Case Report: Metastatic Ameloblastic Carcinoma with Pulmonary, Rib, and Pericardial Metastases and Subsequent Management of Rib Pain

Ameloblastoma, a benign yet locally aggressive odontogenic tumor, can rarely undergo malignant transformation to ameloblastic carcinoma (MAC), a highly aggressive malignancy with a propensity for distant metastasis. While lungs are common metastatic sites, involvement of the pericardium is exceedingly rare. This case report details the challenging clinical course of a 71-year-old male veteran who initially presented with maxillary ameloblastoma in 2019. Despite initial treatment, he experienced recurrence in 2024, which histologically demonstrated transformation to ameloblastic carcinoma with extensive invasion. Subsequently, he developed symptomatic metastatic disease, including a biopsy-proven lesion in the left fourth rib requiring palliative radiation, discrete pulmonary nodules, and a 1.9 cm pericardial metastasis that also received external beam radiation. The patient's complex journey highlights diagnostic delays, the aggressive nature of MAC, the critical need for a multidisciplinary approach, and systemic barriers in accessing timely specialized care. This case underscores the importance of vigilant long-term surveillance for ameloblastoma and aggressive management strategies for its malignant transformation, especially when rare metastatic patterns emerge.