Ameloblastic fibro-odontoma: a diagnostic challenge

Abstract

An 11-year-old girl presented to our department to have a second opinion regarding a lesion involving her left mandible. She had previously undergone several radiographic exams including panoramic, helical, and cone-beam computed tomography. Radiographic examinations revealed a well-defined radiolucent region, which contained an irregular radiopaque mass of 3 cm in diameter, localized to the left angle of the mandible. Our presumptive diagnosis was complex odontoma. Excisional biopsy was performed, and microscopic features showed strands and islands of odontogenic epithelium showing peripheral palisading and loosely arranged central cells, identical to stellate reticulum, embedded in a myxoid cell-rich stroma resembling the dental papilla. Dentin and enamel were also presented. The diagnosis was ameloblastic fibro-odontoma, which is a rare mixed odontogenic tumor, derived from epithelial and ectomesenchymal elements that form the dental tissues.

Figure 1

Initial panoramic radiography showing well-defined radiolucent region, which contained an irregular radiopaque mass measuring 3 cm in diameter. This lesion occupied a zone from the lower left second molar area to the left ramus.

Figure 2

Helical computed tomography images showing an expansile, well-circumscribed lesion containing a calcified mass compatible with odontogenic tissue ((a) axial cuts; (b) coronal cuts).

Figure 3

Cone-beam tomography (panoramic reconstruction) showing a well-circumscribed calcified mass in intimate contact with the alveolar inferior nerve.

Figure 4

(H.E.) Strands (red arrow) and islands (black arrows) of odontogenic epithelium showing peripheral palisading and loosely arranged central cells, identical to stellate reticulum embedded in myxoid cell-rich stroma resembling the dental papilla (*).

Figure 5

(H.E.): Dentin (d) and enamel matrix (em).