Primary chondroblastic osteosarcoma of the lung.

Purpose. Primary extra-osseous osteosarcomas are uncommon lesions, and those originating within the lung are especially rare, with few case reports existing in the literature.Patient. We report the case of a 48-year-old male smoker with a primary osteosarcoma of the right lower lung lobe.Results. Diagnosis was based on histopathological findings of a poorly differentiated sarcoma with malignant cellular components of osteoid and chondroid matrix, along with immunohistochemical and electron microscopy confirmation. Extensive clinical and radiographic evaluation failed to reveal any tumor at other anatomical sites.