gastrointestinal stromal tumors ( gist ) represent less than 1% of all primary tumors of the gastrointestinal tract ( git ) and commonly affect patients in the middle and older age groups with equal gender distribution . . their sub mucosal location can produce local obstructive symptoms , particularly when arising in the esophagus or the small intestine . most gists usually present with vague upper abdominal pain , fullness or gastrointestinal ( gi ) bleeding . sometimes they are found incidentally during barium studies , endoscopy or abdominal scans performed for other reasons . a 40-year - old man presented with a history of rectal bleeding for two days , with a reported loss of more than 1 liter of fresh blood . despite intensive fluid management with whole blood and normal saline , colonoscopy was not attempted because of continuous bleeding . tc-99 m labeled red blood cell ( rbc ) scintigraphy [ figure 1 ] showed accumulation and movement of tracer in the mid - abdomen , corresponding to the region of the jejunal loops . a diagnosis of active gastro - intestinal bleed ( likely to be from the jejunum ) was made , and the patient taken up for exploratory laparotomy . a polypoidal exophytic mass about 4 cm in size was found in the jejunal wall , 40 cm from the duodeno - jejunal junction . the mass along with the adjoining jejunal loops was resected , followed by end - to - end anastomosis . gross examination of the specimen [ figure 2a and b ] showed a polypoidal mass ( measuring 3.2 cm in its largest dimension ) arising from the serosal aspect , producing a bulge in the central part of the mucosa , which was ulcerated and could be the possible source of bleeding . microscopic examination [ figure 2c ] showed a well - circumscribed tumor in the submucosa . the mass showed a spindle cell tumor arranged in long interlacing fascicles with characteristic perivascular arrangement of tumor cells . the tumor cells were moderately pleomorphic with mitotic rate of 2/50 high power field ( hpf ) . following surgery , the patient made a satisfactory recovery and was discharged on the seventh post - operative day . dynamic scintigraphy using tc-99 m labelled red blood cells showing accumulation and movement of tracer in the mid - abdomen ( arrows ) the resected specimen from the jejunum ( a and b ) a polypoidal mass arising from the serosal aspect , with an ulcerated bulge in the central part of the mucosa ( c ) microscopic examination shows a spindle cell tumor arranged in long interlacing fascicles with perivascular arrangement of tumor cells ( d ) immunoperoxidase staining showing cd-117 positivity gists are derived from cajal cells or their precursors and most commonly occur after the age of 50 years in the stomach ( 60% ) , jejunum and ileum ( 30% ) , duodenum ( 4 - 5% ) , rectum ( 4% ) , colon and appendix ( 1 - 2% ) , and esophagus ( < 1% ) , rarely as apparent primary extra - gastrointestinal tumors in the vicinity of the stomach or intestines . the role of labeled rbc scintigraphy in acute gastro - intestinal bleeding is well - established and its application in rare cases has also been reported . however , few authors have discussed the role of tc-99 m rbc scintigraphy in discovering a bleeding gist . surgery is the primary treatment of choice for patients with localized or potentially resectable gist lesions and is recommended if bleeding is present . the scottish intercollegiate guidelines network ( sign ) recommends that nuclear scintigraphy should be considered to assist in localization of bleeding in patients with significant recent lower gi hemorrhage . although colonoscopy is the initial diagnostic modality of choice to localize the bleeding site for patients presenting with acute severe hematochezia , it is difficult when patients present with profuse bleeding . in these situations arteriography or labeled rbc scintigraphy is warranted . as a non - invasive investigation that requires no specific patient preparation , there is also no need of any iodinated contrast that may cause contrast - nephropathy in acutely ill - patients . since the risk of malignancy was low in our patient , he has been kept under follow - up with no adjuvant treatment . this report highlights the advantage of this non - invasive investigation in hemodynamically unstable patients by detecting and localizing the site of an active gi bleed .
the role of 99m - technetium labeled red blood cell ( rbc ) scintigraphy in acute gastro - intestinal bleed is well - established . 
 the authors report a case of a bleeding gastrointestinal stromal tumor ( gist ) incidentally discovered on tc-99 m rbc scintigraphy .