The characteristic histological findings of AD including islands and cords of basaloid epithelial cells

The characteristic histological findings of AD including islands and cords of basaloid epithelial cells in a fibrous stroma with nuclear atypia and mitotic figures.

A lateral radiograph of a tibia with multifocal lytic lesions and areas of intervening sclerosis, which can give a “soap bubble” appearance.

Differentiating between adamantinoma (AD) and osteofibrous dysplasia (OFD) can be difficult, as the two lesions share many similar characteristics. AD is a rare, low-grade malignant primary bone tumor that occurs most often in the tibia and/or fibula of adolescent persons and young adults; however, it has been reported in other long bones, as well. Histologically, AD is composed of islands of epithelial cells in a spindle-cell stroma and nuclear atypia with mitotic figures may be present as well. OFD is a rare, benign, fibro-osseous lesion that typically is seen within the cortex of the tibia in children. Microscopically, OFD is characterized by a loose, often storiform fibrous background containing spicules of woven bony trabeculae that are lined by a layer of osteoblasts. Treatment of OFD in children usually consists of observation.