Some observations on pyloric gland adenoma: an uncommon and long ignored entity!

Pyloric gland adenomas (PGAs) are uncommon to rare and are found mostly in the stomach but in a number of other anatomical sites as well. They were recognized years ago by European and Japanese colleagues whereas North American pathologists learned to diagnose them more recently. They are associated with conditions that result in pyloric metaplasia, the prototype of which is autoimmune gastritis. Since the latter is more common in women and men, gastric PGA has a striking female predominance. There appear to be differences in the distribution of PGA in various populations. Herein we review PGA and note similarities and differences in their distribution in our institutions in Germany and the U.S.A. and review their morphological appearance, immunolabelling profile, and preliminary genetic data on these unusual lesions.