A case of fatigue fracture in the left tibia was presented. He was 13 years old boy, complaning of pain and swelling in the left leg.
The rotatotomographic picture showed the formation of periosteal and endosteal callus.
The biopsy was performed for the purpose of the differential diagnosis from osteosarcoma. The histological findings revealed marked enlargement of Haversian canals and numerous resorption cavities, that is, cancellization in the cortical bone. In addition, the formation of cartilaginous tissue was slightly recognized the cleft of fracture. In the periosteal callus, lamina could not be recognized, and the formation of fibrous, immature bone trabeculae were found.