Metastasizing Ameloblastoma With Localized Interstitial Spread in the Lung: Report of Two Cases

Ameloblastoma is a locally aggressive, epithelial odontogenic tumor involving mandibles and maxillas. Distant metastasis is a very rare condition and is designated as metastasizing (malignant) ameloblastoma despite its benign histological appearance. Up to now, only 27 well-documented cases of metastasizing ameloblastomas are reported in the literature, and lung is the most commonly involved organ. In previous reports of pulmonary metastasizing ameloblastomas, there was little description of the histopathologic finding. Here, the authors report 2 cases of pulmonary metastasizing ameloblastomas with special emphasis on their interesting, interstitial spread along alveolar septa, resulting in a unique 2-cell pattern under microscopic examination. Pulmonary metastasizing ameloblastoma may pose difficulty in diagnosis if the pathologist is not aware of patient's clinical history of ameloblastoma.