Intraspinal actinomycosis: a rare case report and literature review

To investigate the main clinical characteristics of intraspinal actinomycosis and help early diagnosis and treatment of this rare disease, we reported a case which was initially misdiagnosed as spinal cord tumor based on magnetic resonance imaging (MRI) findings. The diagnosis of intraspinal actinomycosis was eventually confirmed by histopathology. We further studied the relevant literatures to comprehensively understand this uncommon disease. We searched through PubMed database using the keywords “actinomycosis” and “spinal cord” before Mar 20, 2016. We retrieved 26 articles describing 27 actinomycosis case reports with spinal cord involvement. Then, we analyzed their clinical manifestation, diagnosis, treatment and prognosis. Together with our case, analysis of the 28 cases revealed that 71.4% (20/28) patients were diagnosed by histopathology and 32.1% (9/28) by culture. The difference between intraspinal and common actinomycosis was that most patients in our study series were immunocompetent [89.3% (25/28)]. Penicillin based treatment regimen accounted for 88.5% (23/26) intraspinal actinomycosis cases and the mean duration of antibiotic therapy was 6 months. Although rare, actinomycosis is an important pathogen for intraspinal inflammatory granulomas. Specimen biopsy or culture is essential for a correct diagnosis with biopsy highly recommended. Early initiative and long-term antibacterial therapy is crucial for improving prognosis. Direct decompressive surgical resection of spinal cord lesion is helpful for relief of symptoms.