Metastasizing ameloblastoma

ABSTRACT

@#A 27-year-old man presented with an 8 cm diameter left maxillary mass and an enlarged cervical lymph node at levels II to III. There was a reported history of a previous unspecified operation on the maxillary mass which had yielded a diagnosis of ameloblastoma. Total maxillectomy with modified radical neck dissection was subsequently performed. Microscopic examination of the maxillary mass shows epithelial islands and cords in a fibro-collagenous stroma. (Figure 1) The islands and cords are lined in the periphery by palisaded columnar cells with regular ovoid nuclei exhibiting reverse polarization. The nuclei are uniform with dispersed chromatin and no significant atypia. Towards the center of these islands are loosely arranged spindly to stellate cells (“stellate reticulum”). (Figure 2) Microscopic examination of the largest submitted lymph node shows an epithelial neoplasm with identical histologic features as the maxillary mass and a residual rim of lymphoid tissue at the periphery enclosed by the nodal capsule. (Figure 3) Similarly, there is neither atypia nor pleomorphism and only a few typical mitotic figures are seen in the nodal tumor. (Figure 4) These features support the diagnosis of a metastasizing ameloblastoma (MA).