Gastrointestinal stromal tumor(GIST)is the most common mesenchymal malignancy of the gastrointestinal tract.GISTs may coexist with different types of cancer,either synchronous or metachronous(1).Most GISTs develop in a sporadic fashion,but familial occurrence,such as neurofibromatosis and Carney-triad,has also been reported(2).The overall frequency of second tumors in different series varied
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