplete suppression on FLAIR, and demonstrate diffusion restriction. There is a thin rim of susceptibility. 

There is some increased cerebral blood volume at the posterolateral aspect of the lesion, however, the lesion and surrounding white matter predominately demonstrate significantly reduced cerebral blood volume.

Spectroscopy reveals an elevated lactate peak.

There is partial effacement of the left lateral ventricle occipital horn, with mild enlargement of the left lateral ventricle temporal horn, suggestive of entrapment. No ependymal enhancement or abnormal diffusion restriction within the ventricles to suggest ventriculitis. 

Conclusion: left parietal peripherally-enhancing lesion has appearances of a cerebral abscess.

Case Discussion

On further questioning, the patient had had routine dental care 2 months ago which, however, is probably true of 10 - 20% of the population at any given time.  Normal white cell count, lightly raised neutrophils (8.3) increased CRP 14.3.

The patient went on to have drainage that confirmed an abscess. 


Specimen description: brain pus

  • Gram Stain
    • Polymorphs ++
    • Gram positive cocci VC
    • Fungal elements NOT seen
  • Culture: Aggregatibacter aphrophilus +++
  • Nocardia culture: No growth
  • Acid Fast Bacilli: negative
  • TB PCR: negative
  • Fungal cultures: negative

The patient underwent routine postoperative care and improved. 

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