ABSTRACT
Objective To explore the CT features in CD_(117)-weak and CD_(117)-negative gastrointestinal stromal tumors(GIST).Methods The CD_(117)-weak and CD_(117)-negative Gist proved by pathologically and sur- gically in 13 cases were retrospectively analyzed.Results The tumor was located in the stomach in 6 cases, small intestine in 4 cases,colorectum in 2 cases,greater omentum in one case.The most common clinical manifestations were abdominal pain or discomfort in 6 cases,hematemesis or melena in 3 cases.Malignant tu- mors occurred in 8 cases.Benign tumors occurred in 5 cases.A soft tissue was identified in all 13 cases in CT examination.The CT examinations revealed cystic regions and bleeding in 5 cases.Calcification was not noted within the masses in all cases.The mean diameter of benign tumors was 3.4 cm?2.8 cm while that of malig- nant tumor was 7.5 cm?6.2 cm.All the cases underwent operation,the resection rate was 100%.After follow up from 6 months to 4 years in 10 cases,1 case died of tumor recurrence and metastasis,the others survived. Conclusion CD_(117)-weak and CD_(117)-negative Gist occurred more common in the stomach.CT is useful in lo- cation and differentiation of CD_(117)-weak and CD_(117)-negative gastric stromal tumors with regard to benign or malignant.Surgery is the main method for final diagnosis and treatment.