Ahmed-Emad Mahfouz MD, Presenter: Nothing to Disclose

Hanan Sherif MD, Abstract Co-Author: Nothing to Disclose

Hassan Abdulla Alansari MBBCh, Abstract Co-Author: Nothing to Disclose

Batoul Mashhadi MD, Abstract Co-Author: Nothing to Disclose

Ewing sarcoma/primitive neuroectodermal tumor (PNET) may originate in different parts of the body within or outside the skeleton. Purely extraskeletal Ewing/PNET may represent a diagnostic challenge entering into the differential diagnosis of lesions in the anatomical location. Examples presented here are Ewing/PNET of the carotid sheath and the anterior abdominal wall. Predominently extraskeletal soft tissue Ewing/PNET located adjacent to bone may have a subtle bony projection  into the soft tissue mass, which gives a clue to the diagnosis.  Predominently skeletal Ewing/PNET classically involves the diaphysis in children. It shows the classical onion-peel periosteal reaction and may extend outside bone forming a soft tissue mass. Ewing/PNET tends to cross anatomical boundaries without complete destruction, leaving a ghost of the anatomical structure (particularly bone) while spreading on both sides of it.    

Ewing/PNET with full radiologic-pathologic correlation Purely skeletal Predominently skeletal with soft tissue extension after cortical disruption Predominently extraskeletal with subtle nidus related to the adjacent bone Predominently extraskeletal with spread through the bone forming the typical bone "ghost" with soft tissue masses on both sides Purely extraskeletal 

http://abstract.rsna.org/uploads/2014/14015218/14015218_u5oh.pdf

Mahfouz, A, Sherif, H, Alansari, H, Mashhadi, B, Skeletal and Extraskeletal Ewing Sarcoma/Primitive Neuroectodermal Tumor.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015218.html