Variants

 osteofibrous dysplasia-like form with scattered epithelial elements. Some osteofibrous dysplasia-like tumors have progressed to classic adamantinomas, it is hypothesized that the former is a potential precursor of the latter, showing mesenchymal-to-epithelial transformation.
 classic form with abundant epithelium are distinguished
 dedifferentiated adamantinoma with revertant mesenchymal phenotype

• sarcomatoid transformation of the epithelial component
• Histologically, the tumors showed loss of the original characteristic epithelial differentiation with transition to fields of highly pleomorphic cells without epithelial features, high mitotic count, and deposition of osteoid and chondroid matrix. These dedifferentiated areas showed pankeratin positivity as well, although there were some changes in keratin subclass profile compared with other classic adamantinomas. (#14657712#)