Case 298.

History A 37-year-old man from the United States presented with a 1-year history of neck pain and stiffness that had been unsuccessfully treated with manipulative therapy by a chiropractor at another institution. Past medical history was remarkable only for marijuana and air duster abuse. He denied use of any prescription medications. Physical examination was notable for markedly reduced range of motion of the cervical spine. Laboratory work-up revealed an elevated alkaline phosphatase level (302 U/L [5.0 μkat/L]; normal range, 40-100 U/L [0.7-1.67 μkat/L]), but all other laboratory findings, including complete blood count, renal function, liver function, vitamin A level, serum protein electrophoresis, and hepatitis C antibodies were within normal limits. Cervical spine radiography was performed (Fig 1), followed by MRI (Fig 2). Subsequently, a full skeletal survey was ordered. Included are representative radiographs of the pelvis (Fig 3), left forearm (Fig 4), and distal right leg with ankle (Fig 5).