Chondroblastoma and chondromyxoid fibroma: disentangling the neoplastic chondrogenesis of two rare cartilaginous tumours

The scope of this study was to disentangle neoplastic chondrogenesis in two rare cartilaginous tumours: chondroblastoma and chondromyxoid fibroma. It was addressed: 1 The spectrum of phenotypic differentiation in chondroblastoma and chondromyxoid fibroma, 2 The signalling pathways driving chondroblastoma and chondromyxoid fibroma pathogenesis, 3 The somatic genetic background underlying chondroblastoma and chondromyxoid fibroma. The findings of this study and the literature suggest that chondroblastoma and chondromyxoid fibroma may originate from a mesenchymal stem cell precursor. An as yet unknown genetic event may induce neoplastic transformation and: 1) on the one hand activate signalling cascade crucial for neoplastic cell survival (i.e. PTHLH, TGF-_, etc.) and commit cells towards cartilage (expression of cartilage-specific molecules), 2) on the other hand activate an expression profile of __non-cartilage specific__ molecules distinct for chondroblastoma and chondromyxoid fibroma, respectively . Subsequently __passenger-related__ structural changes are hypothesized to occur