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Updated: Jun 9, 2026
Modeling Brain Metastases Through Intracranial Injection and Magnetic Resonance Imaging
Published on: June 7, 2020
Brain metastasis mimicking brain abscess: illustrative case and systematic review
Anoop S Chinthala1, Barnabas Obeng-Gyasi2, Kenneth L Virgin1
1Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
Background:
Diffusion-weighted imaging (DWI) is a valuable tool in distinguishing brain abscesses from neoplastic lesions, with restricted diffusion often interpreted as indicative of infection. However, some metastatic brain lesions can mimic abscesses both radiologically and clinically, presenting a diagnostic challenge.
Observations:
A 58-year-old woman presented with confusion and was found to have multiple ring-enhancing brain lesions with uniform restricted diffusion on DWI. Initial imaging raised concern for pyogenic abscesses, and empiric antibiotics were initiated. However, systemic imaging revealed a left upper lobe lung mass, and stereotactic biopsy confirmed metastatic adenocarcinoma. The authors performed a systematic review and identified 28 studies describing metastatic lesions with restricted diffusion, most involving solitary lesions with partial restriction. Only a few described multiple lesions with partial restricted diffusion. Lung adenocarcinoma was the most common primary source.
Lessons:
This case illustrates that metastatic disease can mimic abscesses on DWI, particularly when lesions are ring enhancing and diffusion restricting. In the absence of clear infectious signs, a broader differential should be considered. Clinical context, systemic imaging, and early biopsy may help clarify the diagnosis and guide appropriate management. https://thejns.org/doi/10.3171/CASE25528.
Insights
Metastatic brain lesions can mimic abscesses on diffusion-weighted imaging (DWI), especially with ring enhancement and restricted diffusion. Consider metastatic disease in the differential diagnosis when clear infection signs are absent.
Area of Science:
- Neurology
- Radiology
- Oncology
Background:
- Diffusion-weighted imaging (DWI) aids in differentiating brain abscesses from neoplastic lesions.
- Restricted diffusion on DWI typically suggests infection, but some metastatic lesions can mimic abscesses radiologically and clinically.
Purpose of the Study:
- To highlight the potential for metastatic brain lesions to mimic abscesses on DWI.
- To emphasize the importance of considering metastatic disease in the differential diagnosis of ring-enhancing, diffusion-restricted brain lesions.
Main Methods:
- Case presentation of a patient with multiple ring-enhancing brain lesions and restricted diffusion.
- Systematic review of 28 studies on metastatic lesions with restricted diffusion.
- Analysis of lesion characteristics, number, and primary tumor source.
Main Results:
- The case demonstrated multiple ring-enhancing lesions with uniform restricted diffusion, initially suspected as abscesses.
- The systematic review found most metastatic lesions with restricted diffusion were solitary and partially restricted.
- Lung adenocarcinoma was the most frequent primary source among reviewed studies.
Conclusions:
- Metastatic disease can present as ring-enhancing, diffusion-restricted lesions mimicking brain abscesses on DWI.
- A broad differential diagnosis is crucial when infectious signs are not apparent.
- Clinical context, systemic evaluation, and biopsy are key for accurate diagnosis and management.
