Secondary Thyroid Papillary Carcinoma in Osteosarcoma Patients: Report of Two Cases

We report two cases of papillary thyroid carcinoma occurring after the successful treatment of osteosarcoma. One of the patients was administered with several alkylating agents and topoisomerase II inhibitor as part of the primary treatment of osteosarcoma. The onset of thyroid carcinoma occurred after 5 and 12 yr after cessation of the osteosarcoma therapy. All the patients involved in this study are alive and free of their malignancies. There have been eight case reports of these two malignancies occurring in the same patient. Thyroid carcinoma rarely occurs in patients with osteosarcoma; however, vigilant surveillance and long-term follow-up should be emphasized for all survivors.