title: Primary alveolar rhabdomyosarcoma of the bone: two cases and review of the literature.
abstract: BACKGROUND
  Rhabdomyosarcoma (RMS) is a malignant tumor of mesenchymal origin and comprises the largest category of soft-tissue sarcomas both in children and adolescents. From a pediatric oncology point of view, RMS has traditionally been classified into alveolar (ARMS) and embryonal (ERMS) subtypes. The anatomical localization of the tumor may vary, but commonly involve the head/neck regions, male and female urogenital tract or the trunk and extremities.
  
  
  METHODS
  Here, we report two challenging cases involving 17- and 9-years-olds males where diffuse and multiplex bone lesions suggested either a hematological disease or a primary bone tumor (mesenchymal chondrosarcoma). Biopsies, proved a massive infiltration of the bone marrow cavity with rhabdomyosarcoma. In both cases, the ARMS subtype was confirmed using FOXO1 break-apart probes (FISH). Radiological examination could not identify primary soft tissue component in any localization at the time of diagnosis in either cases.
  
  
  CONCLUSIONS
  Primary alveolar rhabdomyosarcoma of the bone as a subtype of ARMS, seems to be a distinct clinico-pathological entity with challenging diagnostic difficulties and different, yet better, biological behavior in comparison to soft tissue ARMS. However, it is difficult to be characterized or predict its prognosis and long-term survival as only sporadic cases (four) were reported so far.
authors.affiliation: 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, Budapest, H-1085, Hungary.
authors.forename: Petra
authors.initials: P
authors.lastname: Balogh
authors.affiliation: 2nd Department of Pediatrics, Semmelweis University, Tűzoltó utca 7-9, Budapest, H-1094, Hungary.
authors.forename: Rita
authors.initials: R
authors.lastname: Bánusz
authors.affiliation: 2nd Department of Pediatrics, Semmelweis University, Tűzoltó utca 7-9, Budapest, H-1094, Hungary.
authors.forename: Monika
authors.initials: M
authors.lastname: Csóka
authors.affiliation: 2nd Department of Pediatrics, Semmelweis University, Tűzoltó utca 7-9, Budapest, H-1094, Hungary.
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Váradi
authors.affiliation: 2nd Department of Pediatrics, Semmelweis University, Tűzoltó utca 7-9, Budapest, H-1094, Hungary.|Magnetic Resonance Research Center, Semmelweis University, Tűzoltó utca 7-9, Budapest, H-1094, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Varga
authors.affiliation: 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, Budapest, H-1085, Hungary. sapi.zoltan.dr@gmail.com.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Sápi
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001706:Biopsy; D001859:Bone Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D002648:Child; D018450:Disease Progression; D017809:Fatal Outcome; D000071161:Forkhead Box Protein O1 / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008279:Magnetic Resonance Imaging; D008297:Male; D018008:Myogenin / Q000032:analysis; D011237:Predictive Value of Tests; D018232:Rhabdomyosarcoma, Alveolar / Q000737:chemistry / Q000188:drug therapy / Q000235:genetics / Q000556:secondary*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; C503799:MYOG protein, human; D018008:Myogenin
keywords: Alveolar rhabdomyosarcoma of bone; Clinico-pathological entity; FOXO-1