Explanation:
Hereditary Multiple Exostoses (HME) is an autosomal dominant condition characterized by multiple osteochondromas. The risk of malignant transformation into a secondary chondrosarcoma in HME is approximately 1% to 5%, which is significantly higher than the almost negligible risk in a solitary osteochondroma or a solitary enchondroma. Lesions of the pelvis and proximal femur are at the highest risk. Reference: Orthopaedic Pathology, 6th Edition.