Osteoblastoma in the retromolar region: a case report Osteoblastoma em região retromolar: relato de caso

Osteoblastoma is a rare benign tumor that accounts for less than 1% of all bone tumors. About 10% of osteoblastomas are found in the skull bones and almost half of these cases involve the mandible, especially the posterior segments. This report describes the case of a 27-year-old female patient with a unilocular radiopaque expansive lesion in the left mandible, which had well-delimited margins and caused mild bone expansion. Microscopic analysis revealed the presence of mineralized material in the form of irregularly arranged vital trabeculae at different stages of mineralization. Osteocytes were trapped inside these trabeculae, which contained osteoclast-like multinucleated cells and voluminous pavement cells with hyperchromatic nuclei, sometimes interpreted as osteoblasts. Many bone-producing lesions have clinical, radiologic and histopathologic features that resemble osteoblastoma. The understanding and correlation of these findings are extremely important since they contribute to the correct diagnosis and appropriate treatment of this rare entity, improving its prognosis.