Dedifferentiated chondrosarcoma of temporomandibular joint: atypical features of a rare case.

Chondrosarcoma (CS) is an uncommon malignant mesenchymal tumour showing cartilaginous differentiation which rarely presents in the jaws. CS represents 10-20% of all malignant bone tumours and less than 5% of tumours in head and neck region. Among the infrequent subtypes of CS, dedifferentiated CS is a sinister variant that presents with singular features and has extremely poor prognosis. We report a unique case of dedifferentiated CS that presented in the temporomandibular joint (TMJ) with extra articular involvement of the infratemporal space. This high grade CS is reviewed due to its rarity and the dentist is implored to take this variant into account when considering the differential diagnosis of destructive TMJ lesions.