An unusual complication in a 9-year-old patient with hereditary multiple osteochondromatosis.

This case report describes the presentation of a 9-year-old boy with a history of hereditary multiple osteochondromatosis who presented to the outpatient setting with progressive difficulty in ambulation. Magnetic resonance imaging of the spine revealed a thoracic spinal tumor, which was surgically removed. After surgery, the boy's ambulation and spasticity/contractures improved. This case is unique because this complication of hereditary multiple osteochondromatosis was identified at an age and in a region that are not typical. From a clinical standpoint, early identification of this complication is important because surgical treatment typically leads to good outcomes.