Which benign bone tumor characteristically arises as a bony outgrowth from the metaphysis of long bones covered by a cap of hyaline cartilage, and is associated with mutations in the EXT1 or EXT2 genes when present in multiple form?

• A Osteoid osteoma
• B Osteochondroma ✓
• C Enchondroma
• D Giant cell tumor

Explanation

Osteochondroma, also called exostosis, is the most common benign bone tumor. It forms a cartilage-capped bony projection at the metaphysis pointing away from the joint. Multiple lesions define hereditary multiple exostoses due to EXT1 or EXT2 germline mutations. Enchondroma lies within the medullary cavity and lacks a cartilaginous cap over cortical bone.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.