Sporadic Non-ampullary Duodenal Adenoma Overriding the Cystic Dilatation of Brunner's Gland Hyperplasia.

Sporadic non-ampullary duodenal adenoma is uncommon and found incidentally during endoscopic examinations. Brunner's gland hyperplasia is commonly encountered during endoscopic examinations. Adenomas arising from Brunner's gland hyperplasia originate from the glandular cells, and the surface epithelia are usually intact. Little has been reported on adenomas originating from the surface epithelium that overrides Brunner's gland hyperplasia. Here, we report a case of a sporadic non-ampullary duodenal adenoma overriding the cystic dilatation of Brunner's gland hyperplasia.