KIT and sarcomatoid carcinoma: It is worth mentioning that both carcinosarcomas, sarcomatoid carcinomas, and spindle cell carcinomas are different from other biphasic tumors, such as some collision tumor, gastroblastoma, synovial sarcoma, and teratoma.[8,22,23] A carcinosarcoma case was reported with C-kit expression[19] and its sarcoma cells were partly and weakly positive for CD117, but no C-kit mutation was detected in exons 9, 11, 13, and 17, so the evidence was not sufficient to diagnose gastric carcinosarcoma with GIST, but carcinosarcoma with C-kit expression.