Periosteal Ewing's sarcoma.

Periosteal Ewing's sarcoma is an uncommon, but well documented origin of this malignant condition with radiographic signs, different from intramedullary growing tumours. Imaging modalities like CT or MRI supply proof of macroscopically intact endosteal cortical surface and free medullary cavity in long bones affected by this periosteal type of malignancy. Definite confirmation is valid after a careful microscopic investigation of the resected specimen. The prognosis of this type of Ewing's sarcoma may be more favourable than that of the central type. Early diagnosis and therapy are thus essential. A clinical survey of six observations is given.