Endoscopic And Immunohistochemical Characteristics Of Gastric Stromal Tumors: A Report Of80Cases

Objective: Gastric stromal tumor (GST) is the most common mesenchymaltumors of the digestive tract. The disease has no characteristic manifestations and thediagnosis lacks uniform standards. The lack of typical features of ultrasound, CT, MRIand other imaging examinations makes the definite diagnosis depending on pathologicaland immunohistochemical findings. In this study, in order to strengthen theunderstanding,provide the basis for biological behavior of the disease and find itearly,we investigated the clinical, endoscopic and immunohistochemical characteristicsin GST.Methods: Clinical datum of80cases with GST from March2002to October2011in the First Affiliated Hospital of Dalian Medical University which had been confirmedby pathological examination were analyzed retrospectively. All the cases had receivedendoscope(Olympus CV-260、H-260J) and16-slices CT scan, moreover, CEA levelswere tested preoperatively.According to the risk grading of Gastrointestinal StromalTumor (GIST) made by the National Institute of Health (NIH), the biological behaviorwas divided into4groups, which were very low risk group, low risk group, middle riskgroup and high risk group respectively. All cases received operation. The expression oftyrosine kinase receptors (CD117), bone marrow stem cell antigen (CD34), actin andsoluble acidic protein (S-100) were detected by two-step immunohistochemical method.The relationship between the indexes mentioned above and predilection site, size,biological behavior of the tumor were analyzed, and the relationship between tumor size,position, form and biological behavior under gastroscopy were investigated.Results1. Of all the80cases of GST, male and female cases counted24(52.5%) and16(47.5%) respectively. Age range:32-86years old, average age:62.4±11.8years old. Abdominal pain:31cases (38.8%), upper gastrointestinal bleeding:13cases (16.3%),abdominal mass:12cases (15.0%), abdominal distension:11cases (13.8%), weight loss:2cases (2.5%), fatigue:1case (1.3%), physical examination:10cases (12.5%).2. Preoperative endoscopic examination71cases were considered as GST and9cases were diagnosed chronic superficalgastritis. The lesion locations were as follows: gastric fundus counted31cases (43.7%),body of stomach counted25cases (35.2%), gastric antrum counted12cases (16.9%),cardia counted3cases (4.2%) respectively. Under gastroscopy the minimal diameter oflesion was0.3cm, the maximal diameter was10cm, the average diameter was3.4cm.Form under gastroscopy: semisphere eminentia43cases (60.6%), ulcer27cases (38.0%), polyp-like eminentia1case (1.4%). It showed significant differencebetween form under gastroscopy and biological behavior (P<0.05). There was noprominent difference among tumor size, predilection site and tumor biological behavior(P>0.05).3. CT diagnosis rateAll the80cases received CT scan.69cases were considered as GST (86.3%),8cases as gastric occupying (10%),2cases as gastric cancer (2.5%) and1case asleiomyoma (1.3%).4.Carcinoembryonic antigen (CEA) levels were tested preoperatively. Levels ofonly3cases(2.7%) were slightly higher than normal (0-3.4ng/ml), and levels of other77cases (96.3%) were all normal.5.Postopeartive pathological findingsGastric fundus:37cases (46.3%), body of stomach:27cases (38.8%), gastricantrum:13cases (16.3%), cardia:3cases (3.8%). Very low risk group:5cases (6.3%),low risk group:15cases (18.8%), middle risk group:45cases (56.3%), high risk group:15cases (18.8%). The minimal diameter of surgical specimens was0.2cm, the maximaldiameter was16cm, and the average diameter was6.0cm. CD117positive:79cases (98.8%), CD34positive:74cases (92.5%), S-100positive:9cases (11.3%), Actinpositive:7cases (8.8%). It showed significant difference between surgical specimens’sizes and tumor biological behavior (P<0.05). There was no remarkable differencebetween tumor predilection site and its biological behavior (P>0.05).It had no obviousdifferences between immunohistochemical indexes(CD117, CD34, Actin, S-100) andtumor predilection site and biological behavior (P>0.05). Conclusions1. Gastric stromal tumors predominantly occurred in middle aged to old people.The incidence rate between male and female was almost the same and the GST had notypical clinical manifestations. Carcinoembryonic antigen (CEA) may notprovide judgment to biological ethology of GST.2. The tumor biological behavior was associated with ulcer formation on thesurface of tumor，while there was no obvious relationship between tumor biologicalbehavior and its size under gastroscopy.3.Endoscopy had a relatively high sensitivity for GST diagnosis, and thecombination of CT and endoscope could raise the diagnostic rate of GST.4.The middle risk group had the highest GST frequence. The biologicalbehaviorwas significantly associated with tumor size. Immunohistochemicalindexes(CD117and CD34) had high positive rates, and were meaningful forthe diagnosis of GST，but have no obvious relationship with tumor biological behaviorand predilection site.