title: Ewing sarcoma presenting as a subconjunctival mass.
abstract: A 14-year-old previously healthy boy presented for evaluation of a subconjunctival mass that had been present for 2 to 3 years, but had recently started to enlarge. Imaging demonstrated an anterior orbital lesion that enhanced with gadolinium. An excisional biopsy was performed and revealed highly malignant-appearing small, blue, round tumor cells. Immuohistochemical stains were strongly reactive with CD99 (MIC2 and O13), CD56, and retained INI-1 reactivity. The EWS-FLI1 chimeric fusion gene transcript was also detected by reverse transcription-polymerase chain reaction analysis, confirming Ewing sarcoma. Full-body CT, bone scan, and bone marrow biopsy were all negative, proving this to be a premetastatic, primary orbital tumor arising from soft tissue.
authors.affiliation: Children's Hospital of Philadelphia, University of Pennsylvania Hospital System, Philadelphia, Pennsylvania 19104-4399, USA. katelane@verizon.net
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Lane
authors.forename: James A
authors.initials: JA
authors.lastname: Katowitz
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000032:analysis; D003230:Conjunctival Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000601:surgery; D005682:Gadolinium; D006801:Humans; D007124:Immunoenzyme Techniques; D008279:Magnetic Resonance Imaging; D008297:Male; D009918:Orbital Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000601:surgery; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000737:chemistry / Q000175:diagnosis* / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor; D005682:Gadolinium