Receptor tyrosine kinases in sinonasal undifferentiated carcinomas--evaluation for EGFR, c-KIT, and HER2/neu expression.
BACKGROUND
Our objective was to identify the expression of epidermal growth factor receptor (EGFR), c-KIT (CD117), and HER2/neu in sinonasal undifferentiated carcinoma (SNUC).


METHODS
Immunohistochemistry for c-KIT (CD117), EGFR, and HER2/neu was performed on paraffin-embedded tissue from SNUC cases. A search for activating mutations in c-kit exons 9, 11, 13, and 17 or gene amplification was undertaken by high-resolution DNA melting curve analysis and fluorescence in situ hybridization (FISH) for c-kit and chromosome 4, respectively.


RESULTS
By immunohistochemistry, 9 of 11 cases (81.8%) were diffusely (4+) positive for c-KIT, 3 of 11 cases (27.3%) were positive for EGFR, and none of the cases were positive for HER2/neu. Neither activating mutations nor gene amplification of c-kit were detected in any of the 8 assessable tumors.


CONCLUSIONS
c-KIT is frequently expressed in SNUC. However, the overexpression is not due to activating mutations or gene amplification.
Chernock
Rebecca D
RD
Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA.
Perry
Arie
A
Pfeifer
John D
JD
Holden
Joseph A
JA
Lewis
James S
JS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D010255:Paranasal Sinus Neoplasms / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology*; D012189:Retrospective Studies
D020794:Receptor Protein-Tyrosine Kinases