SHM Converge Scientific Abstract ePoster Gallery-Case of Multiple Ring Enhancing Abscesses in an Immunocompetent Patient

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This case describes a rare presentation of multiple ring-enhancing brain abscesses in an immunocompetent 56-year-old man without intravenous drug use. He presented with progressive hallucinations and altered mental status, leukocytosis, elevated inflammatory markers, and MRI showing multiple supra- and infratentorial ring-enhancing lesions with early ventriculitis. Extensive infectious and systemic workup was negative. Burr hole aspiration identified <strong>Streptococcus intermedius</strong>, a member of the Streptococcus anginosus group known for abscess formation.

The report emphasizes that the differential diagnosis of multiple ring-enhancing brain lesions depends strongly on immune status. In immunocompetent patients, key considerations include abscess, malignancy/metastases, and demyelinating disease. Radiographic clues are important: abscesses often show a thin enhancing rim, a relatively homogeneous center, and diffusion restriction, whereas tumors may have different T2 and metabolic features. When imaging is equivocal, brain biopsy may be definitive but carries risk; advanced imaging such as MR spectroscopy or PET can help.

The source of <strong>S. intermedius</strong> infection was thought to be hematogenous spread, possibly related to prior thoracic trauma and chest tube placement, with poor dentition as another possible contributor. The patient was treated with ceftriaxone and metronidazole, plus seizure prophylaxis and steroids, and improved enough for discharge to rehabilitation.

One month later, after elective tooth extraction, he returned with headache and encephalopathy. Repeat MRI showed that the abscesses were smaller but ventriculitis had developed, consistent with rupture of the abscesses into the ventricles. Antibiotics were continued, and his ventriculitis-related headaches improved with multimodal pain management.

The main teaching points are that multiple ring-enhancing abscesses in immunocompetent patients are unusual and should prompt a search for local or hematogenous infection sources, and that recurrent neurologic symptoms in known brain abscesses warrant repeat imaging to assess for complications such as ventriculitis.

Asset Subtitle

Kaylin Cho

Meta Tag

Author List Adeoluwa Ayoola, Fiona Ng, Kaylin Cho, Nathan Ziman

Category Clinical Vignettes

Concept Multiple Ring-Enhancing Brain Lesions

Concept Cerebral Abscess

Concept Differential Diagnosis

Concept Diagnostic Workup

Concept Metastatic Infection

Distinguished Non-Finalist

Presenter Organization University of California, San Francisco, Department of Anesthesiology

Presenting Author Kaylin Cho

Track Adult

Keywords

brain abscess

ring-enhancing lesions

immunocompetent

Streptococcus intermedius

ventriculitis

MRI

hallucinations

altered mental status

hematogenous spread

differential diagnosis

Multiple Ring-Enhancing Brain Lesions

Cerebral Abscess

Differential Diagnosis

Diagnostic Workup

Metastatic Infection