The Minimalistic Metamorphoses-Adamantinoma

Abstract

Adamantinoma is an exceptional, primary, malignant, low-grade bone, biphasic, fibro-osseous bone neoplasm of uncertain origin typically constituted of epithelial articulations embedded within a mesenchymal or osteofibrous dysplasia-like stroma. Adamantinoma commonly arises within diaphysis and metaphysis of tibia in addition to ulna, femur, fibula, humerus, radius, ribs, tarsal and metatarsal bones. Adamantinoma depicts a repetitive mutation of KMT2D (MLL2) gene along with fusion of somatic gene EPHB4-MARCH10. Expression of DLK1 gene is enhanced. Adamantinoma is subdivided into diverse categories such as classic subtype, osteofibrous dysplasia-like or differentiated adamantinoma and dedifferentiated adamantinoma. The neoplasm is comprised of epithelial cells with minimal atypia disseminated within an osteofibrous dysplasia -like stroma. Solid nests of basaloid cells with peripheral palisading, tubular structures, clusters of keratinized squamous epithelium or fascicles of spindle-shaped cells are exemplified.