Dedifferentiated chondrosarcoma of the larynx

Abstract

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.

fig 1.

A, Soft-tissue window axial contrast-enhanced CT through thyroid cartilage shows expansile lesion from left alar of thyroid cartilage. Multiple rings, calcification arcs, and relatively intact cortex suggest chondroid lesion. False cord is significantly displaced. Note large soft-tissue component extending anterolaterally into strap muscles and incomplete cortex at point (arrows). B, Bone window of expansile lesion shown in panel A. C, Bone window axial CT scan obtained through vocal cord level shows mass representing typical chondroid lesion with multiple rings and calcification arcs (arrow) and well-preserved cortex at this level. D, Histologic section from laryngectomy specimen shows features of dedifferentiated chondrosarcoma. Area of low-grade chondrosarcoma is on left, juxtaposed to malignant fibrous histiocytoma-like area of high-grade sarcoma on right (H&E, original magnification ×125).