Case 342

History A 70-year-old woman presented with progressively worsening midback pain over 2 months, radiating in a wraparound distribution to the lower ribs. Initially, the pain was confined to the night but eventually began to persist during the day, worsening with sitting and lying down. The pain was severe and unresponsive to paracetamol and nonsteroidal anti-inflammatory drugs. She reported no bowel or bladder issues and no weakness, numbness, or history of trauma. There was no radiculopathy in either lower extremity. She had no fever, weight loss, or history of using blood thinners. She was a former smoker with a prior transbronchial biopsy for a pulmonary nodule that was negative for malignancy or infection. She had a sister diagnosed with ovarian cancer. Physical examination demonstrated normal vital signs; preserved orientation to person, place, and time; and intact short-term and long-term memory. She had normal gait and coordination. Muscle strength was rated five of five for all four extremities, with intact sensation. Deep tendon reflexes were rated two or higher throughout. No clonus was present, and Hoffmann sign was negative. A lumbar puncture was performed at the bedside