An interesting ileal finding

October 26, 2015 By: Nick Burr

Figure 1 | A lesion detected in the terminal ileum of the 50-year-old case patient during colonoscopy, visualised by white-light imaging (WLI) and narrow-band imaging (NBI).

Figure 2 | A CT scan demonstrating the presence of a nodular mass in the terminal ileum of the case patient.

Figure 3 | A CT scan demonstrating enhancing mesenteric nodal disease in the case patient.

Nick Burr BSc, MBBS, MRCP is a Clinical Academic Fellow in Gastroenterology at Leeds Teaching Hospitals NHS Trust, UK.

An interesting ileal finding

What are the treatment options for this lesion discovered during colonoscopy?

A 50-year-old woman is undergoing a colonoscopy because of loose stool. When the tip of the endoscope enters the terminal ileum, the lesion in the photograph is found. The patient asks you if any treatment will be necessary.

 

WHAT DO YOU TELL THE PATIENT?

a)     The lesion is likely to be a lipoma and can probably be ignored

b)     The lesion is likely to be adenomatous and should be removed by endoscopic mucosal resection (EMR)

c)     The lesion is likely to be a neuroendocrine tumour (NET) and should be removed surgically

d)     The lesion is likely to be a gastrointestinal stromal tumour (GIST), requiring annual surveillance

e)     None of the above 

Discussion

This is an odd-looking polyp that has a smooth head with some linear vessels extending from its base towards its apex. There appears to be a submucosal component to the polyp as demonstrated by the biopsy forceps in the white-light image (figure 1 [WLI]). The endoscopic diagnosis was of a neuroendocrine tumour (NET), so the lesion was sampled and an abdominal CT requested.  The CT scan demonstrated a nodular mass in the terminal ileum (figure 2) and enhancing mesenteric nodal disease (figure 3).

At endoscopy, NETs (previously known as carcinoids) are firm, submucosal nodules with or without an umbilicus.  The finding of thicker than usual vessels extending from the base of the polyp towards the apex is a common (but not invariable) pointer to the diagnosis.

NETs are neoplasms of the neuroendocrine cells, which are cells widely distributed throughout the body. Although the small intestine is a common site for NETs (16–29% of lesions develop at this site), the absolute incidence is low, approximately 0.5 per 100,000 per year.1 Well-differentiated lesions are usually indolent and slow growing with a prolonged natural history. By contrast, poorly differentiated lesions have a rapidly progressive clinical course and poor prognosis. The average 5-year survival rate for patients with mid-gut NETs is improving and is currently around 75%.2

Once an NET is suspected, the case should be discussed at a dedicated cancer meeting. The patient should have baseline investigations including measurement of chromogranin A (CgA) and urinary 5-hydroxyindoleacetic acid (5-HIAA) concentrations. Care needs to be taken when interpreting CgA measurements as a raised CgA concentration can have several other causes, such as use of a proton pump inhibitor (PPI), atrophic gastritis, chronic renal failure, liver cirrhosis, congestive heart disease and other secretory tumours (e.g. hepatocellular carcinoma, thyroid cancer). Most NETs (between 50–75%) are nonfunctional and do not secrete hormones such as serotonin, insulin or gastrin.

Naturally, histological analysis is essential. The World Health Organization (WHO) classifies all gastroenteropancreatic NETs into low grade (Ki-67 at 2%, mitotic count <2/HPF), intermediate grade (Ki-67 3–20%, mitotic count 2–20/10 HPF), and high grade (Ki-67 >20%, mitotic count >20%).3 The prognosis is worse for patients who have NETs with a higher WHO grading and in those who have metastatic disease. Interestingly, the presence of hormone secretion is not known to influence prognosis.

In view of their high malignant potential, all ileal NETs, even those that are small, should be considered for curative surgery. Indeed, ileal NETs should not be resected endoscopically. In the 35,618 NETs registered in the Surveillance, Epidemiology and End Results (SEER) Programme, local nodal involvement was found in 41% of cases and distant metastases in 30%.1  In up to 40% of cases multiple tumours were found. Owing to the known increased risk of cholelithiasis, some centres advocate prophylactic cholecystectomy at the time of surgical resection.

Following surgical resection, the European guidelines suggest post-operative surveillance every 6–12 months, via the comparison of CgA and urinary 5-HIAA levels with baseline measurements, because NETs have a relatively high risk of recurrence.4 For patients with unresectable disease, options to control tumour growth and symptoms related to tumour bulk or hormonal hypersecretion include somatostatin analogues, nonsurgical liver-directed therapy, and systemic chemotherapy. Palliative surgery should be considered for patients who are at risk of bowel obstruction.5

Guidelines for the diagnosis and treatment of gastroenteropancreatic NET have been published by the European Neuroendocrine Tumour Society (ENETS),4 the National Comprehensive Cancer Network (NCCN) and the North American Neuroendocrine Tumour Society (NANETS).6

 

References 

  1. Yao JC, Hassan M, Phan A, et al. One hundred years after “carcinoid”: epidemiology of and prognostic factors for neuroendocrine tumors in 35,825 cases in the United States. J Clin Oncol 2008; 26: 3063–3072. 
  2. Strosberg J, Gardner N and Kvols L. Survival and prognostic factor analysis of 146 metastatic neuroendocrine tumors of the mid-gut. Neuroendocrinol 2009; 89: 471–476. 
  3. Klöppel G, Perren A, Heitz PU. The gastroenteropancreatic neuroendocrine cell system and its tumors: The WHO classification. Ann NY Acad Sci 2004; 1014: 13–27. 
  4. Pape UF, Perren A, Niederle B, et al. ENETS consensus guidelines for the management of patients with neuroendocrine neoplasms from the jejuno-ileum and the appendix including goblet cell carcinomas. Neuroendocrinology 2012; 95: 135–156. 
  5. Pavel M, Baudin E, Couvelard A, et al. ENETS consensus guidelines for the management of patients with liver and other distant metastases from neuroendocrine neoplasms of foregut, midgut, hindgut, and unknown primary. Neuroendocrinology 2012; 95: 157–176. 
  6. Boudreaux JP, Klimstra DS, Hassan MM, et al. The NANETS consensus guideline for the diagnosis andmanagement of neuroendocrine tumorswell-differentiated neuroendocrine tumors of the jejunum, ileum, appendix, and cecum. Pancreas 2010; 39: 753–766.  

Answer

Correct answer: c.

 

 

About the author

Nick Burr is a Clinical Research Fellow in Leeds, where he is undertaking an MD investigating the long-term outcomes in patients with inflammatory bowel disease by using primary care data. His other interests are gastrointestinal haemorrhage and training in therapeutic endoscopy.

   

 

Comments

Hazeez Albiladi, October 26, 2015 13:07
E
Jens K, October 26, 2015 12:49
In NBI it looks loke an adenoma but in CT-Image shows an unusual long segment of a thick wall. So a NET is the probably right answer.
PANTELIS, October 26, 2015 12:20
Does not look like a lipoma,adenomas are rare in terminal ileum,gist does not cause nodal disease..but always wait for the histology
Tomica, October 26, 2015 11:36
Looks like a GIST-wait a bit for histology and to discuss the trestment options
Frida Yosilevich, October 26, 2015 11:36
Net and need surgical remove
Aiste Puriene, October 26, 2015 11:02
E, waitting for histology
Annikka Polster, October 26, 2015 11:00
E, need more information
Samer Khalife, October 26, 2015 10:55
C after pathology result
Sean Michael Phillip Bennet, October 26, 2015 10:46
I'd answer E. I'd also like to add that althouh UEGweek ha only just offcally begun I'm looking forward to a very engaging conference!
Nazish, October 26, 2015 10:43
C

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