Aggressive thoracic actinomycosis complicated by vertebral osteomyelitis and epidural abscess leading to spinal cord compression

Report of a successfully diagnosed and treated case of spinal cord compression due to epidural actinomycosis. To illustrate that proper use of imaging strategy can greatly facilitate diagnosis and management of this rare condition. Spinal actinomycosis causing epidural abscess and significant spinal cord compression is an uncommon condition. Although diagnosis is difficult, favorable results are widely reported when specific therapy is instituted. A 32-year-old Chinese man had extensive dorsal thoracic soft tissue swelling and lower limb weakness. Collapse of the T5 vertebral body was found on plain radiographs with mediastinal infiltrates on chest radiograph. It took magnetic resonance imaging (MRI) to fully delineate the epidural abscess and dorsal muscular abscesses, which were not depicted by computed tomographic (CT) scan. Diagnosis was made by examination of CT-guided aspirate and tissue recovered during surgery by a microbiologist. The patient received high-dose intravenous penicillin and prompt spinal decompression once diagnosis of actinomycosis was confirmed. The dorsal muscular abscesses and upper thoracic epidural abscess resolved rapidly after intravenous antibiotics and surgical drainage. This was well documented by follow-up MRI and the full recovery of motor power and lower limb sensation in the patient. High clinical suspicion and proper use of imaging data led to timely diagnosis of this rare case of mediastinal, epidural, and intramuscular thoracic actinomycosis. Specific antibiotic therapy and timely, well-targeted surgical intervention greatly improve the outcome of this condition.