Benign tumors

Osteoma -

benign; most commonly arises on surface of facial bones; associated with Gardner syndrome

Osteoid osteoma

a benign bone forming neoplasm which is usually cortically based and extra-articular, with characteristic reactive sclerosis. (Intracapsular, intramedullary and subperiosteal lesions may also occur.)

Osteoid osteomas that are intra-articular incite little or no sclerosis. Intra-medullary and subperiosteal lesions provoke variable degrees of sclerosis.

affects age 5 - 24 years

most common in the lower extremities at the diaphyses; may occur in posterior elements of the spine

usually presents with pain which is worse at night and is relieved with aspirin/ naproxen/ ibuprofen

Complications

growth disturbances such as leg lenght discrepancy or bowing of an extremity or scoliosis

maybe associated with osteoblastoma

Dx

Radiographs show a sclerotic lesion and sometimes a localized lytic defect or nidus (<1 cm in diameter) within the sclerotic bone

DDx includes Brodie's abscess or stress fracture

Histology = a nidus of immature, woven, trabecular bone and osteoblasts surrounded by dense sclerotic bone

Tx

Surgical excision

Osteochondroma

most common benign tumor of bone