Confusion over a rectal biopsy sample

November 19, 2015 By: Bjorn Rembacken

Figure 1 | The nodule found in the rectum of the case patient.

Figure 2 | H&E stain of a biopsy sample taken from the nodule in the rectum of the case patient.

Confusion over a rectal biopsy sample

How would you manage this nodule?    

The nodule shown in the photograph was found in the rectum of an elderly, asymptomatic patient undergoing a gastroscopy and colonoscopy because of mild iron-deficiency anaemia (figure 1). Biopsy samples were taken from the nodule and the H&E stain is shown (figure 2).


a)     Ignore the polyp

b)     Sample it again

c)     Remove it by endoscopic mucosal resection

d)     Remove it by endoscopic submucosal dissection

e)     Remove it surgically



There was some confusion over the biopsy samples taken from this lesion because the H&E stain shows gastric mucosa. Indeed, there was a suggestion that biopsy samples taken from the stomach and rectum had been mixed up; however, this was not the case. In fact, the patient has a patch of ectopic gastric mucosa in the rectum!

Endoscopists are used to finding ectopic gastric mucosa in the high oesophagus; although this is the first time that I have seen ectopic gastric mucosa in the rectum, the condition was first described in 1939.1 Most case reports of ectopic gastric mucosa in the rectum have been in children presenting with rectal bleeding. Marines et al. reviewed the first 12 published cases in 1988 and concluded that in all cases the ectopic tissue was located within 10 cm of the anus.2 There have also been case series of gastric mucosa arising within the anus.3

It has been proposed that the reason for heterotopic gastric mucosa is abnormal differentiation of the endoderm.4 However, the finding of more than one type of gastric mucosa (cardiac, fundic, antral, pyloric or associated with heterotopic pancreatic tissue) suggests that the condition is due to a developmental ‘accident’. Another indication that the condition is caused by neural-crest-derived cells going astray, is that the condition is commonly associated with a rectal duplication cysts.5

Naturally, the condition will only require treatment if there is ulceration when either acid-reducing therapy6,7 or surgery is indicated. Gastric cancer arising from heterotopic gastric mucosa in the oesophagus is well described, but I have not found a single case report of gastric cancer arising in the rectum.



  1. Ewell GH and Jackson RH. Aberrant gastric mucosa in the rectum with ulceration and hemorrhage. Wisc Med J 1939; 38: 641–643.
  2. Menchaca Marines MCM, Posselt HG and Waag KL. Ectopic gastric mucosa in rectum; A rare cause of rectal bleeding in children. J Pediatr Gastroenterol Nutr 1988; 7: 293–297. 
  3. Steele SR, Mullenix PS, Martin MJ, et al. Heterotopic gastric mucosa of the anus: a case report and review of the literature. Am Surg 2004; 70: 715–719. 
  4. Wolff M. Heterotopic gastric epithelium in the rectum. A report of three new cases with a review of 87 cases of gastric heterotopia in the alimentary canal. Am J Clin Pathol 1971; 55: 604–616.
  5. Holcomb GW, Gheissari A, O'Neill JA Jr, et al. Surgical management of alimentary tract duplications. Ann Surg 1989; 209: 167–174. 
  6. Castellanos D, Menchen P, Lopez de la Riva M, et al. Heterotopic gastric mucosa in the rectum. Endoscopy 1984; 16: 197–199. 
  7. Pistoia MA, Guadagni S, Tuscano D, et al. Ulcerated ectopic gastric mucosa of the rectum. Gastroint Endosc 1987; 33: 41–43. 


Correct answer: a.

About the author

Bjorn Rembacken is at Leeds Teaching Hospitals NHS Trust, Leeds, UK. He was born in Sweden and qualified from Leicester University in 1987. He undertook his postgraduate education in Leicester and in Leeds. His MD was dedicated to inflammatory bowel disease. Dr Rembacken was appointed Consultant Gastroenterologist, Honorary Lecturer at Leeds University and Endoscopy Training Lead in 2005. Follow Bjorn on Twitter @Bjorn_Rembacken



Bjorn, December 04, 2015 13:25
No cigar as yet! It's not a GIST and its not anything to do with rectal prolapse. Way more weird than that !
Joana, November 26, 2015 00:22
Histologically it seems an inflammatory cloagenic polyp, mostly associated with a prolapse, that should be corrected. There is a low risk of malignancy but excision of the lesion is a valid option, Considering this is the case of an elderly asymptomatic patient the option a) would be the one I take.
Irina Korytko, November 25, 2015 16:22
Can it be a fistula? then E
Evgeniya Peganova, November 25, 2015 07:28
Evgeniya Peganova, November 25, 2015 07:28
Mosab Samamra, November 24, 2015 18:27
Mostly this GIST ,We have to do TRUS .after that can descide emr esd or not .
Fabián Eduardo, November 23, 2015 17:59
An Rectal EUS first?
mohamed badr, November 23, 2015 11:38
Kamel Mir, November 20, 2015 22:58
Sampsa Pikkarainen, November 20, 2015 22:51

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