title: Friend leukaemia integration-1 expression in malignant and benign tumours: a multiple tumour tissue microarray analysis using polyclonal antibody.
abstract: BACKGROUND
  Friend leukaemia integration-1 (FLI-1) antibody is a useful marker for Ewing's sarcoma/primitive neuroectodermal tumour (EWS/PNET) and vascular tumours. However, it is also expressed in subsets of lymphoblastic lymphoma, Merkel cell carcinoma (MCC) and desmoplastic small round cell tumour (DSRCT).
  
  
  OBJECTIVE
  To determine expression of FLI-1 in various benign and malignant neoplasms, by immunohistochemical analysis on 4323 tumours using multiple tumour microarrays, as well as on whole sections.
  
  
  RESULTS
  FLI-1 was expressed in 46/62 EWS/PNETs, 2/3 olfactory neuroblastomas, 7/102 small cell carcinomas of the lung, 10/34 MCCs, 1/14 rhabdomyosarcoma, 19/132 non-Hodgkin's lymphomas, 2/3 DSRCTs, and in 53/74 benign and malignant vascular tumours. In addition, 27/508 squamous cell carcinomas, 19/837 adenocarcinomas, 10/400 urothelial bladder cancers, 1/40 basal cell carcinomas, 3/29 liposarcomas, 1/40 glioblastoma multiforme and 9/29 medullar carcinomas of the breast expressed FLI-1. The sensitivity and specificity of FLI-1 to distinguish EWS/PNET from all types of malignancies were 74.2% and 96.0%, respectively. Finally, the sensitivity and specificity of FLI-1 to distinguish EWS/PNET from other small round cell tumours (SRCTs) were 74.2% and 91.6%, respectively.
  
  
  CONCLUSIONS
  This study was the first to show that FLI-1 can be seen in a variety of solid tumours, some of which had never been explored before. This finding should be kept in mind, especially when using FLI-1 as a marker for finding the primary origin of poorly differentiated metastatic tumour. Finally, despite the expression of FLI-1 in numerous malignancies, it is still considered to be highly sensitive and specific in distinguishing EWS/PNET from other tumour types in general and from other SRCTs in particular.
authors.affiliation: Department of Pathology and Laboratory Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263, USA. pmhawech1@yahoo.com
authors.forename: Paulette
authors.initials: P
authors.lastname: Mhawech-Fauceglia
authors.forename: Francois R
authors.initials: FR
authors.lastname: Herrmann
authors.forename: Wiam
authors.initials: W
authors.lastname: Bshara
authors.forename: Kunle
authors.initials: K
authors.lastname: Odunsi
authors.forename: Luigi
authors.initials: L
authors.lastname: Terracciano
authors.forename: Guido
authors.initials: G
authors.lastname: Sauter
authors.forename: Richard T
authors.initials: RT
authors.lastname: Cheney
authors.forename: Jeff
authors.initials: J
authors.lastname: Groth
authors.forename: Remedios
authors.initials: R
authors.lastname: Penetrante
authors.forename: Paulette
authors.initials: P
authors.lastname: Mhawech-Fauceglia
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000378:metabolism; D003937:Diagnosis, Differential; D006801:Humans; D007124:Immunoenzyme Techniques; D009369:Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis / Q000378:metabolism; D018242:Neuroectodermal Tumors, Primitive / Q000175:diagnosis / Q000378:metabolism; D040081:Protein Array Analysis / Q000379:methods; D051789:Proto-Oncogene Protein c-fli-1 / Q000378:metabolism*; D012512:Sarcoma, Ewing / Q000175:diagnosis / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D051789:Proto-Oncogene Protein c-fli-1