Abstract
A fifteen-year-old boy, complaining of severe pain and swelling in the region of the right upper arm was referred to our hospital on June 14, 1971. About three and half months previously he had “bruised” this upper arm and complained painful swelling after a week, Roentgenographically osteosarcoma was suggested, but histologic appearance of this tumor was following; The tumor cells were separated by wide fibrdus septa. Nuclei were round and oval, and nucleoli were indistinct. Cytoplasm was scanty. Del Rio Hortega's silver-impregnant technique showed a lobular distribution of the reticular fibers circumscribing large areas of tumor cells, but few fibrils penetrated into tumor cells. “The periodic acid Schiff stain” was positive and previous digestion by takadiastase caused the periodic acid positive granules to disappear, thus we confirmed them glycogen and could diagnosed this tumor Ewing's sarcoma.
