Intracortical osteosarcoma; two-year delay in diagnosis.

Intracortical osteosarcoma is the rarest type of osteosarcoma. In most instances the tumor arises in the cortex of the femur, less commonly, in the tibia. We describe an 11-year-old patient with intracortical osteosarcoma of the tibia in whom the tumor was present for 2 years and became painful 3 months prior to presentation.