Epithelioid osteoblastoma in the periapical region of maxillary molars: a rare case report

Osteoblastoma is a rare benign bone-forming neoplasm which rarely affects the jaws. Due to the rarity and wide range of clinical, radiographic, and histopathological findings, the diagnosis of gnathic osteoblastoma can be challenging. The authors report here an unusual case of osteoblastoma in the periapical region of maxillary molars. An 18-year-old woman presented with pain and swelling of the right maxillary posterior region. Computed tomography scan revealed awell-circumscribed periapical radiolucency with scattered radiopaque foci above the maxillary right first and second molars. Mucosal thickening of the right maxillary sinus was observed. The presence of teeth with pulp vitality excluded the possibility of apical periodontitis, and the intact corticated floor of the sinus also implied a sinusitis of nonodontogenic origin. The radiographic findings and the location of the lesion suggested the possibility of odontogenic cyst or tumor. Permanent histology and immunohistochemical studies revealed an epithelioid osteoblastoma. This case highlights the importance of considering osteoblastoma in the differential diagnosis of periapical lesions of vital teeth, especially with a mixed radiolucent and radiopaque appearance. Definite diagnosis depends on histopathological examination.