1. Investigation and study demonstrate that the same type scavenger giant cell is frequently present in lesions in bone that are purely inflammatory in character, as well as in true sarcomata of bone.
2. The term medullary giant-cell sarcoma should be abolished because it does not express the true underlying condition existing in bone lesions or neoplasms.
3. The diagnosis of sarcoma in bone should be made from the predominating structure the neoplasm contains, such as fibro-sarcoma, myxo-sarcoma, chondro-sarcoma, and osteo-sarcoma.
4. Granulation tissue proliferation filling in bone cavities should be recognized as an inflammatory and not a neoplastic process. It may be regarded as nature's effort at regeneration and repair.
Eight cases with brief histories and prints, illustrative of the subject of the paper, are appended herewith.