title: Pre-B-cell acute lymphoblastic leukemia with bulk extramedullary disease and chromosome 22 (EWSR1) rearrangement masquerading as Ewing sarcoma.
abstract: We report a 2-year-old female with a subcutaneous tumor who was initially misdiagnosed as suffering from Ewing sarcoma with a positive EWSR1 rearrangement and EWS/FLI1 transcript. After finding lymphoblasts in peripheral blood, the diagnosis of acute lymphoblastic leukemia was established. This necessitated further analysis of the subcutaneous tumor. The tissue was positive for immature B-cell markers and an immunoglobulin heavy chain gene rearrangement, which confirmed the final diagnosis of common type acute lymphoblastic leukemia with bulk extramedullary disease. The patient was treated with chemotherapy and was in remission 30 months after the diagnosis.
authors.affiliation: Department of Hematology and Oncology, Pediatric Clinic, Children's Hospital Zagreb, Zagreb, Croatia. gordanajakovljevic@yahoo.com
authors.forename: Gordana
authors.initials: G
authors.lastname: Jakovljević
authors.forename: Melita
authors.initials: M
authors.lastname: Nakić
authors.forename: Srdan
authors.initials: S
authors.lastname: Rogosić
authors.forename: Ika
authors.initials: I
authors.lastname: Kardum-Skelin
authors.forename: Sanja
authors.initials: S
authors.lastname: Mrsić-Davidović
authors.forename: Renata
authors.initials: R
authors.lastname: Zadro
authors.forename: Bozo
authors.initials: B
authors.lastname: Kruslin
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002675:Child, Preschool; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000175:diagnosis*; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors