Dural Metastasis of Ewing’s Sarcoma arteries. Relatively lower signal intensity within the mass on T2-weighted imaging usually suggests hypercellularity, as is generally found in meningioma, lymphoma or leukemia. Ewing’s sarcoma is also in the category of hypercellular tumors, and this hypercellularity is evident in both primary and secondary tumors. The lack of bone involvement supports the possibility of hematogenous spread of the dural lesion in our patient. In addition, although it was not confirmed pathologically, a new dural lesion was detected on follow-up imaging, raising the possibility that the prior lesion had the same mode of spread. In conclusion, dural metastasis of Ewing’s sarcoma is very rare and its imaging characteristics are similar to those of a primary tumor, which mimic the findings of a schwan- noma or meningioma. Despite its rarity, secondary Ewing’s sarcoma may be included in the differential diagnosis of extra-axial dural masses. References 1. Pizo P, Poplack D. Ewing’s sarcoma of bone and soft tissue: principles and practice of pediatric oncology, 3rd ed. Philadelphia: JB Lippincott, 1996:840-841 2. Postovsky S, Ash S, Ramu IN, Yaniv Y, Zaizov R, Futerman B, et al. Central nervous system involvement in children with sarcoma. Oncology 2003;65:118-124 3. Shuper A, Cohen IJ, Mor C, Ash S, Kornreich L, Zaizov R. Metastatic brain involvement in Ewing family of tumors in children. Neurology 1998;51:1336-1338 4. Li WY, Brock P, Saunders DE. Imaging characteristics of primary cranial Ewing sarcoma. Pediatr Radiol 2005;35:612- 618 5. Mehta Y, Hendrickson FR. CNS involvement in Ewing’s sarcoma. Cancer 1974;33:859-862 6. Marciani MG, Stefani N, Peroni L, Stefanini F, Tarantino U, Gigli GL, et al. Intracerebral metastasis in Ewing’s sarcoma. Acta Neurol Belg 1990;90:149-156 7. Meyer PC, Reah TG. Secondary neoplasms of the central nervous system and meninges. Br J Cancer 1953;7:438-448 8. Kleinschmidt-DeMasters BK. Dural metastases. A retrospective surgical and autopsy series. Arch Pathol Lab Med 2001;125:880-887 9. Pekala JS, Gururangan S, Provenzale JM, Mukundan S Jr. Central nervous system extraosseous Ewing sarcoma: radiologic manifestations of this newly defined pathologic entity. AJNR Am J Neuroradiol 2006;27:580-583 10. Dirks PB, Harris L, Hoffman HJ, Humphreys RP, Drake JM, Rutka JT. Supratentorial primitive neuroectodermal tumors in children. J Neurooncol 1996;29:75-84 Korean J Radiol 9(1), February 2008 79