The imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumors (pPNETs).

The British journal of radiology

PubMedID: 24988215

Jing Z, Wen Yi L, Jian Li L, Jun Lin Z, Chi D. The imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumors (pPNETs). Br J Radiol. 2014;20130631.
Objective: To explore the imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumors (pPNETs). Methods: The imaging features and pathological characteristics of eight cases of surgically and pathologically confirmed Ewing sarcoma/pPNET were analyzed retrospectively in light of recent literature on the disease. Results: The peak age was between 10 and 20. The lesions tended to be spindle-shaped and dural-based, usually widely so. CT showed the lesions were slightly uneven high density in 5 cases, iso-low mixed density in 3 cases; marked heterogeneous enhancement was seen in all cases after contrast injection. Magnetic resonance imaging of the lesions showed varying proportions of isointense and hypointense signal in all cases on unenhanced T1-weighted imaging, and varying proportions of isointense and hyperintense signal on T2-weighted imaging. After contrast injection, marked heterogeneous enhancement was seen in all cases; three cases showed a short and nodular dural tail and five cases showed adjacent skull erosion and osteolysis. Pathological results included high cell density, hemorrhage, and necrosis. The cells resembled lymphocytes and spindle cells with transparent cytoplasm. CD99 and vimentin were expressed by all tumor cells. Conclusion: Features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumors (pPNETs) include peak incidence in the second decade, a broad connection to the meninges, a thick dural tail involved with tumor, skull and scalp erosion, and early metastasis. Necrosis and cystic changes are common histological findings. Advances in knowledge: The imaging features of meningeal Ewing sarcoma/pPNETs have not been reported. The study helps to identify meningeal Ewing sarcoma/pPNETs and meningioma.