gastrointestinal stromal tumors ( gist ) are rare mesenchymal and typically subepithelial neoplasms that account for approximately 1  % of the gastrointestinal tumors 1 . gists most commonly originate from the interstitial cells of cajal ( icc ) in the fourth layer of the gastrointestinal tract wall ( muscularis propria ) . diagnosis is confirmed by expression of positive immunohistochemical staining for cd117 ( kit receptor tyrosine kinase , c - kit protein ) , which is found in 95  % of cases . the overall gist incidence is estimated to range between 10 to 20 cases per million among the adult population 1 . gists in childhood either occur sporadically or in the context of hereditary syndromes like neurofibromatosis type 1 ( nf1 ) or carney - stratakis syndrome . nevertheless , the occurrence of sporadic duodenal gists in children and young adults is exceedingly low . a literature search revealed that only 2 cases of duodenal gists in children have been reported 3 
 4 . here we report on the case of a 19-year old female patient who was admitted in hemorrhagic shock due to suspected gastrointestinal bleeding . a 19-year - old otherwise healthy female tourist was admitted to a secondary care hospital after fainting while skiing due to suspected gross blood loss with an initial hemoglobin level of 60 after volume resuscitation including red blood cell ( rbc ) transfusions , a tumorous mass with a central bleeding ulceration ( bull s eye appearance , fig . the submucosal tumor bulging into the duodenal lumen was found in immediate proximity to the major duodenal papilla ( fig .  2 ) . blood oozing was noted and primary hemostasis was accomplished by injection of saline - diluted epinephrine and the application of 2 instinct endoscopic hemoclips . non - contrast - enhanced computed tomography failed to locate the primary tumor and did not reveal any distant metastasis . after overnight observation , the patient was transferred to our tertiary care hospital for further diagnostic work - up . duodenal tumorous mass with central vessel bulging into the lumen ( bull s eye appearance ) . 
 bleeding duodenal mass adjacent to the major duodenal papilla ( black arrow ) . upon arrival at our institution , the neoplasm with a central bleeding vessel arose from the muscularis propria ( fourth wall layer ) and measured 25    15  mm ( fig .  3 and fig . our initial differential diagnosis based on clinical presentation and endosonographic imaging consisted of gastric stroma tumor ( gist ) , neuroendocrine tumor ( net ) , gangliocytic paraganglioma 5 , leiomyoma 6 and solid pseudo - papillary tumor of the pancreas 7 . in addition to endosonography - guided fine - needle aspiration , regular biopsies were harvested and an on - site cytologist ensured attainment of diagnostic tissue . recurrent tumor bleeding after tissue harvesting was then stopped by application of hemospray . after observing a recurrent decrease in hemoglobin levels during the following night given the lack of further endoscopic hemostasis options , transarterial coil embolization of the tumor - supplying anterior pancreaticoduodenal arcade was performed ( fig . intermittent bleeding was confirmed by duodenoscopy and no permanent hemostasis was achieved by gold probe coagulation . the bleeding was finally halted by coil embolization of the inferior pancreaticoduodenal artery via the superior mesenteric artery and the origin of the posterior arcade via the gastroduodenal artery . the diagnosis of a gist was ultimately established by positive staining for cd117 ( ckit ) , cd34 and dog-1 and negative staining for sma und s100 panck b. 
 hypervascular tumor ( black arrow ) of the duodenum predominantly supplied by the anterior pancreatoduodenal arcade . after no further bleeding was detected over the course of the next 48 hours , the patient was transferred to a center in her home country for further treatment . after an initial trial of tumor downsizing with imatinib , the medication had to be discontinued due to severe adverse events including vomiting , diarrhea , fatigue and severe bone marrow suppression requiring multiple transfusions . the final histology report of the in toto resected gist ( positive staining for cd117 , cd34 and dog1 ; negativity for desmin , s11 and cd31 ) displayed 3 mitoses/50 hpf . these findings correspond to a low risk ( 8.3  % ) for progressive disease 8 . we here report the third case in literature of a duodenal gist in a patient younger than age 20 . the initial presentation of the tumor in our teenage patient was a life - threatening arterial tumor bleeding with consecutive hemorrhagic shock . even though pediatric gists frequently present with gastrointestinal bleeding 9 , the highly delicate duodenal location in immediate proximity to the major duodenal papilla rendered the hemostasis very challenging in our case . in contrast to our case , the vast majority of previously reported bleeding pediatric gists were located in the stomach and therefore potentially more easily accessible for endoscopic or surgical hemostasis 10 
 11 .   given the challenging tumor location adjacent to the papilla of vater , we sought to establish a histopathologic diagnosis before performing an extensive surgical procedure such as pancreaticoduodenectomy ( whipple s procedure ) on our patient . while awaiting definite histopathologic diagnosis including immunohistological staining , all conventional endoscopic hemostasis procedures ( including epinephrine injection , classical and instinct endoscopic hemoclip application , argon plasma coagulation , gold probe coagulation and application of hemospray ) failed to adequately control the life - threatening tumor bleeding . fearing a complete closure of the common biliary and the pancreatic duct , otsc application on the juxtapapillary lesion ultimately , only a second transarterial coil embolization stopped the intermittent arterial gist bleeding permanently and allowed stabilization of the patient for repatriation to her home country for definite resection ( bridge to resection ) . although some authors claim that pediatric gists are a different entity with variable local and systemic tumor behavior than adult gists 9 , complete endoscopic or surgical resections ( r0 ) also remain the cornerstone for pediatric gist treatment . depending on tumor size and mitotic rate , risk of recurrence and metastasis rate can be estimated and an individual treatment plan needs to be created , including optional adjuvant treatment with the tyrosine receptor inhibitor imatinib and appropriate surveillance frequency 1 . despite the very rare gist occurrence in children and young adults , it should be included in the differential diagnosis for gastrointestinal blood loss , iron deficiency anemia and unexplainable gastrointestinal pain . given the fairly high incidence of metastasis ( approx . 50  % ) and the elevated recurrence rate , early diagnosis of gist is even more crucial in young patients with a potentially long life expectancy 12 .
duodenal gastrointestinal stromal tumors ( gist ) are per se infrequent and are 
 exceptional in children or young adults . 
 so far , only 2 cases of pediatric 
 duodenal gists have been published . here 
 we report on the case of a 19-year - old 
 female patient who was admitted in hemorrhagic shock due to arterial bleeding of 
 a duodenal gist located in immediate proximity to the major duodenal papilla . 
 after several attempts of endoscopic hemostasis failed , the tumor bleeding was 
 controlled with a second coil embolization of the pancreaticoduodenal 
 arcades .