Squamous cell carcinoma of the larynx with osteosarcoma-like stromal metaplasia.

Osseous or chondroid metaplasias are uncommonly found adjacent to laryngeal squamous cell carcinoma (SCC). These findings are less unusual in the spindle cell variant. We describe a moderately differentiated laryngeal SCC associated with osteocartilaginous metaplasia of the adjacent stroma which exhibited very similar morphologic changes and mitoses to an osteosarcoma. These uncommon findings can be more clearly understood if they are viewed as changes determined by the microenvironment of the tumour-host interface, as indicated in recent studies. Tumour cells seem able to regulate stromal development and differentiation via the release of growth factors and the induction of growth factor receptor expression on the cell surface. Irrespective of the limited number of reported cases, the association of SCCs of the larynx with osteocartilaginous metaplasia does not seem to support the adoption of treatments of choice that differ in approach to those for site- and stage-matched SCCs without osteocartilaginous metaplasia.