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Mycobacterium riyadhense Infection Presenting as a Central Nervous System Mass: A Case Report.
Ibrahim Bahabri1, Rahmah S Alzahrani1,2, Nouf Althabit1
1Department of Medicine, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs, Riyadh, Saudi Arabia, ngha.med.sa.
Case Reports in Infectious Diseases
|May 29, 2026
Summary
Mycobacterium riyadhense, a nontuberculous mycobacterium, can cause central nervous system masses. This case highlights its unusual presentation and initial misdiagnosis before definitive identification.
Area of Science:
- Infectious Diseases
- Neurology
- Microbiology
Background:
- Mycobacterium riyadhense is an emerging cause of mycobacterial infections.
- Nontuberculous mycobacteria (NTM) infections are increasingly reported globally.
- Nontuberculous mycobacterial infections can manifest as pulmonary or extrapulmonary disease.
Purpose of the Study:
- To report a rare case of Mycobacterium riyadhense presenting as a central nervous system mass.
- To discuss the diagnostic challenges and initial misdiagnosis of this unusual presentation.
- To highlight the importance of considering NTM in neurological mass lesions.
Main Methods:
- Case report detailing a patient with a central nervous system mass.
- Review of clinical presentation, diagnostic workup, and treatment response.
- Microbiological identification of Mycobacterium riyadhense.
Main Results:
- The patient presented with a central nervous system mass initially diagnosed as neurosarcoidosis.
- Initial treatment with steroids and rituximab showed partial improvement.
- Definitive diagnosis was established as Mycobacterium riyadhense infection.
Conclusions:
- Mycobacterium riyadhense can present atypically as a central nervous system mass.
- Neurosarcoidosis can be a differential diagnosis in such cases, leading to potential misdiagnosis.
- Early and accurate microbiological diagnosis is crucial for appropriate treatment of Mycobacterium riyadhense CNS infections.
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