Extraskeletal telangiectatic osteosarcoma.

The first three well-documented cases of pure, extraskeletal telangiectatic osteosarcoma of the soft tissues are presented in this article. The distinctive gross features were a predominance of large, blood-filled spaces, which, on histologic examination, were large blood-filled cavities in association with cyst-like walls containing anaplastic spindle cells and definite osteoid production in two of three cases. One of the cases is of additional clinical interest because the teen-aged daughter of the woman patient had died 1 year previously of a high-grade intramedullary osteosarcoma of bone.