An unusual cause of low back pain

A 52-year-old man with a past medical history significant for lumbar spinal stenosis presented to the clinic with new-onset acute low back pain. His pain began 1 week ago when he was reaching down to pick his toothbrush up off the bathroom floor; he said he felt a “pop” in his back. Since this incident his pain has been unrelenting and has affected his activities of daily living; as a result, he missed multiple days of work. His current pain is an 8 on a 0 to 10 pain intensity rating scale, and he says it worsens with movement. He took 200 mg of ibuprofen every 4 to 6 hours with minimal relief. A back specialist has been treating the patient for several months for symptoms related to spinal stenosis; however, his current pain is quite different than his usual back symptoms. He completed a week of physical therapy about a year ago related to spinal stenosis, but has had no further therapy. He admits to fatigue for 3 days, difficulty sleeping, low back swelling, muscular tenderness, stiffness, and backache. He denies weight change, fever, skin changes, headache, shortness of breath, chest pain, numbness, tingling, radiation of pain, and bladder or bowel incontinence. He denies any history of radiographic imaging for his low back pain.

He was given ketorolac, 60 mg IM injection in the office; and prescribed diclofenac 1% topical cream every 4 hours as needed; and tramadol, 50 mg every 6 hours as needed.

The patient returned 2 weeks later with diminished sensation in his right foot and an unstable gait. He was diagnosed with foot drop and was referred for MRI with gadolinium, which revealed a 1 cm × 1 cm spinal mass at the L3-L4 lumbar spinal cord vertebral region. Management involved a laminectomy with total surgical resection; pathology revealed a low-grade tumor (WHO grade I) called a myxopapillary ependymoma.

Acute lumbosacral back pain is one of the most common diagnoses encountered in primary care and EDs. Although most cases are related to musculoskeletal strain, a more insidious diagnosis may be the underlying cause of symptoms. Myxopapillary ependymoma is a type of spinal cord tumor that most commonly arises in the lumbosacral spinal cord and filum terminale. Patients with this tumor generally present with low back pain (with or without radicular features), sensory dysesthesias, and muscle weakness, especially of the iliopsoas musculature. The most frequent local effect of spinal cord malignancies is atypical nocturnal pain leading to nocturnal awakening. In this case, the patient's acute-onset low back pain ultimately was attributed to a spinal tumor.

Research analysis for genomic pathogenesis of ependymomas is ongoing. As a result, specific red-flag symptoms and target therapies associated with these types of tumors are unclear. This case is unusual as ependymomas are most commonly discovered in young adults, with an average age at diagnosis of 37 years. Additionally, the patient denied unrelenting nocturnal pain and nocturnal awakening, even though the medical literature suggests that this type of severe nighttime pain often accompanies spinal cord malignancies. This case illustrates the benefit of having a high clinical suspicion for malignancies, even in the most common, every-day complaints.