Originally: a tumour of odontogenic epithelial cells (adamantoblasts) occurring in the jaws; = ameloblastoma (now rare). In later use: a tumour with a similar histological appearance occurring especially in the tibia.
The histogenesis of the adamantinoma of the tibia is unclear. These tumours are generally considered to be benign, but can be locally aggressive or capable of metastasis.
Early 20th century. From adamantine + -oma, probably after German Adamantinom.