In this case report, we describe a 55-year-old male diagnosed with ameloblastic carcinoma. The tumor arose from an intraosseous cystic ameloblastoma with prominent squamous differentiation and frank invasion of the gingiva. It is challenging to diagnose ameloblastic carcinoma based only on superficial biopsy specimen, due to prominent squamous differentiation and overlying involvement of the squamous epithelium. Radiographic images and immunohistochemical studies may be helpful for accurate diagnosis.
