Validation of tissue microarray technology in malignant peripheral nerve sheath tumours
- K Soares Gonçalves Cunha1,2,3,
- A Cunha Caruso4,
- A Soares Gonçalves1,
- V Gonçalves Bernardo1,
- A Rodrigues Cordovil Pires1,
- E Carvalho da Fonseca1,
- P Antônio Silvestre de Faria4,
- L Esmeraldo da Silva1,
- M Geller3,5,6,
- R Soares de Moura-Neto7,
- V Silami Lopes1
- 1Postgraduate Program of Pathology, School of Medicine, Fluminense Federal University (UFF), Niterói, Rio de Janeiro, Brazil
- 2School of Dentistry, Nova Friburgo University Pole, Fluminense Federal, University (UFF), Nova Friburgo, Rio de Janeiro, Brazil
- 3Postgraduate Program of Medicine, Carlos Chagas Institute, Rio de Janeiro, Brazil
- 4Pathology Division, National Institute of Cancer (INCA), Rio de Janeiro, Brazil
- 5Department of Microbiology and Immunology, Teresópolis Medical School (UNIFESO), Teresópolis, Rio de Janeiro, Brazil
- 6Department of Clinical Genetics, Martagão Gesteira Institute of Puericulture and Pediatrics, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- 7Department of Genetics, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Dr K Soares Gonçalves Cunha, Rua Marquês do Paraná, 303 - 4° andar - sala 1 - Centro, Niterói, Rio de Janeiro, Brazil 24033-900; karingoncalves{at}terra.com.br
- Accepted 13 March 2009
- Published Online First 23 March 2009
Abstract
Background: It has been suggested that the donor tissue cores used in tissue microarrays (TMAs) may not be representative of the whole tissue section.
Aim: To validate the use of TMA technology in the study of malignant peripheral nerve sheath tumours (MPNSTs).
Methods: A TMA was constructed containing five independent core biopsy samples of 14 formalin-fixed, paraffin-embedded MPNSTs. The immunohistochemical (IHC) results of the five cores from the same tissue block on TMA were compared with readings from whole sections using two antibodies: anti-Ki-67 and anti-S-100. Digital image analysis was performed to calculate the percentage of positive stain areas. The agreement between IHC results obtained with TMA cores and whole sections was assessed using the κ statistic.
Results: There was good to very good agreement between IHC results for whole and TMA sections from MPNSTs. In relation to S-100, very good agreement (92% agreement; κ = 0.77) was observed using a minimum of four TMA cores. Staining results for Ki-67 from at least four readable TMA cores were the same as those for the whole section in 86% of cases, with good agreement, using weighted κ statistics (κ = 0.63).
Conclusions: This study indicates that the TMA technique can be used in the IHC study of MPNSTs, even with the use of heterogeneous markers such as S-100 protein.
Footnotes
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Competing interests: None.
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Ethics approval: Obtained.
