Imaging findings in paraspinal extra osseous Ewing sarcoma.

We present a case of extraskeletal Ewing sarcoma (ES) in a 32-year-old male patient. The patient reported a painful mass in the thoracic paraspinal area which reached a considerable size in a one-month interval. Sonography and CT showed a heterogeneous, hypoechoic/hypodense soft tissue mass embedded in the dorsal paraspinal musculature. MRI with contrast enhancement showed a solid tumor surrounding areas of necrosis/cystic degeneration. Despite wide contact with the spine and ribs there was no intrathoracic/intraspinal extension or neural foraminal invasion. The imaging findings are non specific; a paravertebral location in the appropriate age group may be the clue to the diagnosis of extraskeletal ES.