Diagnostic utility of FLI-1 monoclonal antibody and dual-colour, break-apart probe fluorescence in situ (FISH) analysis in Ewing's sarcoma/primitive neuroectodermal tumour (EWS/PNET). A comparative study with CD99 and FLI-1 polyclonal antibodies.
OBJECTIVE
To compare the sensitivity and specificity of the recently commercially available FLI-1 monoclonal (FLI-1m) antibody with the currently used antibodies [CD99 and FLI-1 polyclonal (FLI-1p)] in the diagnosis of Ewing's sarcoma/primitive neuroectodermal tumour (EWS/PNET) and to determine the diagnostic value of the EWSR1 (22q12) dual-colour, break-apart rearrangement probe fluorescence in situ hybridization (FISH) technique.


METHODS
Forty-three cases of well-documented EWS/PNET and 15 non-EWS/PNET cases were retrieved from the archival files. Immunohistochemistry (IHC) for FLI-1p, FLI-1m and FISH analysis was performed.


RESULTS
The most sensitive and specific test panel for the diagnosis of EWS/PNET is the combination of CD99 and FLI-1p. FISH had a very high specificity (100%) but only a moderate sensitivity (50%).


CONCLUSIONS
The combination of CD99 and FLI-1p is the method of choice for the diagnosis of EWS/PNET. EWRS1 (22q12) dual-colour, break-apart rearrangement probe FISH should be used as a confirmatory test in addition to CD99 and FLI1-p due to its high specificity.
Mhawech-Fauceglia
P
P
Department of Pathology and Laboratory Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA. pmhawech1@yahoo.com
Herrmann
F
F
Penetrante
R
R
Beck
A
A
Sait
S
S
Block
A M
AM
Odunsi
K
K
Fisher
J
J
Balos
L
L
Cheney
R T
RT
D000071443:12E7 Antigen; D000199:Actins; D000465:Algorithms; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology*; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D008840:Microfilament Proteins / Q000235:genetics* / Q000276:immunology*; D009363:Neoplasm Proteins / Q000276:immunology; D018242:Neuroectodermal Tumors, Primitive / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D011237:Predictive Value of Tests; D012372:ROC Curve; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000276:immunology*; D012512:Sarcoma, Ewing / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D015534:Trans-Activators
D000071443:12E7 Antigen; D000199:Actins; D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D015703:Antigens, CD; D014408:Biomarkers, Tumor; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; C098179:FLII protein, human; D008840:Microfilament Proteins; D009363:Neoplasm Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators