somatostatinoma was first reported in 1997 by larsson et al.1 since then , only a handful of cases have been reported worldwide because of the extremely low incidence of this tumor , estimated to be 1 in 4 million.2 women were found to have higher incidence than men.3 most of the cases were symptomatic , with some clinical features of inhibitory symptoms such as diabetes mellitus - like symptoms , steatorrhea , cholelithiaisis , and chronic diarrhea . asymptomatic somatostatinoma accounted for approximately 10% of reported cases.4 the most common locations for tumors were the duodenum and pancreas.5 this tumor was malignant in 60% to 70% of cases with tumor size usually less than 5 cm . an association between somatostatinoma and some familial neuroendocrine disorders such as neurofibromatosis and von hippel - lindau syndrome was reported in approximately 7% of cases . adjuvant chemotherapy was not advocated after surgery . despite slow disease progression , 5-year survival after incomplete resection of the tumor was reported to be 60% to 100%.6 we report a case of somatostatinoma with an unusual location and rare manifestation . a 49-year - old woman with a history of type 2 diabetes mellitus for a few years presented with chronic abdominal discomfort and nausea for 1 year . three months earlier , she complained of severe abdominal pain , significant weight loss , and chronic intermittent watery diarrhea . abdominal sonography showed a large epigastric mass , 1016 cm in size , with multiple hyperechoic nodules at both lobes of the liver and peripancreatic lymphadenopathy , suspected to be metastatic spread to the lymph nodes . the patient was scheduled for a computed tomography ( ct ) scan of the upper abdomen . while she was waiting at the radiology unit , she developed hematemesis and was referred to the internal medicine department for further treatment endoscopy showed a large mass , approximately 15 cm in diameter , in the upper gastric body . the mass extended down to the antrum and duodenal bulb with blood oozing ( fig . , endoscopic ultrasonography was performed , and a large well - defined isoechoic gastric subepithelial mass more than 138 cm in diameter was detected ( fig . multiple intra - abdominal and peripancreatic lymphadenopathy were detected , and the lesions varied in size from 8 to 25 mm . fine needle aspiration was performed on the mass , and the cytology results led to a suspicion of malignancy . the ct scan showed a large soft tissue mass , with multiple liver metastases and intra - abdominal lymphadenopathy ( fig . gross pathology showed tumor involvement of the posterior wall of the stomach , with the tumor forming a large intramural multinodular mass ( fig . multiple well - circumscribed masses were detected at the pancreatic head and body and at the first part of the duodenum . histopathology showed that the tumor was arranged in solid nests or in an acinar pattern infiltrating from muscularis propria of the stomach through the mucosa and extending to the duodenum . their nuclei were monotonous and bland , with salt and pepper nuclear chromatin , a typical characteristic of neuroendocrine tumors including positivity for typical characteristic of psammoma bodies ( fig . however , she developed acute jejunal obstruction 2 weeks later due to intussusception from the jejunal leiomyoma and underwent gastrojejunostomy . this case of somatostatinoma involved a tumor , whose size was the largest ever reported . tumors in most of the reported cases were smaller than 5 cm . more than 85% were symptomatic and more than two - thirds were malignant.7 - 9 the most common locations of this tumor were the duodenum and pancreas . however , this patient 's gastric somatostatinoma was detected in a rare location . in the presented case , the patient only had chronic intermittent watery diarrhea , one of the clinical presentations of classic somatostatinoma syndrome , without any other symptoms . in many other reports , these classic somatostatinoma syndrome presentations were more common for pancreatic masses , whereas obstructive symptoms such as abdominal pain , nausea , and vomiting were more common for duodenal masses . interestingly , this patient presented with acute massive gastric haemorrhage , which was a rare manifestation of this tumor . duodenal and periampullary bleeding have been reported in very few cases worldwide as a clinical presentation.10 - 12 the bleeding was easily stopped with an adrenaline injection . surprisingly , the endosonographic study could not demonstrate any difference between this tumor and other subepithelial tumors such as gastrointestinal stromal tumor . in our previous study,13 it was very difficult to differentiate the etiology of large subepithelial tumors , especially those larger than 9 cm in diameter , using only endosonographic characteristics . therefore , a definite diagnosis must be based on cytology and histopathology with special immunohistochemical stains . no data supports the benefit of adjuvant chemotherapy for the treatment of metastatic somatostatinoma , although few small case series reported that the synthetic somatostatin analogue octreotide , at 0.5 mg subcutaneously per day , had some benefits , including reduced diarrhea and other somatostatinoma symptoms , and stabilised tumor growth . some studies on somatostatinoma reported no benefit from this treatment , which might be from a different subtype of somatostatin produced from the tumor.14,15 the overall 5-year survival for metastatic somatostatinoma was reported at approximately 40% , whereas that for small nonmetastatic lesions is 100%.15
a 49-year - old woman presented with chronic abdominal discomfort , significant weight loss , and chronic intermittent diarrhea . 
 she suddenly developed massive upper gastrointestinal bleeding and was referred for further treatment . 
 endoscopy indicated a large mass in the upper gastric body with antral and duodenal bulb involvement . 
 endosonography showed a large well - defined isoechoic gastric subepithelial mass with multiple intra - abdominal and peripancreatic lymphadenopathy , suspected to be malignant on the basis of fine needle aspiration cytology . 
 the tumor was surgically removed , and histopathology showed typical characteristics of a neuroendocrine tumor . 
 on the basis of immunohistochemical staining , somatostatinoma , a rare neuroendocrine tumor , was diagnosed . 
 gastrointestinal bleeding is a rare presentation and the stomach is an uncommon tumor location .