Which of the following is not true about osteoid osteoma

Answer-C. Lesion appears ill defined on x-ray with permeative marginsOsteoid osteoma is the most common true benign tumor of the boneThe tumor occurs between 10-30 years of age and is more common in males.The diaphysis of long bones is involved, most common bone involved is the tibia followed by femurOn X-ray, there is a small radiolucent area (nidus) surrounded by dense sclerosis.X-ray, in some cases, show local sclerotic thickening of the shaft that may obscure the small central nidus within the area of rarefaction.