Ewing's sarcoma with permeative growth through the haversian channels accompanied by a large soft tissue mass Ewing's sarcoma with permeative growth through the haversian channels accompanied by a large soft tissue mass Cortical destruction (3) In the group of malignant small round cell tumors which include Ewing's sarcoma, bone lymphoma and small cell osteosarcoma, the cortex may appear almost normal radiographically, while there is permeative growth throughout the Haversian channels.