Polyp glimpsed from the duodenal cap

This odd little polyp glimpsed just beyond the pyloric ring.  It was a bugger to remove as it proved impossible to retrovert in the duodenal cap.  In the end it was possible by pulling it into my snare, using a double channelled gastroscope. The histology is attached.

WHAT IS THE DIAGNOSIS ?
a) gastric heterotopia
b) pyloric gland adenoma
c) duodenal adenoma
d) Brunner's gland hyperplasia
e) Neuroendocrine tumour

Explanation

OK, there is no way to beat around the bush. This turned out to be a 'pyloric gland adenoma'. I don't think that there is any way that I could have distinguished this from a 'normal' duodenal adenoma endoscopically (you also have the histology to help you though). A Brunner's gland polyp is unlikely as the lesion isn't a beautiful, symmetrical submucosal ball, covered with normal duodenal mucosa. Gastric heterotopia is never this 'polypoid' or 'flamboyant'. Finally, a NET is unlikely as these should also be 'balls', classically with a central depression in the duodenum. 

The first time I came across a 'Pyloric gland adenoma', I objected to the histology because the polyp was situated in the stomach. Our lovely pathologist patiently educated me and explained that in spite of the name, they don't necessarily arise from the pylorus.  Instead, they got their name from the fact that they arise from 'pyloric glands' which are found in the oesophagus, stomach, pylorus and the duodenal cap.  

Furthermore, I didn't know that gastric adenomas are broadly classified into two types: 1) Gastric type and 2) the Intestinal type of gastric adenoma.   Gastric-type adenomas are further subclassified into 'pyloric gland adenomas' and 'foveolar-type adenoma'.  However, it's the intestinal-type adenomas which we endoscopists usually refer to as 'adenomas' in the upper GI tract. 

Pyloric gland adenomas are found in patients with Helicobacter pylori associated gastritis and 'chemical gastritis'. However, they are indeed 'neoplastic' (the cells are unstable) and may harbour low-grade dysplasia, high-grade dysplasia or even cancer.  If you would like to learn more about 'Pyloric gland adenomas', this is a good link: http://www.archivesofpathology.org/doi/pdf/10.5858/arpa.2013-0613-RS