Desmoplastic Ameloblastoma: A case report of rare pulmonary metastasis.

Pulmonary metastasis of ameloblastoma is a rare associated with the histopathologically plexiform types of ameloblastoma. In this report, we present an exceptionally rare case of pulmonary metastatic ameloblastoma without local recurrence, emerging 12 years post-initial resection. A female patient, initially diagnosed with mandibular desmoplastic ameloblastoma, revealed masses in both lung fields of the lung on chest radiography, while chest computed tomography revealed more than 10 nodules in both lungs. Histopathological analysis of a lung biopsy specimen revealed a nest-like structure of tumor cells surrounded by highly columnar cells, exhibiting a palisade-like arrangement, and squamous metaplasia. Subsequently, the diagnosis of pulmonary metastatic ameloblastoma was confirmed through immunohistochemical examination. Despite clinical trial treatment with molecular targeted therapy for three years, the lung disease remained clinically stable. This case highlights the need for oral surgeons to recognize that pulmonary metastasis of desmoplastic ameloblastoma can manifest as a late recurrence, extending beyond a decade after initial curative surgery.