Two pretty polyps !

Two gastric polyps (labelled A & B) were both removed from the stomach of a 60 year old woman who complained of indigestion. 
WHAT IS THE LIKELY DIAGNOSIS?

■ Both are hyperplastic

But the look different to each other!

■ NET + HP polyp

Well done ! And presumably you know which is which?

■ Both are NET's

But they look different!

■ HP + Adenoma

How about those fine vessels seen in the second image?

■ Both are adenomatous

But they look different!

explanation

You can see the thin vessels crawling up the side of polyp A. This appearance is typical of a gastric NET. Polyp B has a more villous surface with a few white spots - all typical of a hyperplastic gastric polyp. Some of these may contain some malignant cells which somehow generate a hyperplastic/reactive/inflammatory reaction around themselves.  However, most hyperplastic gastric polyps are benign and arise secondary to a Helicobacter pylori gastritis. For this reason, you should always do a CLO test in these cases.  

Every few weeks, I look up the notes on Prof Pritchard's' Podcast on gastric NET's to remind myself of the workup of these cases.  As you remember, you should take samples to confirm an atrophic gastritis whenever you find a gastric NET.  In this case, the patient did NOT have an atrophic gastritis. Instead, there was a Hp associated gastritis which is the reason for the second polyp. 

We realised that what we had was a TYPE II gastric NET! Analysis confirmed that the 17mm was WHO grade II. The finding of anything else than an innocent Type I gastric NET means that further imaging was required.  A little late in the day of course but fortunately, the following imaging investigations were unremarkable: 

• CT
• 68Gallium DOTA-peptide PET/CT scan
• EUS to search for duodenal wall gastrinomas and small gastrinomas within the pancreas which CT can't see and to search for lymphadenopathy close to the NET

Anyway, below is a reminder of what to do at gastroscopy, when you have a case of gastric NET: 

• Look for atrophic gastritis 
• Consider using some pH indicator strips to measure the gastric pH (unless pt is taking PPI)
• Identify all the NETs, record their size and number and sample them for histology and grading
• Take antral and corpus biopsies and ask pathologist to do report on the presence/absence of gastric atrophy and intestinal metaplasia and also ask them to carry out immunohistochemistry stains for ‘gastrin’ in the antral biopsies and ‘chromogranin’ and ‘synaptophysin’ in the gastric body samples.
• Look into the second part of the duodenum for the small submucosal gastrinomas which occasionally are seen in MEN-I
• Consider samples for Coeliac disease if the patient has an iron deficiency anaemia