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Expression of ETV6‐NTRK in classical, cellular and mixed subtypes of congenital mesoblastic nephroma
Author(s) -
Anderson J,
Gibson S,
Sebire N J
Publication year - 2006
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/j.1365-2559.2006.02400.x
Subject(s) - biology , taqman , fusion gene , real time polymerase chain reaction , phenotype , pathology , polymerase chain reaction , reverse transcription polymerase chain reaction , gene expression , reverse transcriptase , gene product , immunohistochemistry , microbiology and biotechnology , gene , medicine , genetics
Aim: Congenital mesoblastic nephroma (CMN) is the commonest renal tumour of infancy, with classical, cellular and mixed histological subtypes described. A specific ETV6‐NTRK3 fusion‐gene product is reported in association with the cellular variant. The aim was to investigate the relationship between the presence of this product and morphological phenotype using paraffin‐embedded archival material. Methods and results: Cases of CMN from a single centre during a 15‐year period (1989–1994) were identified, anonymized and blindly classified using morphological criteria. RNA was extracted from frozen and paraffin sections for both conventional reverse transcriptase‐polymerase chain reaction (RT‐PCR) and quantitative real‐time RT‐PCR. Fifteen samples were analysed; two were non‐informative and three expressed ETV6‐NTRK3 using both techniques, two showing similar expression, whilst one showed expression two orders of magnitude lower, from a cellular tumour. All fusion positive cases were previously classified as cellular subtype. Six patients had mixed‐subtype tumours in which the cellular components, morphologically indistinguishable from cellular tumours, were fusion negative, as were all classical cases. Conclusions: Real‐time PCR Taqman assays, using both fixed and frozen tissue, provide highly reproducible detection and quantification of fusion transcript expression. Differences in expression levels may explain previous conflicting data on fusion gene detection in these tumours.