A 50 year-old female presented to the emergency room with back pain and left leg numbness of four days duration. The patient did not identify any contributing factors but did recall being thrown to the ground during an assault several weeks earlier. No fecal or urinary incontinence, lower extremity weakness or saddle anesthesia was reported. Her past medical history was significant for a lumbar laminectomy several years prior. The patient denied tobacco, alcohol or illicit drug use.
On examination her pulse was 65 beats/minute, respiratory rate 24 breaths/minute, temperature 98.2 F, blood pressure 124/77 mmHg and oxygen saturation of 98% on room air. In general she appeared in mild discomfort. Neurological exam revealed decreased sensation to light touch over the left anterior tibia. The remainder of the physical and neurological exam was unremarkable. Initial laboratory analysis showed a leukocyte count of 11,500 (per mm3) and platelet count of 558,000 (per m3); the hemoglobin, electrolytes and renal function were all within normal limits. Erythrocyte sedimentation rate was 85 mm/Hr and the c-reactive protein was 1.5 nMol/L.
A magnetic resonance imaging study of the lumbar spine revealed enhancing paravertebral soft tissue at L4-L5 concerning for underlying infection (Figure 1). The imaging also revealed a probable epidural abscess with significant canal narrowing to 5.5 mm. A computed tomography guided biopsy revealed reactive fibrosis, neovascularization and degenerative changes with acute and chronic inflammatory cells. The patient was begun on intravenous vancomycin and cefepime for the empiric treatment of vertebral osteomyelitis and an accompanying epidural abscess. A neurosurgical consultation was obtained and deemed there was no need for surgical intervention at that time. Cultures from the biopsy were initially negative and the patient was discharged to a skilled nursing facility to complete a six week course of the aforementioned antibiotics. The day following discharge cultures revealed acid fast bacilli, and several days later a specific identification of Mycobacterium abscessus was made. The patient was referred to the county health department tuberculosis clinic but was unfortunately lost to follow up.