Gastrointestinal stromal tumor with a novel mutation of KIT proto-oncogene

The majority of human gastrointestinal mesenchymal tumors are gastrointesti nal stromal tumors (GISTs). Recent reports have shown the existence of gain -of-function mutations in the juxta-membrane domain of receptor tyrosine ki nase (KIT) in GISTs. We present a 77-year-old woman with GIST diagnosed by positive immunostaining of cluster designation (CD) 34 and KIT. This case h ad a novel mutation at codon 576 located in the juxta-membrane domain of KI T. Our results indicate the importance of mutations in this KIT region and suggest the possibility of the existence of other types of mutations in thi s region in GISTs.