Primary osteosarcoma of the uterus with cardiac and pulmonary metastases

•This is the first reported case describing a female with primary uterine osteosarcoma that exhibited cardiac and pulmonary metastases.•Although extremely rare, uterine osteosarcomas, like leiomyosarcomas, do respond to doxorubicin and ifosfamide.•Uterine osteosarcoma behaves aggressively and is associated with a poor prognosis.