A large multifocal aggressive osteoblastoma of mandible: an immunohistochemistry case study report

Aggressive osteoblastoma (AO) is a benign osteoblastic tumor which is rare in the head and neck region. Clinical and histo-logical features are therefore overlap with other benign and low-grade malignant tumors. The aim of this article is to report and discuss the differential diagnosis of an aggressive osteoblastoma in the mandible. A 25-year-old male patient reported with pain and asymmetry on the left side of the face since 8 months previously. Radiographic evaluation showed a mixed lesion extending from approximately the lower left premolar to the third molar region. After incisional biopsy, resection with continuity defect was carried out. Microscopic findings showed woven bone and bony trabeculae with varied degrees of mineralization along with sheets of osteoblast cells. Immunohistochemistry showed that p53 and cytokeratin (CK) were negative and ki-67 index was 7%. Postoperative follow-up for 15 months showed no evidence of recurrence.