Giant brunneroma originating from pylorus imitating duodenopancreatic malignancy. 
Brunner's gland adenoma is usually asymptomatic and sometimes accompanied by nausea, vomiting and swelling.  İt is often confused with duodenal malignancy, which may mislead and the physician about its treatment.  We want to present a case of a 40-year-old female with a history of weight loss, vomiting and nausea since six months.  İnitial imaging studies that revealed a large mass in the duodenum and endoscopic findings that suggested duodenal invagination.  Whipple operation had been recommended to the patient by two different general surgery departments.  The patient reported to our clinic for gastroenterological evaluation before the operation.  At our exmination, a giant polyp, 5 to 6 cm in size, was observed in the second part of the duodenum; it was 9 to 10 cm long and originated from the pylorus.  Duodenotomy was performed, and only the giant polyp was removed.  Pathological examination revealed hyperplastic Brunner's glands mixed with fibromuscular tissue and mature fat tissue.