*3.2.2 Brunner's gland hyperplasia*

Brunner's glands are found in the duodenum and have an alkaline secretion, neutralizing stomach acid. Hyperplasia of these glands is usually asymptomatic, but can give a polyposis-like duodenum. The cause is thought to be excessive stimulation from excessive gastric acids, chronic inflammation or the decrease of pancreatic function. They are located mainly, if not exclusively, in the duodenal bulb [5].

Echoendoscopic appearance can vary as isoechoic or hyperechoic, sometimes with cysts inside. They arise from the third layer (submucosa) and much more rarely from the second one (deep mucosa). The diagnosis is based on biopsy result (**Figure 1**).
