Intraosseous Ameloblastoma with a Prominent Extraosseous Component: Pitfalls in Diagnosis

Abstract

For many years, gingival tumors of what appear to be peripherally located intraosseous ameloblastoma (IA) arising from the alveolar bone surface have often been confused with peripheral ameloblastoma (PA) causing resorption of the underlying bone. We analyzed a series of five cases of ameloblastoma that demonstrated a combined PA and IA architecture. The tumor commonly involved the anterior-premolar area, mostly in the maxilla and mainly in middle-aged men. The clinical presentation was an exophytic gingival mass inferior to which was a small bone defect. The predominant extraosseous component showed a papillary gross surface, reflecting the histologic proof of fusion between the submucosal tumor and the surface epithelium. In addition to the PA-like growth pattern, common to all was the presence of neoplastic destruction of the alveolar process, corresponding to an associated radiolucent lesion. This restrained component was acceptable as IA. In two cases, recurrence was observed deep in the alveolar bone with no involvement of the gingiva. These tumors appear to be IA that arose from the marginal alveolar bone and grew preferentially in the gingiva, forming a PA-like appearance. From diagnostic, therapeutic and prognostic points of view, this type of IA should not be confused with PA.

CD1a‐positive Langerhans cells and their relationship with E‐cadherin in ameloblastomas and keratocystic odontogenic tumors

“…Ameloblastomas (AMs) and keratocystic odontogenic tumors (KOTs) are benign tumors derived from the odontogenic epithelium that are characterized by a fibrous and mature stroma and the lack of involvement of odontogenic ectomesenchyme . These tumors show a locally invasive growth pattern and cause extensive bone destruction .…”

Peripheral ameloblastoma with neoplastic osseous invasion versus peripheral intraosseous ameloblastoma: A challenging diagnosis

“…The presence of osseous invasion in lesions, which otherwise shows the features of peripheral ameloblastoma histopathologically, is said to be diagnostic of peripheral intraosseous ameloblastoma, and the presence or absence of ameloblastomatous islands within the adjacent bone had been used as a criterion to differentiate between these two lesions. [8]…”

Maxillary ameloblastoma—Rare tumor in a child

“…Ide et al suggested prompt consideration of intraosseous variety in cases of identifiable radiological or clinical bony erosion. Also when larger than 2 cm, the diagnosis should be backed more with the more troubling multicystic type [8].…”