A 19 year young patient with sclerotic lesion at diaphysis. What is the MOST likely diagnosis?

This patient most likely has osteoid osteoma which is a benign bone forming tumor characterized by small size, limited growth potential and dispropoionate pain. It usually affects children and adolescents. It commonly involves diaphysis of long bones, paicularly in the proximal humerus. Patients usually presents with pain with nocturnal exacerbations. It is usually relieved with NSAIDS. On X ray it appears as dense coical sclerosis surrounding a radiolucent nidus. Ewing's sarcoma affects long bones such as femur, tibia or humerus in young and affects flat bones in young patients. In the long bones, tumor almost always affects the metaphysis or diaphysis. X ray shows onion peel appearance due to alternate layers of reactive new bone formation and the tumor tissue. Osteosarcoma is a highly malignant bone tumor, it affects metaphysis of long bones. Ref: Pathology and Genetics of Tumours of Soft Tissue and Bone edited by Christopher D. M. Fletcher, page 260. Sho Textbook of Surgery By Roy, page 387