Noriko Matsuzawa¹, Hideki Mori², Yoshihiro Kimura³, Mitsuhiro Aoki^4,

Ameloblastoma (AM) is a benign but locally infiltrative epithelial odontogenic neoplasm. An 86-year-old woman presented with swelling on the left palate gum. CT images as well as panoramic X-ray photograph displayed a multiocular radiolucent lesion extending from the alveolar process to the plate. Pathological diagnosis of the resected tumor tissue was AM arisen from the anterior maxillary bone. AM can present with a follicular, plexiform, acanthomatous, basal cell, granular or desmoplastic subtype. Present case was diagnosed as a mixed pattern of acanthomatous subtype and basal cell subtype. In this study, tumor cells of the basal cell type had a clear continuity to the islands of acanthomatous subtype suggesting that the cells of basal type could differentiate to those of acanthomatous islands. To the best of our knowledge, presence of the unique combination of acanthomatous subtype and basal cell subtype, and the mutual correlation with two subtypes of AM have not yet been described.

Ameloblastoma, Maxillary, Acanthomatous, Basal Cell, Mixed pattern