Chondro myxoid fibroma of skull base- A pathological dilemma

Chondro-myxoid fibroma is relatively uncommon & is estimated to represent less than 1% of all primary bone neoplasms. Often seen in young adults during the second & third decades of life & usually arising from the metaphysis of major long bones of lower extremities. Head & Neck involvement remains a rare site & is thought to mainly arise from the synostosis at the base of skull or from sutures. This tumor may also arise from the embryonic cartilage residue. Jaffe & Lichtenstein in 1948 originally distinguished this tumor from other aggressive cartilaginous tumors. WHO defined it as a benign tumor characterized by lobules of spindle shaped or stellate cells with abundant myxoid or chondroid intercellular material separated by zones of more cellular tissue rich in spindle shaped or round cells with a varying number of multinucleated giant cells of different sizes. Establishing histological diagnosis of chondromyxoid fibroma involving skull base becomes all the more difficult because of its similarities with chondrosarcoma thus creating a trap for pathologists. Distinction between these two tumors is important due to their different management strategies. Here we present a case of chondromyxoid fibroma of right infra-temporal fossa treated by surgery alone, emphasizing more on the pathological aspects of diagnosis & differential diagnosis. A good knowledge of this clinical entity should avoid incorrect diagnosis.