Most common benign tumor of bone:

Ans. a (Osteochondroma).OSTEOCHONDROMA OR EXOSTOSIS OR CARTILAGE CAP TUMOR# It is the most common skeletal neoplasm. It is most common benign bone tumor.# It accounts for 20-50% of benign bone tumors and 10-15% of all bone tumors.# It occurs most frequently in the first two decades of life with a ratio of M:F of 1.5 to 1.# Found most often in long bones, especially the distal femur and proximal tibia, with 40% around the knee.# Hereditary multiple osteochondromatosis (diaphyseal achalasis) is an autosomal dominant condition. The risk of malignant transformation to chondrosarcoma in hereditary multiple osteochondromatosis is unknown, but may be 25-30% compared to approximately 1% for a solitary osteochondromas.# In general, a sessile lesion is more likely to degenerate into sarcoma than an exostosis.# Plain films are normally enough to diagnose osteochondromas. Sessile lesions cover a wide area and as a result cause metaphyseal widening or a "trumpet shaped deformity" on X-ray.# Relationship of the lesion to other structures and the thickness of the cartilage cap best delineated with MRI.# Over 2 cm of cartilage or renewed growth of a dormant lesion indicate malignant transformation.# If the lesion is causing pain or neurologic symptoms due to compression it should be excised at the base.# As long as the entire cartilage cap is removed there should be no recurrence.