Report of a rare case of multiple hereditary exostosis with vertebral and spinal cord compression and chondrosarcomatous differentiation

Abstract

Exostosis is a benign cartilaginous lesion. Solitary lesions are called osteochondroma. In the case of multiple exostoses, which is called osteochondromatosis, a genetic defect is present and the mode of inheritance is autosomal dominant. Thoracic region is the most commonly involved locations in the spine. In extremely rare instances they may devolve into chondrosarcoma. Even with this malignant differentiation, spinal cord compression is a rare complication. We report a family with multiple exostoses and chondrosarcoma differentiation in one of the patients. The proband, a 31-year-old man, presented with progressive back pain and spastic paraparesis and local tenderness on thoracic spine. His father and his daughter had multiple exostoses, too. A large lobulated dumbbell-shaped heterogeneous mass was noted at T7-T8 level with a cartilaginous cap causing canal stenosis, spinal cord and lung compression. Radiologic findings, pathology and surgical technique are also discussed.