Tehran University Medical Journal

Background: Osteoblastoma is one of the rarest primary benign bone tumors which accounts for 1% of all bone neoplasms and 3.5% of benign bone tumors, with the potential for local invasion and recurrence. Osteoblastoma is not homogeneous. Differences in histological details have led to the division of these lesions into subtypes. The histologic features in most cases are distinctive, there are various changes that make the diagnosis challenging. Although involvement of this disease is more in the spines or small long bones, but it has been reported involvement of jaws in this disease. Correct diagnosis is very important because it may be misdiagnosed osteosarcoma  with hypercellular cases.

Case presentation: In this case report, it is described patient a 7-year-old girl with a lesion in the posterior maxilla and bone resorption in May 2016, Sari, Mazandaran province, Iran. Differential diagnosis of the radiological and clinical findings suggested an osteosarcoma. In terms of pathology, osteoblastoma was included a well-vascularized connective stroma tissue with plenty of veins which osteoid and primitive woven bone can be seen actively. In microscopy diagnosis, samples were shown cortical bone with a natural appearance, prominent osteoblasts and surrounding granulation tissue containing blood vessels that confirmed maxilla osteoblastoma. The lesion was examined by histopathology method for final recognition and the results revealed osteoblastoma.