Extraosseous osteosarcoma with metastatic disease to the lungs

The patient is a 38-year-old female found to have a calcified nodule in the left breast (A, arrow). The CT scan of the chest in the transverse projection reveals three densely calcified nodules in the left lung (B, arrowheads). Following surgical excision of the breast mass, pathological evaluation revealed a diagnosis of extraosseous osteosarcoma. The morphological similarity of the lung nodules to the primary tumor on CT suggests metastatic extraosseous osteosarcoma to the lungs.