Dedifferentiated chondrosarcoma of the larynx.

A 74-year-old man with a history of a chondroid lesion of the larynx noted an enlarging neck mass. Axial CT showed a large expansile lesion arising from the left thyroid cartilage. Multiple rings and arcs with relatively intact cortex indicated a chondroid lesion. Irregularity of the anterolateral margin abutted a prominent soft-tissue component. The specimen obtained from fine needle aspiration was suggestive of a malignant fibrous histiocytoma. After further resection, the final diagnosis was dedifferentiated chondrosarcoma. A new soft-tissue component or rapid growth of the mass can be indicative of a diagnosis of dedifferentiated chondrosarcoma.