C-Kit-Negative Gastrointestinal Stromal Tumor in the Stomach

C-kit-negative gastrointestinal stromal tumors (GISTs) are uncommon, and there have been few reports about the diagnosis and treatment of c-kit-negative GISTs in the stomach. We report the case of a patient who was diagnosed with a huge and atypical GIST in the stomach. The GIST was completely resected and finally diagnosed as c-kit-negative GIST based on immunohistochemical staining of tumor cells, which were negative for CD117 and CD34 and positive for Discovered on GIST-1 (DOG1). C-kit-negative GISTs could be treated by complete resection and/or imatinib, which is the same treatment for c-kit-positive GISTs.

The expression of DOG1 in gastrointestinal stromal tumors / 中华普通外科杂志

Objective To evaluate DOG1 as an immunohistochemical marker for GIST.Methods From Jan 1987 to Sep 2008,210 consecutive cases including 137 GISTs as well as 73 non-GIST sarcoma were evaluated for clinicopathological characteristics and immunostained for DOG1 antibodies.Result Immunoreactivity for DOG1 was detected in 110 of 137 GIST cases (80.3%),3 out of 11 CD117negative GISTs were DOG1-positive.Only 1 of 73 non-GIST case was positive for DOG1.The expression of DOG1 in GIST is associated with the location of tumor,cell density,nuclear pleomorphism and Fletcher grading criteria.The postoperative 1-,3-,5-year overall survival for DOG1 negative and positive patients was 81.3%,74.5%,74.5% and 98.5%,85.9%,83.2%,respectively,P = 0.034.Conclusion DOG1 was a sensitive and specific marker for GIST in gastrointestinal mesenchymal tumors (GIMT).