Primary intracranial EWSR1-FLI1 fusion-positive Ewing's sarcoma:report of a case and review of literature
LU Yun-long
NIU Hai-yan
HONG Chao
YANG Cheng
Abstract：Primary intracranial Ewing sarcoma (ES) is an extremely rare malignant tumor, mostly occurring in children and adolescents. Due to its rarity, the magnetic resonance imaging (MRI) features and treatment strategies of primary intracranial ES remain unclear. One case of primary intracranial ES was collected from the First Affiliated Hospital of Hainan Medical University in 2023. Clinical and imaging manifestations, gross characteristics, microscopic changes were observed. Immunohistochemistry and fluorescence in situ hybridization (FISH) detection techniques were used, combined with literature analysis. The patient was a 33-year-old male who was admitted due to symptoms such as blurred vision in both eyes and pain in the right occipital region without obvious cause. Laboratory examination: cranial MRI showed a cystic-solid lesion in the right occipital region, well-defined, regular in shape, with a maximum diameter of 5.9 cm. Under the microscope, the tumor cells were arranged in nests or sheets, with small, round or oval nuclei, deeply stained, and densely packed, with frequent mitotic figures. Immunohistochemistry showed CD99 and FLi-1 positive, Ki-67 positive (80%). EWSR1-FLI1 fusion probe was positive. Primary intracranial ES in young adults is very rare. Diagnosis depends on histopathology, immunohistochemical staining, and genetic testing. Currently, complete tumor resection combined with radiotherapy and chemotherapy is the most effective treatment.
Keywords：IntracranialYoung adultsEwing sarcomaEWSR1-FLI1 fusionDiagnosis and differential diagnosis
Publication Date：2025-04-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：3( 463-464,468 )