A scary looking polyp

August 06, 2015 By: Bjorn Rembacken

A scary looking polyp

What would you do if you found this polyp in the high rectum of an elderly patient?

These four photographs show a polyp that was found in the high rectum of an elderly patient.

 

WHAT WOULD YOU DO NEXT?

a)     Take a full set of samples and wait for histology findings

b)     Take samples and request an endoscopic ultrasound (EUS)

c)     Take samples and request staging X-rays

d)     Resect the polyp endoscopically

e)     Refer the polyp for transanal resection

Discussion

Clearly, this polyp is likely to be malignant. However, for some reason I decided to attempt a ‘test lift’ injection of colloid/adrenaline/indigo carmine dye into the submucosa. To my surprise the polyp lifted without any sign of tethering (bottom-right image) and I was able to remove it as a single fragment. The polyp turned out to be a tubular adenoma with a small spot of cancer in the centre.

Haggitt staging is the classic histological staging of the extent of invasion of cancers arising within pedunculated polyps.1 

  • Level 0 = Carcinoma in situ or intramucosal carcinoma (Haggitt level 0 lesions are not recognised in the UK because British histopathologists want to see malignant cells invading below the muscularis mucosa before they label a polyp as malignant).
  • Level 1 = Carcinoma invading through the muscularis mucosa into the submucosa, but limited to the head of the polyp.
  • Level 2 = Carcinoma invading the level of the neck of the adenoma.
  • Level 3 = Carcinoma invading any part of the stalk.
  • Level 4 = Carcinoma invading into the submucosa of the bowel wall below the stalk of the polyp, but above the muscularis propria.

Histopathologists may, however, be reluctant to apply the Haggitt classification because they can often have difficulty distinguishing the important boundaries between the head and neck and the neck and stalk of the polyp. These boundaries are arbitrary and subject to interobserver variability. Furthermore, if the stalk has been cut just below the head of the polyp, it will be impossible to diagnose a Haggitt level 4 lesion.

Naturally, all cancers staged as Haggitt level 4 are referred for further therapy. However, in Haggitt’s original publication, lymph-node metastases were also found in 6 out of 24 patients with Haggitt level 3 lesions.1

For flat lesions, cancers are staged using the Kikuchi classification.2 The risk of lymph-node metastasis for Kikuchi levels sm1, sm2 and sm3 is 2%, 8% and 23%, respectively.3 Unfortunately, it is difficult to use the Kikuchi system as there is normally no muscularis propria within the endoscopic resection fragment (unless you have cut too deep and perforated the colon of course).

In this particular case, the endoscopist would have noted that there is no discernable crypt pattern in the centre of the lesion. The endoscopist may well have made an endoscopic diagnosis of a ‘massively invasive cancer’ (i.e. cancer invading deeper than 1mm below the muscularis mucosa) and not have attempted resection. However, the detection of a suspicious crypt pattern (severely distorted crypt pattern or no pattern at all) has less relevance in pedunculated polyps, in which lesions can still be endoscopically resectable even if the tip of the lesion harbours a cancer.

This polyp is also a good example of the practical difficulties our histopathologists may encounter when attempting to apply the Haggitt and the Kikuchi staging systems. Is this lesion pedunculated or sessile? In this case it is neither, and neither the Haggitt nor the Kikuchi staging system applies! Because of such difficulties, Japanese histopathologists instead rely on simply measuring the depth of invasion beyond the muscularis mucosa.4 Lesions invading less than 0.5 mm (i.e. <500 µm), are regarded as Kikuchi level 1 (sm 1 invasion), 500–1,000 µm as level 2 invasion and >1,000 µm as level 3 invasion.

In this case, the depth of invasion was <500 µm and the deep margin was clear by several mm. In addition, no adverse features were found within the polyp (i.e. it was a well-differentiated cancer without any lymphovascular invasion). For these reasons, we decided not to offer the patient any further treatment beyond polypectomy.

 

References

  1. Haggitt RC, Glotzbach RE, Soffer EE, et al. Prognostic factors in colorectal carcinomas arising in adenomas: implications for lesions removed by endoscopic polypectomy. Gastroenterology 1985; 89: 328–336. 
  2. Kikuchi R, Takano M, Takagi K, et al. Management of early invasive colorectal cancer. Risk of recurrence and clinical guidelines. Dis Col Rect 1995; 38: 1286–1295. 
  3. Nascimbeni R, Burgart LJ, Nivatvongs S, et al. Risk of lymph node metastasis in T1 carcinoma of the colon and rectum. Dis Col Rect 2002; 45: 200–206.
  4. Ueno H, Mochizuki H, Hashiguchi Y, et al. Risk factors for an adverse outcome in early invasive colorectal carcinoma. Gastroenterology 2004; 127: 385–394. 

Answer

Correct answer: D.

 

 

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

 

Comments

Bjorn Rembacken, November 30, 2016 22:21
At the bottom right image you can see that the polyp actually lifts very well with a submucosal injection of blue indigocarmine dye and colloid. A 'test-lift' is always worth while in cases of suspicious polyps. If the suspicious looking lesion doesn't lift, you are probably dealing with a malignancy. In this case the polyp turned out to be benign (TA+HGD) ! You could have knocked me over with a feather !
Nazish, October 26, 2015 10:44
B
Akiko Ono, October 26, 2015 09:28
How very old is the patient?
I wouldn't care about pit pattern in an ulcerated polypoid lesion..Initially I would take samples, stage (specially EUS) and wait for results. Very interesting polyp though. Thank you for showing the images.
Can, August 22, 2015 08:14
I would have take biopsies and stage this lesion. Did you get any staging investigations at all ? Tattooed, as our insist on tatooing lesions in the rectum.

Good lift though!
Aida Jawhari, August 10, 2015 22:16
There are 2 polyps. The larger distal polyp has type IV pits. It is likely to be an invasive lesion. I would take biopsies and arrange staging investigations.

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