gastrointestinal stromal tumor ( gist ) is a gastric submucosal tumor ( smt ) , originating from the interstitial cells of cajal . around 40% of gists gastric gist is treated with surgery , including laparoscopy , endoscopic mucosal resection , or endoscopic submucosal dissection , and imatinib is also used for the treatment of gist . for appropriate treatment , there are several markers that are useful for the diagnosis of gist , such as cd34 , cd117 , and ki-67 . kit gene mutation is a feature of gist , and patients with gist , along with kit gene mutation , have a poor prognosis . ki-67 is involved in cell proliferation , and its high expression correlates with poor prognosis of gist . to exert the above analysis eus - guided fine needle aspiration ( eus - fna ) enables histological evaluation , leading to the pathological diagnosis of gastric gist . there are three sizes of needles available for this procedure : 19-gauge ( 19 g ) , 22-guage ( 22 g ) , and 25-guage ( 25 g ) . based on the method of specimen collection , the needles are classified into aspiration type and biopsy type . aspiration needles are used to acquire specimens by aspirating tissues into the lumen of the outer sheath , while biopsy needles are used to cut specimens that are aspirated into the lumen of the needle . here , we report a case of gastric gist diagnosed with specimens obtained by eus - fna with a 25 g biopsy needle . a 56-year old woman underwent screening with upper gastrointestinal endoscopy ( gif - xrq260 ; olympus , tokyo , japan ) . contrast - enhanced computed tomography ( somatom emotion 16 ; siemens , munich , germany ) was performed for further analysis of the submucosal tumor ( fig . the low - density area was covered with a thin layer of gastric mucosa . for further investigation of the submucosal tumor , eus was performed ( gf - uct260 ; olympus ) . a hypoechoic lesion with a clear margin color doppler image showed a pulsating vascular signal extending into the center of the low - echo lesion from the periphery . eus - fna was performed for pathological evaluation of the submucosal tumor with a 25 g biopsy needle ( echo - hd-25c , cook medical inc . , a fragment of tissue was obtained from the clot and was stained using hematoxylin and eosin ( fig . there was a possibility that these spindle - shaped cells were gastrointestinal stromal tumor or leiomyoma cells . no signal was observed on immunostaining with antit - s100 , a marker of nerve cells ( fig . 3b ) or anti- smooth muscle actin , a marker of smooth muscle cells ( fig . eus - fna is an established and relatively safe technique , with virtually no complications . there are two types of needles available for eus - fna : aspiration type and biopsy type . one major limitation of eus - fna with the aspiration needle is that the acquired specimens are sometimes fragmented and not suitable for pathological analysis such as immunostaining . the 19 g biopsy needle is used to cut specimens that are aspirated into the lumen of the needle . this 19 g biopsy needle in eus - fna can obtain enough specimens for pathological analysis compared to a 22 g aspiration needle . potential complications associated with the used of the 19 g biopsy needle are bleeding and perforation . they concluded that the 22 g biopsy needle is more suitable to obtain enough specimens for pathological analysis . in our case , the 25 g biopsy needle was used . our data suggested that the 25 g needle was adequate to obtain specimens for pathological analysis . the 22 g or 25 g aspiration needle is used for gastric smts less than 10 mm in size . it was expected that the 25 g biopsy needle would be useful to obtain specimens suitable for pathological analysis , with fewer complications even from a small gastric smt . in conclusion , it was found that a 25 g biopsy needle was suitable for eus - fna of gastric gist . it was not assigned as a clinical trial , but was considered a part of daily clinical practice . written informed consent for this report was obtained from the patient . patient records were anonymously and retrospectively analyzed . written informed consent was obtained for upper gastrointestinal endoscopy , contrast - enhanced computed tomography , eus , and eus - fna .
endoscopic ultrasound - guided fine needle aspiration ( eus - fna ) is performed to obtain specimens for pathological analysis . for this procedure , 19-gauge ( 19 g ) , 
 22-guage ( 22 g ) , and 25-guage ( 25 g ) needles are available . 
 the needles are classified into aspiration type and biopsy type . 
 a 56-year - old woman underwent upper gastrointestinal endoscopy that showed a 38-mm - diameter submucosal tumor . 
 the elevated lesion was diagnosed as a submucosal tumor of the stomach . 
 contrast - enhanced computed tomography showed a low - density area on the luminal surface of the gastric wall , which was covered with a thin layer of gastric mucosa . 
 eus showed a hypoechoic lesion in the submucosal layer . 
 color doppler image showed a pulsating vascular signal extending into the center of the hypoechoic lesion from the periphery . 
 eus - fna was performed with a 25 g biopsy needle . the specimen tissue consisted of spindle - shaped cells . 
 the cells were positive for cd117 and cd34 . 
 the submucosal tumor was diagnosed as a gastrointestinal stromal tumor .