Skeletal and Extra Skeletal Ewing’s Sarcoma / Primitive Neuroectodermal Tumors(PNET): Clinicopathological Study

Background: To analyze the characteristics ofskeletal and extra skeletal Ewing’s sarcoma /Primitive Neuroectodermal Tumors PNET .Methods: In this descriptive cross-sectional studycases of skeletal and extra skeletal PNET wereanalyzed. Age, gender, site of biopsy, and results ofImmunohistochemistry were recorded.Results: Out of 80 cases, 65.4 % were males . Theage ranged from 1 to 45 years, with the mean age of18 years. Most frequent age group was the seconddecade of life(54 %). There were 37 cases of SkeletalEwing Sarcoma and 43 cases of Extra skeletal PNET.Among the 37 ( 47 % ) cases of Ewing sarcoma ofbone, femur (21.62%) was the commonest. Out of the43 cases of Extra skeletal PNET, 41 had peripheralPNET while 2 had CNS PNET. In the 41 patients ofPrimitive PNET, head and neck (18.6%) and chest(Askin Tumor) (16.27%) were the commonest. CD 99was positive in 73 %, while, NSE, and Cytokeratinwere positive in 32%. Periodic Acid Schiff waspositive in 53 cases.Conclusion: Extra skeletal (53.75%) involvementcomprises a larger number of cases as compared toskeletal Ewing’s sarcoma. Majority of the casespresent in the second decade of life. In skeletalEwing’s Sarcoma, femur is the commonest involvedsite. Head and neck and chest are the commonest inextraskeletal. In extraskeletal a propensity of the softtissue around leg is also observe