The roentgen ray is one of the most valuable, if not the most valuable, aid in the diagnosis and prognosis of sarcoma of the long bones. It reveals the location, size and extent, and to a certain degree, the structure and origin of the tumor and the presence of metastasis. It is the earliest aid in determining the presence of pulmonary metastasis, although the absence of demonstrable lesions does not mean that metastasis has not occurred. Roentgenograms of the lungs should be made as a routine measure in every case of suspected malignant tumor of the long bones, particularly if surgery is contemplated for removal of the primary tumor.

Various types of sarcoma, central or periosteal, with marked differences in density, structure, and location may be observed roentgenographically. The roentgenographic appearance of these types, while not always characteristic, is, nevertheless, fairly characteristic and yields a high percentage of accurate diagnoses. Operation should seldom be resorted to, and amputation never, without exploratory operation with the use of the tourniquet, and microscopic proof of malignancy. There may be exceptions when the member or joint is already so far involved that it is obvious that the extremity cannot be saved.

While the roentgen-ray examination is a valuable aid in diagnosis, the history and clinical findings and, whenever possible, exploration of the tumor, and its gross and microscopic appearance must be considered in determining the diagnosis, prognosis, and treatment. The prognosis, always grave, is hopeless with definite pulmonary metastasis demonstrated in the roentgenogram.