Radiological findings in children with primary mediastinal Ewing sarcoma/primitive neuroectodermal tumors: a retrospective case series study.

The goal of this study was to summarize the radiological findings and clinical characteristics of mediastinal Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) in children. A retrospective review was conducted on the clinical and imaging data of 6 children with primary mediastinal ES/PNET that was confirmed by pathology. There were 3 girls and 3 boys in this study, aged between 2 and 11 years old. The tumors exhibited a range of maximum diameters for each child, spanning from 3.8 to 16.0 cm, and the boundaries of 6 tumors were unclear. Furthermore, the tumors were located in the posterior mediastinum in 2 cases, in the mid-posterior mediastinum in 3 cases, and in the anterior middle posterior mediastinum in 1 case. Necrosis and cystic degeneration were found in all 6 cases, and calcification was found in 2 cases, and the solid part of the tumors showed moderate heterogeneous progressive enhancement. The spinal epidural was involved in 2 cases; adjacent ribs were invaded in 2 cases; the adjacent vertebral body and appendage were invaded in 1 case, and the chest wall was invaded in 4 cases. Finally, pleural effusion occurred in 4 cases, including 1 case with pericardial effusion; 3 patients with pleural metastasis. In conclusion, the computed tomography (CT) findings of primary ES/PNET originating in childhood show a level of distinctiveness that facilitates their identification.