Osteofibrous dysplasia-like adamantinomas occur in children and adolescents and behave relatively benign, whereas classic adamantinomas predominate in adults and have a more aggressive clinical course.
Adamantinoma is most frequently seen in tibia and has been reported to involve the adjacent fibula occasionaly.
Variants
osteofibrous dysplasia-like form with scattered epithelial elements
Types
classic form with abundant epithelium
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)
Nota bene: 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.