Introduction to a Rare Pathogen

Neurosurgeons recently documented a landmark clinical event involving a Lawsonella clevelandensis brain abscess. This microorganism is a fastidious, anaerobic, and partially acid-fast bacterium. Previously, clinicians associated it with soft tissue and visceral infections. However, this specific report marks its first identified appearance within the cranial cavity. The case highlights how advanced molecular tools solve diagnostic puzzles when traditional cultures fail.

Case Presentation and Clinical Findings

A 74-year-old woman with a history of recurrent facial squamous cell carcinoma presented with acute lower extremity shaking. Subsequent imaging revealed a large right frontal mass. This lesion extended through the calvarium and orbit, showing classic ring-enhancement. Because the patient was medically complex, the surgical team chose a bedside stereotactic biopsy. This minimally invasive strategy allowed for immediate aspiration and sample collection for analysis. Consequently, the team sent the fluid for metagenomic next-generation sequencing (mNGS) alongside routine cultures.

Managing the Lawsonella clevelandensis Brain Abscess

Traditional cultures initially provided no growth, but mNGS successfully identified L. clevelandensis. Based on these findings, physicians narrowed the antibiotic regimen to ceftriaxone and metronidazole. Furthermore, the patient required repeat drainage due to radiographic progression. She eventually underwent a multidisciplinary skull base resection. This intervention stabilized her condition significantly. Identifying this pathogen is crucial because its morphology often mimics Nocardia or Mycobacterium species, potentially leading to incorrect treatments.

Diagnostic Value of Molecular Sequencing

This case underscores the utility of molecular sequencing in culture-negative intracranial infections. Routine microbiology often misses fastidious anaerobes like Lawsonella. Therefore, mNGS serves as a vital adjunct in modern neurosurgery. Additionally, bedside stereotactic aspiration proved to be a safe and effective technique for high-risk patients. Clinicians should consider these advanced diagnostics when facing atypical abscesses associated with malignant invasion.

Frequently Asked Questions

What is Lawsonella clevelandensis?

It is a recently described anaerobic, Gram-positive rod that is partially acid-fast. It is a commensal of human skin but can cause deep-seated abscesses in immunocompromised or surgically complex patients.

Why is mNGS used for brain abscesses?

Metagenomic next-generation sequencing identifies microbial DNA directly from samples. This is particularly useful for fastidious organisms that do not grow well in standard laboratory cultures, ensuring targeted antibiotic therapy.

Is bedside stereotactic biopsy safe?

Yes, it is a minimally invasive procedure often used for medically fragile patients. It allows for diagnostic aspiration and therapeutic decompression without the need for a full craniotomy in the initial stages.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Hennen J et al. First reported case of Lawsonella clevelandensis brain abscess in the setting of invasive cutaneous squamous cell carcinoma identified via bedside stereotactic aspiration: illustrative case. J Neurosurg Case Lessons. 2026 Apr 06. doi: undefined. PMID: 41941835.

Goldenberger D et al. Emerging anaerobic and partially acid-fast Lawsonella clevelandensis: extended characterization by antimicrobial susceptibility testing and whole genome sequencing. Clin Microbiol Infect. 2019 Nov;25(11):1447-1448. doi: 10.1016/j.cmi.2019.07.008.