SHM Converge Scientific Abstract ePoster Gallery-Streptococcus Intermedius Brain Abscess Mimicking a Necrotic Tumor

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This case describes a 55-year-old woman with stage IV intranasal mucosal melanoma on nivolumab who developed a worsening right temporal headache, cough, and sore throat. She also had right facial numbness and weakness, mild leukocytosis, and no fever. Because of her cancer history, MRI findings of a 2.0 x 1.7 cm ring-enhancing right temporal lobe lesion with restricted diffusion and hemosiderin were initially interpreted as a hemorrhagic, necrotic metastasis. She was started on dexamethasone and levetiracetam.<br /><br />On review, the lesion was recognized as a cerebral abscess. Broad-spectrum antibiotics were begun, and on hospital day 5 she underwent craniotomy with aspiration of the abscess. Culture grew Streptococcus intermedius. Antibiotic therapy was narrowed to IV penicillin G for six weeks, followed by oral penicillin V. Follow-up imaging at 1 month showed complete resolution, and 7-month imaging confirmed no recurrence.<br /><br />Her headache improved significantly, though she later developed focal seizures with secondary generalization and required antiepileptic therapy. She remained seizure-free at follow-up.<br /><br />The report emphasizes that brain abscesses are uncommon but can mimic tumors such as metastases or cystic gliomas, especially in patients with cancer or immunosuppression. Fever and altered mental status may be absent, making diagnosis challenging. Diffusion-weighted MRI is especially helpful in distinguishing abscess from other intracranial masses. Early neurosurgical aspiration for diagnosis and drainage, combined with 6–8 weeks of targeted antibiotics, is essential because treatment delays can markedly increase mortality.

Asset Subtitle

Amy Jayson

Meta Tag

Author List Amy Jayson, Hardik Thakkar, Lesly Benodin, Neha Verma, Phillip Jules

Category Clinical Vignettes

Concept Cerebral Abscess

Concept Ring-Enhancing Lesion

Concept Magnetic Resonance Imaging

Concept Restricted Diffusion

Concept Neurosurgical Aspiration

Distinguished Non-Finalist

Presenter Organization Moffitt Cancer Center

Presenting Author Amy Jayson

Track Adult

Keywords

brain abscess

mucosal melanoma

nivolumab

ring-enhancing lesion

diffusion-weighted MRI

Streptococcus intermedius

craniotomy aspiration

intracranial metastasis

penicillin G

focal seizures

Cerebral Abscess

Ring-Enhancing Lesion

Magnetic Resonance Imaging

Restricted Diffusion

Neurosurgical Aspiration