Diaphyseal telangiectatic osteosarcoma as a second tumor after bilateral retinoblastomas.

In this report, we describe the clinical, imaging, and pathologic findings in a case of diaphyseal telangiectatic osteosarcoma arising 23 years after successful treatment of bilateral retinoblastomas. To our knowledge, telangiectatic osteosarcoma occurring as a second tumor in this setting, outside the radiation treatment field, has not been previously reported. The association of the RB-1 gene defect with retinoblastomas and other tumors is discussed. Also, the computed tomography and magnetic resonance imaging findings in telangiectatic osteosarcoma are described and discussed.