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

• Published in: Histopathology 2006-12, Vol.49 (6), p.569-575
• Main Authors: Mhawech-Fauceglia, P, Herrmann, F, Penetrante, R, Beck, A, Sait, S, Block, A M, Odunsi, K, Fisher, J, Balos, L, Cheney, R T
• Format: Article
• Language: English
• Subjects: 12E7 Antigen; Actins; Algorithms; Antibodies, Monoclonal - immunology; Antibodies, Neoplasm - immunology; Antigens, CD - immunology; Biological and medical sciences; Biomarkers, Tumor - analysis; Biomarkers, Tumor - genetics; Bone Neoplasms - diagnosis; Bone Neoplasms - genetics; Bone Neoplasms - immunology; CD99; Cell Adhesion Molecules - immunology; Chromosome Aberrations; Diseases of the osteoarticular system; EWS/PNET; Female; FISH; FLI-1m; FLI-1p; Humans; immunohistochemistry; In Situ Hybridization, Fluorescence - methods; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Microfilament Proteins - genetics; Microfilament Proteins - immunology; Neoplasm Proteins - immunology; Neuroectodermal Tumors, Primitive - diagnosis; Neuroectodermal Tumors, Primitive - genetics; Neuroectodermal Tumors, Primitive - immunology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Predictive Value of Tests; Receptors, Cytoplasmic and Nuclear - genetics; Receptors, Cytoplasmic and Nuclear - immunology; ROC Curve; Sarcoma, Ewing - diagnosis; Sarcoma, Ewing - genetics; Sarcoma, Ewing - immunology; Tumors of striated muscle and skeleton
• ISSN: 0309-0167; 1365-2559
• DOI: 10.1111/j.1365-2559.2006.02535.x

Aims:  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. Materials and 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%). Conclusion:  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.