the overall annual incidence of intussusception in adults in the general population has been reported to be as low as 2 cases/1 000 000 persons ; adults account for ~5% of confirmed intussusceptions . as high as 90% of cases of adult intussusception
are due to a pathological process , with neoplasms accounting for ~60% of identifiable leadpoints .
one 6-year prospective study encompassing screening of 380 999 computed tomography ( ct ) scan reports that were read as intussusception , 0.04% of cases were in adults . in adults ,
surgery is typically performed owing to the likelihood that a neoplastic or otherwise chronic pathology is the cause of the intussusception .
indications to take any case to the operating room include large caliber of telescoped bowel , long length of telescoped portion , identifiable lead point and evidence of obstruction [ 24 ] .
the former indications owe to the increased likelihood of malignancy requiring surgical exploration and incision , and bowel wall and mesenteric ischemia in the setting of large intussusceptions .
a 61-year - old gentleman presented with a 3-day history of right - greater - than - left lower quadrant abdominal pain , distention , anorexia and one episode of emesis
. the patient also reported only consuming liquids for 57 days prior to presentation as solid foods caused significant discomfort .
three weeks prior , colonoscopic evaluation of his cramping was aborted at 20 cm due to an impassable sigmoid stricture . several hyperplastic polyps and one tubular adenoma
his abdomen was distended and tympanic , with tenderness and fullness appreciated in the right lower quadrant .
1 ) demonstrated small bowel obstruction due to an ileocolic intussusception , from the ileocecal valve to the splenic flexure , and collapsed distal colon .
figure 1:top left : origin ( arrow ) of invagination in the right lower quadrant .
the telescoped bowel contained terminal ileum , cecum , appendix and the entire ascending colon ( fig .
a 4.5 cm  5 cm mass was identified at the lead point , the ileocecal valve .
resection included the right hemi - colon , cecum , appendix and 15 cm of terminal ileum .
a diverting ileostomy was created as well as a mucus fistula for post - operative antegrade colonoscopic evaluation of the remaining colon . 

figure 2:left : stills from intraoperative video recording demonstrating the reduction of the intussusception in order to explore the lead point .
right : ischemic terminal ileum ( arrow ) and palpation of the lead point at the ileocecal valve . left : stills from intraoperative video recording demonstrating the reduction of the intussusception in order to explore the lead point .
right : ischemic terminal ileum ( arrow ) and palpation of the lead point at the ileocecal valve .
additional tubulovillous adenomas , tubular adenomas and hyperplastic polyps were identified throughout the excised portion of bowel .
figure 3:low - power ( left ) and high - power ( right ) views of lead point tumor demonstrates > 50% of the tumor composed of pools of mucin ( solid arrow ) , invasive tumor cells ( dotted arrow ) with hyperchromatic chromatin , crowded nuclei , surrounded by pools of mucin [ 57 ] .
low - power ( left ) and high - power ( right ) views of lead point tumor demonstrates > 50% of the tumor composed of pools of mucin ( solid arrow ) , invasive tumor cells ( dotted arrow ) with hyperchromatic chromatin , crowded nuclei , surrounded by pools of mucin [ 57 ] .
this patient 's presentation is exceptionally unique for both the size and cause of intussusception . to our knowledge ,
the few cases we found were always in the setting of malignancy , the patients presented with a similar chronologic progression with escalation of symptoms including liquid - only diets shortly before presentation .
additionally , the very large intussusceptions were always found in the setting of malignancy [ 1012 ] .
it seems that a favorable ( mobile ) anatomy with an indolent process is a common thread amongst these rare cases . further compounding the uniqueness of this case is the lead point tumor 's location and histology , along with the presence of additional terminal ileum and colonic polyps .
the annual incidence in the united states of small bowel adenocarcinoma from 1973 - -2005 is 6.8 cases per 1,000,000 person years , as calculated by surveillance epidemiology and results ( seer ) program .
additionally , ileocecal adenocarcinoma of any type is sparsely described outside of a few case reports [ 8 , 9 , 1315 ] .
mucinous adenocarcinoma tends to be a locally aggressive tumor , and metastasizes by redistribution phenomenon rather than vascular or lymphatic invasion .
presently , we have no unifying diagnosis to correlate the multiple lesions found throughout the telescoped bowel and distal 20 cm of colon and rectum .
however , it is currently estimated that up to 40% of patients with extensive polyps and a positive family history are ruled out for hnpcc by genetic testing for mismatch repair and msi , as was the case for this patient .
nevertheless , the unique presentation of this patient allowed for expeditious removal of a classically aggressive tumor , in what appears to be the first reported case of a long - tract intussusception secondary to a mucinous adenocarcinoma of the ileocecal valve .
 abstractintussusception in adults lacks specific symptoms and is often diagnosed emergently when they present with obstruction . though intussusception certainly varies in size and location , the increased likelihood of ischemia or obstruction make large intussusceptions very rare in the literature . 
 a patient admitted to our facility for small bowel obstruction was found to have extensive intussusception from the right lower quadrant to the splenic flexure , where a lead point was identified . 
 histopathology revealed multiple satellite lesions surrounding the lead point tumor , which was found to be invasive mucinous adenocarcinoma of the ileocecal valve . 
 while malignancy is found in 60% of lead point identifiable adult intussusceptions , a malignancy is always found in the case of an exceptionally large intussusception . 