Ameloblastic carcinoma (AC) is a rare, primary epithelial odontogenic malignant neoplasm. It is the malignant counterpart of ameloblastoma. It comprises 1% of all cysts and tumours occurring in the jaws, arising from tissues associated with odontogenic epithelium. The objective of the present study was to describe a clinical case of a 63-year-old male with an enlargement in the mandible on the left side. Panoramic radiography revealed a radiolucent area with poorly defined borders, and an incisional biopsy was performed for the histopathological study using immunomarkers such as SOX2 and Ki-67. Ki-67 is considered a marker of cell proliferation, and SOX2 reportedly participates in the development of the ameloblastic epithelium lineage and is associated with a more aggressive clinical course. A final histopathological diagnosis of AC was given. Unfortunately, the patient died one week before surgical resection (the surgical treatment of choice for AC).